[PATCH v5 0/3] Add riscv semihosting support in u-boot

[PATCH v5 0/3] Add riscv semihosting support in u-boot

[Kautuk Consul]

Semihosting is a mechanism that enables code running on
a target to communicate and use the Input/Output
facilities on a host computer that is running a debugger.
This patchset adds support for semihosting in u-boot
for RISCV64 targets.

CHANGES since v4:
-	Check arch dependencies for SEMIHOSTING as well as SPL_SEMIHOSTING
	config options as per Sean's comment.
-	arch/riscv/lib/interrupts.c: Check for post and pre instructions
	of the ebreak statement whether they are as per the RISCV
	semihosting specification. Only then do a disable_semihosting
	and epc += 4 and return.

Compilation and test commands for SPL and S-mode configurations
=================================================================

U-Boot S-mode on QEMU virt
----------------------------
// Compilation of S-mode u-boot
ARCH=riscv
CROSS_COMPILE=riscv64-unknown-linux-gnu-
make qemu-riscv64_smode_defconfig
make
// Run riscv 64-bit u-boot with opensbi on qemu
qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
u-boot/u-boot.bin

U-Boot SPL on QEMU virt
------------------------
// Compilation of u-boot-spl
ARCH=riscv
CROSS_COMPILE=riscv64-unknown-linux-gnu-
make qemu-riscv64_spl_defconfig
make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
// Run 64-bit u-boot-spl in qemu
qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
u-boot/spl/u-boot-spl.bin -device\
loader,file=u-boot/u-boot.itb,addr=0x80200000

Kautuk Consul (3):
  lib: Add common semihosting library
  arch/riscv: add semihosting support for RISC-V
  board: qemu-riscv: enable semihosting

 arch/arm/Kconfig                     |  46 -------
 arch/arm/lib/semihosting.c           | 181 +-------------------------
 arch/riscv/include/asm/spl.h         |   1 +
 arch/riscv/lib/Makefile              |   2 +
 arch/riscv/lib/interrupts.c          |  25 ++++
 arch/riscv/lib/semihosting.c         |  24 ++++
 configs/qemu-riscv32_defconfig       |   4 +
 configs/qemu-riscv32_smode_defconfig |   4 +
 configs/qemu-riscv32_spl_defconfig   |   7 +
 configs/qemu-riscv64_defconfig       |   4 +
 configs/qemu-riscv64_smode_defconfig |   4 +
 configs/qemu-riscv64_spl_defconfig   |   7 +
 include/semihosting.h                |  11 ++
 lib/Kconfig                          |  47 +++++++
 lib/Makefile                         |   2 +
 lib/semihosting.c                    | 186 +++++++++++++++++++++++++++
 16 files changed, 329 insertions(+), 226 deletions(-)
 create mode 100644 arch/riscv/lib/semihosting.c
 create mode 100644 lib/semihosting.c

-- 
2.34.1

[PATCH v5 1/3] lib: Add common semihosting library

[Kautuk Consul]

We factor out the arch-independent parts of the ARM semihosting
implementation as a common library so that it can be shared
with RISC-V.

Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
---
 arch/arm/Kconfig           |  46 ---------
 arch/arm/lib/semihosting.c | 181 +-----------------------------------
 include/semihosting.h      |  11 +++
 lib/Kconfig                |  47 ++++++++++
 lib/Makefile               |   2 +
 lib/semihosting.c          | 186 +++++++++++++++++++++++++++++++++++++
 6 files changed, 247 insertions(+), 226 deletions(-)
 create mode 100644 lib/semihosting.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 82cd456f51..ee6a9fadd9 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -413,52 +413,6 @@ config ARM_SMCCC
 	  This should be enabled if U-Boot needs to communicate with system
 	  firmware (for example, PSCI) according to SMCCC.
 
-config SEMIHOSTING
-	bool "Support ARM semihosting"
-	help
-	  Semihosting is a method for a target to communicate with a host
-	  debugger. It uses special instructions which the debugger will trap
-	  on and interpret. This allows U-Boot to read/write files, print to
-	  the console, and execute arbitrary commands on the host system.
-
-	  Enabling this option will add support for reading and writing files
-	  on the host system. If you don't have a debugger attached then trying
-	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
-
-config SEMIHOSTING_FALLBACK
-	bool "Recover gracefully when semihosting fails"
-	depends on SEMIHOSTING && ARM64
-	default y
-	help
-	  Normally, if U-Boot makes a semihosting call and no debugger is
-	  attached, then it will panic due to a synchronous abort
-	  exception. This config adds an exception handler which will allow
-	  U-Boot to recover. Say 'y' if unsure.
-
-config SPL_SEMIHOSTING
-	bool "Support ARM semihosting in SPL"
-	depends on SPL
-	help
-	  Semihosting is a method for a target to communicate with a host
-	  debugger. It uses special instructions which the debugger will trap
-	  on and interpret. This allows U-Boot to read/write files, print to
-	  the console, and execute arbitrary commands on the host system.
-
-	  Enabling this option will add support for reading and writing files
-	  on the host system. If you don't have a debugger attached then trying
-	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
-
-config SPL_SEMIHOSTING_FALLBACK
-	bool "Recover gracefully when semihosting fails in SPL"
-	depends on SPL_SEMIHOSTING && ARM64
-	select ARMV8_SPL_EXCEPTION_VECTORS
-	default y
-	help
-	  Normally, if U-Boot makes a semihosting call and no debugger is
-	  attached, then it will panic due to a synchronous abort
-	  exception. This config adds an exception handler which will allow
-	  U-Boot to recover. Say 'y' if unsure.
-
 config SYS_THUMB_BUILD
 	bool "Build U-Boot using the Thumb instruction set"
 	depends on !ARM64
diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index 01d652a6b8..11e7b85ee6 100644
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -10,25 +10,11 @@
  * available in silicon now, fastmodel usage makes less sense for them.
  */
 #include <common.h>
-#include <log.h>
-#include <semihosting.h>
-
-#define SYSOPEN		0x01
-#define SYSCLOSE	0x02
-#define SYSWRITEC	0x03
-#define SYSWRITE0	0x04
-#define SYSWRITE	0x05
-#define SYSREAD		0x06
-#define SYSREADC	0x07
-#define SYSISERROR	0x08
-#define SYSSEEK		0x0A
-#define SYSFLEN		0x0C
-#define SYSERRNO	0x13
 
 /*
  * Call the handler
  */
-static noinline long smh_trap(unsigned int sysnum, void *addr)
+long smh_trap(unsigned int sysnum, void *addr)
 {
 	register long result asm("r0");
 #if defined(CONFIG_ARM64)
@@ -41,168 +27,3 @@ static noinline long smh_trap(unsigned int sysnum, void *addr)
 #endif
 	return result;
 }
-
-#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
-static bool _semihosting_enabled = true;
-static bool try_semihosting = true;
-
-bool semihosting_enabled(void)
-{
-	if (try_semihosting) {
-		smh_trap(SYSERRNO, NULL);
-		try_semihosting = false;
-	}
-
-	return _semihosting_enabled;
-}
-
-void disable_semihosting(void)
-{
-	_semihosting_enabled = false;
-}
-#endif
-
-/**
- * smh_errno() - Read the host's errno
- *
- * This gets the value of the host's errno and negates it. The host's errno may
- * or may not be set, so only call this function if a previous semihosting call
- * has failed.
- *
- * Return: a negative error value
- */
-static int smh_errno(void)
-{
-	long ret = smh_trap(SYSERRNO, NULL);
-
-	if (ret > 0 && ret < INT_MAX)
-		return -ret;
-	return -EIO;
-}
-
-long smh_open(const char *fname, enum smh_open_mode mode)
-{
-	long fd;
-	struct smh_open_s {
-		const char *fname;
-		unsigned long mode;
-		size_t len;
-	} open;
-
-	debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
-
-	open.fname = fname;
-	open.len = strlen(fname);
-	open.mode = mode;
-
-	/* Open the file on the host */
-	fd = smh_trap(SYSOPEN, &open);
-	if (fd == -1)
-		return smh_errno();
-	return fd;
-}
-
-/**
- * struct smg_rdwr_s - Arguments for read and write
- * @fd: A file descriptor returned from smh_open()
- * @memp: Pointer to a buffer of memory of at least @len bytes
- * @len: The number of bytes to read or write
- */
-struct smh_rdwr_s {
-	long fd;
-	void *memp;
-	size_t len;
-};
-
-long smh_read(long fd, void *memp, size_t len)
-{
-	long ret;
-	struct smh_rdwr_s read;
-
-	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
-
-	read.fd = fd;
-	read.memp = memp;
-	read.len = len;
-
-	ret = smh_trap(SYSREAD, &read);
-	if (ret < 0)
-		return smh_errno();
-	return len - ret;
-}
-
-long smh_write(long fd, const void *memp, size_t len, ulong *written)
-{
-	long ret;
-	struct smh_rdwr_s write;
-
-	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
-
-	write.fd = fd;
-	write.memp = (void *)memp;
-	write.len = len;
-
-	ret = smh_trap(SYSWRITE, &write);
-	*written = len - ret;
-	if (ret)
-		return smh_errno();
-	return 0;
-}
-
-long smh_close(long fd)
-{
-	long ret;
-
-	debug("%s: fd %ld\n", __func__, fd);
-
-	ret = smh_trap(SYSCLOSE, &fd);
-	if (ret == -1)
-		return smh_errno();
-	return 0;
-}
-
-long smh_flen(long fd)
-{
-	long ret;
-
-	debug("%s: fd %ld\n", __func__, fd);
-
-	ret = smh_trap(SYSFLEN, &fd);
-	if (ret == -1)
-		return smh_errno();
-	return ret;
-}
-
-long smh_seek(long fd, long pos)
-{
-	long ret;
-	struct smh_seek_s {
-		long fd;
-		long pos;
-	} seek;
-
-	debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
-
-	seek.fd = fd;
-	seek.pos = pos;
-
-	ret = smh_trap(SYSSEEK, &seek);
-	if (ret)
-		return smh_errno();
-	return 0;
-}
-
-int smh_getc(void)
-{
-	return smh_trap(SYSREADC, NULL);
-}
-
-void smh_putc(char ch)
-{
-	smh_trap(SYSWRITEC, &ch);
-}
-
-void smh_puts(const char *s)
-{
-	smh_trap(SYSWRITE0, (char *)s);
-}
diff --git a/include/semihosting.h b/include/semihosting.h
index f1f73464e4..4e844cbad8 100644
--- a/include/semihosting.h
+++ b/include/semihosting.h
@@ -17,6 +17,17 @@
 #define SMH_T32_SVC 0xDFAB
 #define SMH_T32_HLT 0xBABC
 
+/**
+ * smh_trap() - ARCH-specific semihosting call.
+ *
+ * Semihosting library/driver can use this function to do the
+ * actual semihosting calls.
+ *
+ * Return: Error code defined by semihosting spec.
+ */
+
+long smh_trap(unsigned int sysnum, void *addr);
+
 #if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
 /**
  * semihosting_enabled() - Determine whether semihosting is supported
diff --git a/lib/Kconfig b/lib/Kconfig
index 6121c80dc8..de7e797f11 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -71,6 +71,53 @@ config HAVE_PRIVATE_LIBGCC
 config LIB_UUID
 	bool
 
+config SEMIHOSTING
+	bool "Support semihosting"
+	depends on ARM
+	help
+	  Semihosting is a method for a target to communicate with a host
+	  debugger. It uses special instructions which the debugger will trap
+	  on and interpret. This allows U-Boot to read/write files, print to
+	  the console, and execute arbitrary commands on the host system.
+
+	  Enabling this option will add support for reading and writing files
+	  on the host system. If you don't have a debugger attached then trying
+	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
+
+config SEMIHOSTING_FALLBACK
+	bool "Recover gracefully when semihosting fails"
+	depends on SEMIHOSTING && ARM64
+	default y
+	help
+	  Normally, if U-Boot makes a semihosting call and no debugger is
+	  attached, then it will panic due to a synchronous abort
+	  exception. This config adds an exception handler which will allow
+	  U-Boot to recover. Say 'y' if unsure.
+
+config SPL_SEMIHOSTING
+	bool "Support semihosting in SPL"
+	depends on SPL && ARM
+	help
+	  Semihosting is a method for a target to communicate with a host
+	  debugger. It uses special instructions which the debugger will trap
+	  on and interpret. This allows U-Boot to read/write files, print to
+	  the console, and execute arbitrary commands on the host system.
+
+	  Enabling this option will add support for reading and writing files
+	  on the host system. If you don't have a debugger attached then trying
+	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
+
+config SPL_SEMIHOSTING_FALLBACK
+	bool "Recover gracefully when semihosting fails in SPL"
+	depends on SPL_SEMIHOSTING && ARM64
+	select ARMV8_SPL_EXCEPTION_VECTORS
+	default y
+	help
+	  Normally, if U-Boot makes a semihosting call and no debugger is
+	  attached, then it will panic due to a synchronous abort
+	  exception. This config adds an exception handler which will allow
+	  U-Boot to recover. Say 'y' if unsure.
+
 config PRINTF
 	bool
 	default y
diff --git a/lib/Makefile b/lib/Makefile
index e3deb15287..134c4319cd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -145,6 +145,8 @@ obj-y += date.o
 obj-y += rtc-lib.o
 obj-$(CONFIG_LIB_ELF) += elf.o
 
+obj-$(CONFIG_$(SPL_TPL_)SEMIHOSTING) += semihosting.o
+
 #
 # Build a fast OID lookup registry from include/linux/oid_registry.h
 #
diff --git a/lib/semihosting.c b/lib/semihosting.c
new file mode 100644
index 0000000000..831774e356
--- /dev/null
+++ b/lib/semihosting.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
+ * Copyright 2014 Broadcom Corporation
+ */
+
+#include <common.h>
+#include <log.h>
+#include <semihosting.h>
+
+#define SYSOPEN		0x01
+#define SYSCLOSE	0x02
+#define SYSWRITEC	0x03
+#define SYSWRITE0	0x04
+#define SYSWRITE	0x05
+#define SYSREAD		0x06
+#define SYSREADC	0x07
+#define SYSISERROR	0x08
+#define SYSSEEK		0x0A
+#define SYSFLEN		0x0C
+#define SYSERRNO	0x13
+
+#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
+static bool _semihosting_enabled = true;
+static bool try_semihosting = true;
+
+bool semihosting_enabled(void)
+{
+	if (try_semihosting) {
+		smh_trap(SYSERRNO, NULL);
+		try_semihosting = false;
+	}
+
+	return _semihosting_enabled;
+}
+
+void disable_semihosting(void)
+{
+	_semihosting_enabled = false;
+}
+#endif
+
+/**
+ * smh_errno() - Read the host's errno
+ *
+ * This gets the value of the host's errno and negates it. The host's errno may
+ * or may not be set, so only call this function if a previous semihosting call
+ * has failed.
+ *
+ * Return: a negative error value
+ */
+static int smh_errno(void)
+{
+	long ret = smh_trap(SYSERRNO, NULL);
+
+	if (ret > 0 && ret < INT_MAX)
+		return -ret;
+	return -EIO;
+}
+
+long smh_open(const char *fname, enum smh_open_mode mode)
+{
+	long fd;
+	struct smh_open_s {
+		const char *fname;
+		unsigned long mode;
+		size_t len;
+	} open;
+
+	debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
+
+	open.fname = fname;
+	open.len = strlen(fname);
+	open.mode = mode;
+
+	/* Open the file on the host */
+	fd = smh_trap(SYSOPEN, &open);
+	if (fd == -1)
+		return smh_errno();
+	return fd;
+}
+
+/**
+ * struct smg_rdwr_s - Arguments for read and write
+ * @fd: A file descriptor returned from smh_open()
+ * @memp: Pointer to a buffer of memory of at least @len bytes
+ * @len: The number of bytes to read or write
+ */
+struct smh_rdwr_s {
+	long fd;
+	void *memp;
+	size_t len;
+};
+
+long smh_read(long fd, void *memp, size_t len)
+{
+	long ret;
+	struct smh_rdwr_s read;
+
+	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
+
+	read.fd = fd;
+	read.memp = memp;
+	read.len = len;
+
+	ret = smh_trap(SYSREAD, &read);
+	if (ret < 0)
+		return smh_errno();
+	return len - ret;
+}
+
+long smh_write(long fd, const void *memp, size_t len, ulong *written)
+{
+	long ret;
+	struct smh_rdwr_s write;
+
+	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
+
+	write.fd = fd;
+	write.memp = (void *)memp;
+	write.len = len;
+
+	ret = smh_trap(SYSWRITE, &write);
+	*written = len - ret;
+	if (ret)
+		return smh_errno();
+	return 0;
+}
+
+long smh_close(long fd)
+{
+	long ret;
+
+	debug("%s: fd %ld\n", __func__, fd);
+
+	ret = smh_trap(SYSCLOSE, &fd);
+	if (ret == -1)
+		return smh_errno();
+	return 0;
+}
+
+long smh_flen(long fd)
+{
+	long ret;
+
+	debug("%s: fd %ld\n", __func__, fd);
+
+	ret = smh_trap(SYSFLEN, &fd);
+	if (ret == -1)
+		return smh_errno();
+	return ret;
+}
+
+long smh_seek(long fd, long pos)
+{
+	long ret;
+	struct smh_seek_s {
+		long fd;
+		long pos;
+	} seek;
+
+	debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
+
+	seek.fd = fd;
+	seek.pos = pos;
+
+	ret = smh_trap(SYSSEEK, &seek);
+	if (ret)
+		return smh_errno();
+	return 0;
+}
+
+int smh_getc(void)
+{
+	return smh_trap(SYSREADC, NULL);
+}
+
+void smh_putc(char ch)
+{
+	smh_trap(SYSWRITEC, &ch);
+}
+
+void smh_puts(const char *s)
+{
+	smh_trap(SYSWRITE0, (char *)s);
+}
-- 
2.34.1

[PATCH v5 2/3] arch/riscv: add semihosting support for RISC-V

[Kautuk Consul]

We add RISC-V semihosting based serial console for JTAG based early
debugging.

The RISC-V semihosting specification is available at:
https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
---
 arch/riscv/include/asm/spl.h |  1 +
 arch/riscv/lib/Makefile      |  2 ++
 arch/riscv/lib/interrupts.c  | 25 +++++++++++++++++++++++++
 arch/riscv/lib/semihosting.c | 24 ++++++++++++++++++++++++
 lib/Kconfig                  | 10 +++++-----
 5 files changed, 57 insertions(+), 5 deletions(-)
 create mode 100644 arch/riscv/lib/semihosting.c

diff --git a/arch/riscv/include/asm/spl.h b/arch/riscv/include/asm/spl.h
index e8a94fcb1f..2898a770ee 100644
--- a/arch/riscv/include/asm/spl.h
+++ b/arch/riscv/include/asm/spl.h
@@ -25,6 +25,7 @@ enum {
 	BOOT_DEVICE_DFU,
 	BOOT_DEVICE_XIP,
 	BOOT_DEVICE_BOOTROM,
+	BOOT_DEVICE_SMH,
 	BOOT_DEVICE_NONE
 };
 
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 06020fcc2a..64e29804c1 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -42,3 +42,5 @@ extra-$(CONFIG_EFI) += $(EFI_CRT0) $(EFI_RELOC)
 obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMSET) += memset.o
 obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMMOVE) += memmove.o
 obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMCPY) += memcpy.o
+
+obj-$(CONFIG_$(SPL_TPL_)SEMIHOSTING) += semihosting.o
diff --git a/arch/riscv/lib/interrupts.c b/arch/riscv/lib/interrupts.c
index 100be2e966..e966afa7e3 100644
--- a/arch/riscv/lib/interrupts.c
+++ b/arch/riscv/lib/interrupts.c
@@ -9,6 +9,7 @@
  * Copyright (C) 2019 Sean Anderson <seanga2@gmail.com>
  */
 
+#include <linux/compat.h>
 #include <common.h>
 #include <efi_loader.h>
 #include <hang.h>
@@ -17,6 +18,7 @@
 #include <asm/ptrace.h>
 #include <asm/system.h>
 #include <asm/encoding.h>
+#include <semihosting.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -149,6 +151,29 @@ ulong handle_trap(ulong cause, ulong epc, ulong tval, struct pt_regs *regs)
 	/* An UEFI application may have changed gd. Restore U-Boot's gd. */
 	efi_restore_gd();
 
+	if (cause == CAUSE_BREAKPOINT &&
+	    CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)) {
+		ulong pre_addr = epc - 4, post_addr = epc + 4;
+
+		/* Check for prior and post addresses to be in same page. */
+		if ((pre_addr & ~(PAGE_SIZE - 1)) ==
+			(post_addr & ~(PAGE_SIZE - 1))) {
+			u32 pre = *(u32 *)pre_addr;
+			u32 post = *(u32 *)post_addr;
+
+			/* Check for semihosting, i.e.:
+			 * slli    zero,zero,0x1f
+			 * ebreak
+			 * srai    zero,zero,0x7
+			 */
+			if (pre == 0x01f01013 && post == 0x40705013) {
+				disable_semihosting();
+				epc += 4;
+				return epc;
+			}
+		}
+	}
+
 	is_irq = (cause & MCAUSE_INT);
 	irq = (cause & ~MCAUSE_INT);
 
diff --git a/arch/riscv/lib/semihosting.c b/arch/riscv/lib/semihosting.c
new file mode 100644
index 0000000000..d6593b02a6
--- /dev/null
+++ b/arch/riscv/lib/semihosting.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <common.h>
+
+long smh_trap(int sysnum, void *addr)
+{
+	register int ret asm ("a0") = sysnum;
+	register void *param0 asm ("a1") = addr;
+
+	asm volatile (".align 4\n"
+		".option push\n"
+		".option norvc\n"
+
+		"slli zero, zero, 0x1f\n"
+		"ebreak\n"
+		"srai zero, zero, 7\n"
+		".option pop\n"
+		: "+r" (ret) : "r" (param0) : "memory");
+
+	return ret;
+}
diff --git a/lib/Kconfig b/lib/Kconfig
index de7e797f11..2cc556ee8a 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -73,7 +73,7 @@ config LIB_UUID
 
 config SEMIHOSTING
 	bool "Support semihosting"
-	depends on ARM
+	depends on ARM || RISCV
 	help
 	  Semihosting is a method for a target to communicate with a host
 	  debugger. It uses special instructions which the debugger will trap
@@ -86,7 +86,7 @@ config SEMIHOSTING
 
 config SEMIHOSTING_FALLBACK
 	bool "Recover gracefully when semihosting fails"
-	depends on SEMIHOSTING && ARM64
+	depends on SEMIHOSTING && (ARM64 || RISCV)
 	default y
 	help
 	  Normally, if U-Boot makes a semihosting call and no debugger is
@@ -96,7 +96,7 @@ config SEMIHOSTING_FALLBACK
 
 config SPL_SEMIHOSTING
 	bool "Support semihosting in SPL"
-	depends on SPL && ARM
+	depends on SPL && (ARM || RISCV)
 	help
 	  Semihosting is a method for a target to communicate with a host
 	  debugger. It uses special instructions which the debugger will trap
@@ -109,8 +109,8 @@ config SPL_SEMIHOSTING
 
 config SPL_SEMIHOSTING_FALLBACK
 	bool "Recover gracefully when semihosting fails in SPL"
-	depends on SPL_SEMIHOSTING && ARM64
-	select ARMV8_SPL_EXCEPTION_VECTORS
+	depends on SPL_SEMIHOSTING && (ARM64 || RISCV)
+	select ARMV8_SPL_EXCEPTION_VECTORS if ARM64
 	default y
 	help
 	  Normally, if U-Boot makes a semihosting call and no debugger is
-- 
2.34.1

[PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

To enable semihosting we also need to enable the following
configs in defconfigs:
CONFIG_SEMIHOSTING
CONFIG_SPL_SEMIHOSTING
CONFIG_SEMIHOSTING_SERIAL
CONFIG_SERIAL_PROBE_ALL
CONFIG_SPL_FS_EXT4
CONFIG_SPL_FS_FAT

Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
---
 configs/qemu-riscv32_defconfig       | 4 ++++
 configs/qemu-riscv32_smode_defconfig | 4 ++++
 configs/qemu-riscv32_spl_defconfig   | 7 +++++++
 configs/qemu-riscv64_defconfig       | 4 ++++
 configs/qemu-riscv64_smode_defconfig | 4 ++++
 configs/qemu-riscv64_spl_defconfig   | 7 +++++++
 6 files changed, 30 insertions(+)

diff --git a/configs/qemu-riscv32_defconfig b/configs/qemu-riscv32_defconfig
index 9634d7f77f..4961652548 100644
--- a/configs/qemu-riscv32_defconfig
+++ b/configs/qemu-riscv32_defconfig
@@ -1,4 +1,5 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
@@ -20,3 +21,6 @@ CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
diff --git a/configs/qemu-riscv32_smode_defconfig b/configs/qemu-riscv32_smode_defconfig
index 1c5a0617aa..91e4ffebc2 100644
--- a/configs/qemu-riscv32_smode_defconfig
+++ b/configs/qemu-riscv32_smode_defconfig
@@ -1,4 +1,5 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
@@ -21,4 +22,7 @@ CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
 CONFIG_SYSRESET_SBI=y
diff --git a/configs/qemu-riscv32_spl_defconfig b/configs/qemu-riscv32_spl_defconfig
index 2421c9a371..5fd28fc58c 100644
--- a/configs/qemu-riscv32_spl_defconfig
+++ b/configs/qemu-riscv32_spl_defconfig
@@ -1,9 +1,12 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
+CONFIG_SPL_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
 CONFIG_DEFAULT_DEVICE_TREE="qemu-virt32"
 CONFIG_SPL=y
+CONFIG_SPL_FS_FAT=y
 CONFIG_SYS_LOAD_ADDR=0x80200000
 CONFIG_TARGET_QEMU_VIRT=y
 CONFIG_RISCV_SMODE=y
@@ -18,6 +21,7 @@ CONFIG_DISPLAY_BOARDINFO=y
 CONFIG_SPL_MAX_SIZE=0x100000
 CONFIG_SPL_BSS_START_ADDR=0x84000000
 CONFIG_SYS_SPL_MALLOC=y
+CONFIG_SPL_FS_EXT4=y
 CONFIG_SYS_CBSIZE=256
 CONFIG_SYS_PBSIZE=276
 CONFIG_SYS_BOOTM_LEN=0x4000000
@@ -25,5 +29,8 @@ CONFIG_SYS_BOOTM_LEN=0x4000000
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
 CONFIG_SYSRESET_SBI=y
 # CONFIG_BINMAN_FDT is not set
diff --git a/configs/qemu-riscv64_defconfig b/configs/qemu-riscv64_defconfig
index d5eae95c80..87478f4481 100644
--- a/configs/qemu-riscv64_defconfig
+++ b/configs/qemu-riscv64_defconfig
@@ -1,4 +1,5 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
@@ -21,3 +22,6 @@ CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
diff --git a/configs/qemu-riscv64_smode_defconfig b/configs/qemu-riscv64_smode_defconfig
index 2861d07f97..5e9d6af3be 100644
--- a/configs/qemu-riscv64_smode_defconfig
+++ b/configs/qemu-riscv64_smode_defconfig
@@ -1,4 +1,5 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
@@ -24,4 +25,7 @@ CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
 CONFIG_SYSRESET_SBI=y
diff --git a/configs/qemu-riscv64_spl_defconfig b/configs/qemu-riscv64_spl_defconfig
index 1ecfa27ce2..e5d817b783 100644
--- a/configs/qemu-riscv64_spl_defconfig
+++ b/configs/qemu-riscv64_spl_defconfig
@@ -1,9 +1,12 @@
 CONFIG_RISCV=y
+CONFIG_SEMIHOSTING=y
+CONFIG_SPL_SEMIHOSTING=y
 CONFIG_SYS_MALLOC_LEN=0x800000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000
 CONFIG_DEFAULT_DEVICE_TREE="qemu-virt64"
 CONFIG_SPL=y
+CONFIG_SPL_FS_FAT=y
 CONFIG_SYS_LOAD_ADDR=0x80200000
 CONFIG_TARGET_QEMU_VIRT=y
 CONFIG_ARCH_RV64I=y
@@ -18,6 +21,7 @@ CONFIG_DISPLAY_BOARDINFO=y
 CONFIG_SPL_MAX_SIZE=0x100000
 CONFIG_SPL_BSS_START_ADDR=0x84000000
 CONFIG_SYS_SPL_MALLOC=y
+CONFIG_SPL_FS_EXT4=y
 CONFIG_SYS_CBSIZE=256
 CONFIG_SYS_PBSIZE=276
 CONFIG_SYS_BOOTM_LEN=0x4000000
@@ -25,5 +29,8 @@ CONFIG_SYS_BOOTM_LEN=0x4000000
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM_MTD=y
 CONFIG_SYS_MAX_FLASH_BANKS=2
+# CONFIG_SERIAL_PUTS is not set
+CONFIG_SERIAL_PROBE_ALL=y
+CONFIG_SEMIHOSTING_SERIAL=y
 CONFIG_SYSRESET_SBI=y
 # CONFIG_BINMAN_FDT is not set
-- 
2.34.1

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Leo Liang]

Hi Kautuk,

On Fri, Sep 23, 2022 at 12:33:20PM +0530, Kautuk Consul wrote:
> To enable semihosting we also need to enable the following
> configs in defconfigs:
> CONFIG_SEMIHOSTING
> CONFIG_SPL_SEMIHOSTING
> CONFIG_SEMIHOSTING_SERIAL
> CONFIG_SERIAL_PROBE_ALL
> CONFIG_SPL_FS_EXT4
> CONFIG_SPL_FS_FAT
> 
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  configs/qemu-riscv32_defconfig       | 4 ++++
>  configs/qemu-riscv32_smode_defconfig | 4 ++++
>  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
>  configs/qemu-riscv64_defconfig       | 4 ++++
>  configs/qemu-riscv64_smode_defconfig | 4 ++++
>  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
>  6 files changed, 30 insertions(+)

This patch set seems to cause some CI error.
(https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/13667)
Could you please take a look at it?

Besides, will anything go wrong if we do not attach a debugger but enable semihosting on qemu?

Best regards,
Leo

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

Hi Leo,

I took a look at the raw log.
It seems that the test-case is outputting too many characters onto the
u-boot prompt
due to which the log size has gotten exceeded. Can you somehow increase the log
size and then try ?

Thanks.

On Wed, Oct 5, 2022 at 11:47 AM Leo Liang <ycliang@andestech.com> wrote:
>
> Hi Kautuk,
>
> On Fri, Sep 23, 2022 at 12:33:20PM +0530, Kautuk Consul wrote:
> > To enable semihosting we also need to enable the following
> > configs in defconfigs:
> > CONFIG_SEMIHOSTING
> > CONFIG_SPL_SEMIHOSTING
> > CONFIG_SEMIHOSTING_SERIAL
> > CONFIG_SERIAL_PROBE_ALL
> > CONFIG_SPL_FS_EXT4
> > CONFIG_SPL_FS_FAT
> >
> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > ---
> >  configs/qemu-riscv32_defconfig       | 4 ++++
> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> >  configs/qemu-riscv64_defconfig       | 4 ++++
> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> >  6 files changed, 30 insertions(+)
>
> This patch set seems to cause some CI error.
> (https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/13667)
> Could you please take a look at it?
>
> Besides, will anything go wrong if we do not attach a debugger but enable semihosting on qemu?
>
> Best regards,
> Leo

Re: [PATCH v5 1/3] lib: Add common semihosting library

[Sean Anderson]

On 9/23/22 3:03 AM, Kautuk Consul wrote:
> We factor out the arch-independent parts of the ARM semihosting
> implementation as a common library so that it can be shared
> with RISC-V.
> 
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  arch/arm/Kconfig           |  46 ---------
>  arch/arm/lib/semihosting.c | 181 +-----------------------------------
>  include/semihosting.h      |  11 +++
>  lib/Kconfig                |  47 ++++++++++
>  lib/Makefile               |   2 +
>  lib/semihosting.c          | 186 +++++++++++++++++++++++++++++++++++++
>  6 files changed, 247 insertions(+), 226 deletions(-)
>  create mode 100644 lib/semihosting.c
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 82cd456f51..ee6a9fadd9 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -413,52 +413,6 @@ config ARM_SMCCC
>  	  This should be enabled if U-Boot needs to communicate with system
>  	  firmware (for example, PSCI) according to SMCCC.
>  
> -config SEMIHOSTING
> -	bool "Support ARM semihosting"
> -	help
> -	  Semihosting is a method for a target to communicate with a host
> -	  debugger. It uses special instructions which the debugger will trap
> -	  on and interpret. This allows U-Boot to read/write files, print to
> -	  the console, and execute arbitrary commands on the host system.
> -
> -	  Enabling this option will add support for reading and writing files
> -	  on the host system. If you don't have a debugger attached then trying
> -	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
> -
> -config SEMIHOSTING_FALLBACK
> -	bool "Recover gracefully when semihosting fails"
> -	depends on SEMIHOSTING && ARM64
> -	default y
> -	help
> -	  Normally, if U-Boot makes a semihosting call and no debugger is
> -	  attached, then it will panic due to a synchronous abort
> -	  exception. This config adds an exception handler which will allow
> -	  U-Boot to recover. Say 'y' if unsure.
> -
> -config SPL_SEMIHOSTING
> -	bool "Support ARM semihosting in SPL"
> -	depends on SPL
> -	help
> -	  Semihosting is a method for a target to communicate with a host
> -	  debugger. It uses special instructions which the debugger will trap
> -	  on and interpret. This allows U-Boot to read/write files, print to
> -	  the console, and execute arbitrary commands on the host system.
> -
> -	  Enabling this option will add support for reading and writing files
> -	  on the host system. If you don't have a debugger attached then trying
> -	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
> -
> -config SPL_SEMIHOSTING_FALLBACK
> -	bool "Recover gracefully when semihosting fails in SPL"
> -	depends on SPL_SEMIHOSTING && ARM64
> -	select ARMV8_SPL_EXCEPTION_VECTORS
> -	default y
> -	help
> -	  Normally, if U-Boot makes a semihosting call and no debugger is
> -	  attached, then it will panic due to a synchronous abort
> -	  exception. This config adds an exception handler which will allow
> -	  U-Boot to recover. Say 'y' if unsure.
> -
>  config SYS_THUMB_BUILD
>  	bool "Build U-Boot using the Thumb instruction set"
>  	depends on !ARM64
> diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
> index 01d652a6b8..11e7b85ee6 100644
> --- a/arch/arm/lib/semihosting.c
> +++ b/arch/arm/lib/semihosting.c
> @@ -10,25 +10,11 @@
>   * available in silicon now, fastmodel usage makes less sense for them.
>   */
>  #include <common.h>
> -#include <log.h>
> -#include <semihosting.h>
> -
> -#define SYSOPEN		0x01
> -#define SYSCLOSE	0x02
> -#define SYSWRITEC	0x03
> -#define SYSWRITE0	0x04
> -#define SYSWRITE	0x05
> -#define SYSREAD		0x06
> -#define SYSREADC	0x07
> -#define SYSISERROR	0x08
> -#define SYSSEEK		0x0A
> -#define SYSFLEN		0x0C
> -#define SYSERRNO	0x13
>  
>  /*
>   * Call the handler
>   */
> -static noinline long smh_trap(unsigned int sysnum, void *addr)
> +long smh_trap(unsigned int sysnum, void *addr)
>  {
>  	register long result asm("r0");
>  #if defined(CONFIG_ARM64)
> @@ -41,168 +27,3 @@ static noinline long smh_trap(unsigned int sysnum, void *addr)
>  #endif
>  	return result;
>  }
> -
> -#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
> -static bool _semihosting_enabled = true;
> -static bool try_semihosting = true;
> -
> -bool semihosting_enabled(void)
> -{
> -	if (try_semihosting) {
> -		smh_trap(SYSERRNO, NULL);
> -		try_semihosting = false;
> -	}
> -
> -	return _semihosting_enabled;
> -}
> -
> -void disable_semihosting(void)
> -{
> -	_semihosting_enabled = false;
> -}
> -#endif
> -
> -/**
> - * smh_errno() - Read the host's errno
> - *
> - * This gets the value of the host's errno and negates it. The host's errno may
> - * or may not be set, so only call this function if a previous semihosting call
> - * has failed.
> - *
> - * Return: a negative error value
> - */
> -static int smh_errno(void)
> -{
> -	long ret = smh_trap(SYSERRNO, NULL);
> -
> -	if (ret > 0 && ret < INT_MAX)
> -		return -ret;
> -	return -EIO;
> -}
> -
> -long smh_open(const char *fname, enum smh_open_mode mode)
> -{
> -	long fd;
> -	struct smh_open_s {
> -		const char *fname;
> -		unsigned long mode;
> -		size_t len;
> -	} open;
> -
> -	debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
> -
> -	open.fname = fname;
> -	open.len = strlen(fname);
> -	open.mode = mode;
> -
> -	/* Open the file on the host */
> -	fd = smh_trap(SYSOPEN, &open);
> -	if (fd == -1)
> -		return smh_errno();
> -	return fd;
> -}
> -
> -/**
> - * struct smg_rdwr_s - Arguments for read and write
> - * @fd: A file descriptor returned from smh_open()
> - * @memp: Pointer to a buffer of memory of at least @len bytes
> - * @len: The number of bytes to read or write
> - */
> -struct smh_rdwr_s {
> -	long fd;
> -	void *memp;
> -	size_t len;
> -};
> -
> -long smh_read(long fd, void *memp, size_t len)
> -{
> -	long ret;
> -	struct smh_rdwr_s read;
> -
> -	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
> -
> -	read.fd = fd;
> -	read.memp = memp;
> -	read.len = len;
> -
> -	ret = smh_trap(SYSREAD, &read);
> -	if (ret < 0)
> -		return smh_errno();
> -	return len - ret;
> -}
> -
> -long smh_write(long fd, const void *memp, size_t len, ulong *written)
> -{
> -	long ret;
> -	struct smh_rdwr_s write;
> -
> -	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
> -
> -	write.fd = fd;
> -	write.memp = (void *)memp;
> -	write.len = len;
> -
> -	ret = smh_trap(SYSWRITE, &write);
> -	*written = len - ret;
> -	if (ret)
> -		return smh_errno();
> -	return 0;
> -}
> -
> -long smh_close(long fd)
> -{
> -	long ret;
> -
> -	debug("%s: fd %ld\n", __func__, fd);
> -
> -	ret = smh_trap(SYSCLOSE, &fd);
> -	if (ret == -1)
> -		return smh_errno();
> -	return 0;
> -}
> -
> -long smh_flen(long fd)
> -{
> -	long ret;
> -
> -	debug("%s: fd %ld\n", __func__, fd);
> -
> -	ret = smh_trap(SYSFLEN, &fd);
> -	if (ret == -1)
> -		return smh_errno();
> -	return ret;
> -}
> -
> -long smh_seek(long fd, long pos)
> -{
> -	long ret;
> -	struct smh_seek_s {
> -		long fd;
> -		long pos;
> -	} seek;
> -
> -	debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
> -
> -	seek.fd = fd;
> -	seek.pos = pos;
> -
> -	ret = smh_trap(SYSSEEK, &seek);
> -	if (ret)
> -		return smh_errno();
> -	return 0;
> -}
> -
> -int smh_getc(void)
> -{
> -	return smh_trap(SYSREADC, NULL);
> -}
> -
> -void smh_putc(char ch)
> -{
> -	smh_trap(SYSWRITEC, &ch);
> -}
> -
> -void smh_puts(const char *s)
> -{
> -	smh_trap(SYSWRITE0, (char *)s);
> -}
> diff --git a/include/semihosting.h b/include/semihosting.h
> index f1f73464e4..4e844cbad8 100644
> --- a/include/semihosting.h
> +++ b/include/semihosting.h
> @@ -17,6 +17,17 @@
>  #define SMH_T32_SVC 0xDFAB
>  #define SMH_T32_HLT 0xBABC
>  
> +/**
> + * smh_trap() - ARCH-specific semihosting call.
> + *
> + * Semihosting library/driver can use this function to do the
> + * actual semihosting calls.
> + *
> + * Return: Error code defined by semihosting spec.
> + */
> +
> +long smh_trap(unsigned int sysnum, void *addr);
> +
>  #if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
>  /**
>   * semihosting_enabled() - Determine whether semihosting is supported
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 6121c80dc8..de7e797f11 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -71,6 +71,53 @@ config HAVE_PRIVATE_LIBGCC
>  config LIB_UUID
>  	bool
>  
> +config SEMIHOSTING
> +	bool "Support semihosting"
> +	depends on ARM
> +	help
> +	  Semihosting is a method for a target to communicate with a host
> +	  debugger. It uses special instructions which the debugger will trap
> +	  on and interpret. This allows U-Boot to read/write files, print to
> +	  the console, and execute arbitrary commands on the host system.
> +
> +	  Enabling this option will add support for reading and writing files
> +	  on the host system. If you don't have a debugger attached then trying
> +	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
> +
> +config SEMIHOSTING_FALLBACK
> +	bool "Recover gracefully when semihosting fails"
> +	depends on SEMIHOSTING && ARM64
> +	default y
> +	help
> +	  Normally, if U-Boot makes a semihosting call and no debugger is
> +	  attached, then it will panic due to a synchronous abort
> +	  exception. This config adds an exception handler which will allow
> +	  U-Boot to recover. Say 'y' if unsure.
> +
> +config SPL_SEMIHOSTING
> +	bool "Support semihosting in SPL"
> +	depends on SPL && ARM
> +	help
> +	  Semihosting is a method for a target to communicate with a host
> +	  debugger. It uses special instructions which the debugger will trap
> +	  on and interpret. This allows U-Boot to read/write files, print to
> +	  the console, and execute arbitrary commands on the host system.
> +
> +	  Enabling this option will add support for reading and writing files
> +	  on the host system. If you don't have a debugger attached then trying
> +	  to do this will likely cause U-Boot to hang. Say 'n' if you are unsure.
> +
> +config SPL_SEMIHOSTING_FALLBACK
> +	bool "Recover gracefully when semihosting fails in SPL"
> +	depends on SPL_SEMIHOSTING && ARM64
> +	select ARMV8_SPL_EXCEPTION_VECTORS
> +	default y
> +	help
> +	  Normally, if U-Boot makes a semihosting call and no debugger is
> +	  attached, then it will panic due to a synchronous abort
> +	  exception. This config adds an exception handler which will allow
> +	  U-Boot to recover. Say 'y' if unsure.
> +
>  config PRINTF
>  	bool
>  	default y
> diff --git a/lib/Makefile b/lib/Makefile
> index e3deb15287..134c4319cd 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -145,6 +145,8 @@ obj-y += date.o
>  obj-y += rtc-lib.o
>  obj-$(CONFIG_LIB_ELF) += elf.o
>  
> +obj-$(CONFIG_$(SPL_TPL_)SEMIHOSTING) += semihosting.o
> +
>  #
>  # Build a fast OID lookup registry from include/linux/oid_registry.h
>  #
> diff --git a/lib/semihosting.c b/lib/semihosting.c
> new file mode 100644
> index 0000000000..831774e356
> --- /dev/null
> +++ b/lib/semihosting.c
> @@ -0,0 +1,186 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
> + * Copyright 2014 Broadcom Corporation
> + */
> +
> +#include <common.h>
> +#include <log.h>
> +#include <semihosting.h>
> +
> +#define SYSOPEN		0x01
> +#define SYSCLOSE	0x02
> +#define SYSWRITEC	0x03
> +#define SYSWRITE0	0x04
> +#define SYSWRITE	0x05
> +#define SYSREAD		0x06
> +#define SYSREADC	0x07
> +#define SYSISERROR	0x08
> +#define SYSSEEK		0x0A
> +#define SYSFLEN		0x0C
> +#define SYSERRNO	0x13
> +
> +#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
> +static bool _semihosting_enabled = true;
> +static bool try_semihosting = true;
> +
> +bool semihosting_enabled(void)
> +{
> +	if (try_semihosting) {
> +		smh_trap(SYSERRNO, NULL);
> +		try_semihosting = false;
> +	}
> +
> +	return _semihosting_enabled;
> +}
> +
> +void disable_semihosting(void)
> +{
> +	_semihosting_enabled = false;
> +}
> +#endif
> +
> +/**
> + * smh_errno() - Read the host's errno
> + *
> + * This gets the value of the host's errno and negates it. The host's errno may
> + * or may not be set, so only call this function if a previous semihosting call
> + * has failed.
> + *
> + * Return: a negative error value
> + */
> +static int smh_errno(void)
> +{
> +	long ret = smh_trap(SYSERRNO, NULL);
> +
> +	if (ret > 0 && ret < INT_MAX)
> +		return -ret;
> +	return -EIO;
> +}
> +
> +long smh_open(const char *fname, enum smh_open_mode mode)
> +{
> +	long fd;
> +	struct smh_open_s {
> +		const char *fname;
> +		unsigned long mode;
> +		size_t len;
> +	} open;
> +
> +	debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
> +
> +	open.fname = fname;
> +	open.len = strlen(fname);
> +	open.mode = mode;
> +
> +	/* Open the file on the host */
> +	fd = smh_trap(SYSOPEN, &open);
> +	if (fd == -1)
> +		return smh_errno();
> +	return fd;
> +}
> +
> +/**
> + * struct smg_rdwr_s - Arguments for read and write
> + * @fd: A file descriptor returned from smh_open()
> + * @memp: Pointer to a buffer of memory of at least @len bytes
> + * @len: The number of bytes to read or write
> + */
> +struct smh_rdwr_s {
> +	long fd;
> +	void *memp;
> +	size_t len;
> +};
> +
> +long smh_read(long fd, void *memp, size_t len)
> +{
> +	long ret;
> +	struct smh_rdwr_s read;
> +
> +	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
> +
> +	read.fd = fd;
> +	read.memp = memp;
> +	read.len = len;
> +
> +	ret = smh_trap(SYSREAD, &read);
> +	if (ret < 0)
> +		return smh_errno();
> +	return len - ret;
> +}
> +
> +long smh_write(long fd, const void *memp, size_t len, ulong *written)
> +{
> +	long ret;
> +	struct smh_rdwr_s write;
> +
> +	debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
> +
> +	write.fd = fd;
> +	write.memp = (void *)memp;
> +	write.len = len;
> +
> +	ret = smh_trap(SYSWRITE, &write);
> +	*written = len - ret;
> +	if (ret)
> +		return smh_errno();
> +	return 0;
> +}
> +
> +long smh_close(long fd)
> +{
> +	long ret;
> +
> +	debug("%s: fd %ld\n", __func__, fd);
> +
> +	ret = smh_trap(SYSCLOSE, &fd);
> +	if (ret == -1)
> +		return smh_errno();
> +	return 0;
> +}
> +
> +long smh_flen(long fd)
> +{
> +	long ret;
> +
> +	debug("%s: fd %ld\n", __func__, fd);
> +
> +	ret = smh_trap(SYSFLEN, &fd);
> +	if (ret == -1)
> +		return smh_errno();
> +	return ret;
> +}
> +
> +long smh_seek(long fd, long pos)
> +{
> +	long ret;
> +	struct smh_seek_s {
> +		long fd;
> +		long pos;
> +	} seek;
> +
> +	debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
> +
> +	seek.fd = fd;
> +	seek.pos = pos;
> +
> +	ret = smh_trap(SYSSEEK, &seek);
> +	if (ret)
> +		return smh_errno();
> +	return 0;
> +}
> +
> +int smh_getc(void)
> +{
> +	return smh_trap(SYSREADC, NULL);
> +}
> +
> +void smh_putc(char ch)
> +{
> +	smh_trap(SYSWRITEC, &ch);
> +}
> +
> +void smh_puts(const char *s)
> +{
> +	smh_trap(SYSWRITE0, (char *)s);
> +}
> 

Reviewed-by: Sean Anderson <sean.anderson@seco.com>

Re: [PATCH v5 2/3] arch/riscv: add semihosting support for RISC-V

[Sean Anderson]

On 9/23/22 3:03 AM, Kautuk Consul wrote:
> We add RISC-V semihosting based serial console for JTAG based early
> debugging.
> 
> The RISC-V semihosting specification is available at:
> https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  arch/riscv/include/asm/spl.h |  1 +
>  arch/riscv/lib/Makefile      |  2 ++
>  arch/riscv/lib/interrupts.c  | 25 +++++++++++++++++++++++++
>  arch/riscv/lib/semihosting.c | 24 ++++++++++++++++++++++++
>  lib/Kconfig                  | 10 +++++-----
>  5 files changed, 57 insertions(+), 5 deletions(-)
>  create mode 100644 arch/riscv/lib/semihosting.c
> 
> diff --git a/arch/riscv/include/asm/spl.h b/arch/riscv/include/asm/spl.h
> index e8a94fcb1f..2898a770ee 100644
> --- a/arch/riscv/include/asm/spl.h
> +++ b/arch/riscv/include/asm/spl.h
> @@ -25,6 +25,7 @@ enum {
>  	BOOT_DEVICE_DFU,
>  	BOOT_DEVICE_XIP,
>  	BOOT_DEVICE_BOOTROM,
> +	BOOT_DEVICE_SMH,
>  	BOOT_DEVICE_NONE
>  };
>  
> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
> index 06020fcc2a..64e29804c1 100644
> --- a/arch/riscv/lib/Makefile
> +++ b/arch/riscv/lib/Makefile
> @@ -42,3 +42,5 @@ extra-$(CONFIG_EFI) += $(EFI_CRT0) $(EFI_RELOC)
>  obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMSET) += memset.o
>  obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMMOVE) += memmove.o
>  obj-$(CONFIG_$(SPL_TPL_)USE_ARCH_MEMCPY) += memcpy.o
> +
> +obj-$(CONFIG_$(SPL_TPL_)SEMIHOSTING) += semihosting.o
> diff --git a/arch/riscv/lib/interrupts.c b/arch/riscv/lib/interrupts.c
> index 100be2e966..e966afa7e3 100644
> --- a/arch/riscv/lib/interrupts.c
> +++ b/arch/riscv/lib/interrupts.c
> @@ -9,6 +9,7 @@
>   * Copyright (C) 2019 Sean Anderson <seanga2@gmail.com>
>   */
>  
> +#include <linux/compat.h>
>  #include <common.h>
>  #include <efi_loader.h>
>  #include <hang.h>
> @@ -17,6 +18,7 @@
>  #include <asm/ptrace.h>
>  #include <asm/system.h>
>  #include <asm/encoding.h>
> +#include <semihosting.h>
>  
>  DECLARE_GLOBAL_DATA_PTR;
>  
> @@ -149,6 +151,29 @@ ulong handle_trap(ulong cause, ulong epc, ulong tval, struct pt_regs *regs)
>  	/* An UEFI application may have changed gd. Restore U-Boot's gd. */
>  	efi_restore_gd();
>  
> +	if (cause == CAUSE_BREAKPOINT &&
> +	    CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)) {
> +		ulong pre_addr = epc - 4, post_addr = epc + 4;
> +
> +		/* Check for prior and post addresses to be in same page. */
> +		if ((pre_addr & ~(PAGE_SIZE - 1)) ==
> +			(post_addr & ~(PAGE_SIZE - 1))) {
> +			u32 pre = *(u32 *)pre_addr;
> +			u32 post = *(u32 *)post_addr;
> +
> +			/* Check for semihosting, i.e.:
> +			 * slli    zero,zero,0x1f
> +			 * ebreak
> +			 * srai    zero,zero,0x7
> +			 */
> +			if (pre == 0x01f01013 && post == 0x40705013) {
> +				disable_semihosting();
> +				epc += 4;
> +				return epc;
> +			}
> +		}
> +	}
> +
>  	is_irq = (cause & MCAUSE_INT);
>  	irq = (cause & ~MCAUSE_INT);
>  
> diff --git a/arch/riscv/lib/semihosting.c b/arch/riscv/lib/semihosting.c
> new file mode 100644
> index 0000000000..d6593b02a6
> --- /dev/null
> +++ b/arch/riscv/lib/semihosting.c
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <common.h>
> +
> +long smh_trap(int sysnum, void *addr)
> +{
> +	register int ret asm ("a0") = sysnum;
> +	register void *param0 asm ("a1") = addr;
> +
> +	asm volatile (".align 4\n"
> +		".option push\n"
> +		".option norvc\n"
> +
> +		"slli zero, zero, 0x1f\n"
> +		"ebreak\n"
> +		"srai zero, zero, 7\n"
> +		".option pop\n"
> +		: "+r" (ret) : "r" (param0) : "memory");
> +
> +	return ret;
> +}
> diff --git a/lib/Kconfig b/lib/Kconfig
> index de7e797f11..2cc556ee8a 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -73,7 +73,7 @@ config LIB_UUID
>  
>  config SEMIHOSTING
>  	bool "Support semihosting"
> -	depends on ARM
> +	depends on ARM || RISCV
>  	help
>  	  Semihosting is a method for a target to communicate with a host
>  	  debugger. It uses special instructions which the debugger will trap
> @@ -86,7 +86,7 @@ config SEMIHOSTING
>  
>  config SEMIHOSTING_FALLBACK
>  	bool "Recover gracefully when semihosting fails"
> -	depends on SEMIHOSTING && ARM64
> +	depends on SEMIHOSTING && (ARM64 || RISCV)
>  	default y
>  	help
>  	  Normally, if U-Boot makes a semihosting call and no debugger is
> @@ -96,7 +96,7 @@ config SEMIHOSTING_FALLBACK
>  
>  config SPL_SEMIHOSTING
>  	bool "Support semihosting in SPL"
> -	depends on SPL && ARM
> +	depends on SPL && (ARM || RISCV)
>  	help
>  	  Semihosting is a method for a target to communicate with a host
>  	  debugger. It uses special instructions which the debugger will trap
> @@ -109,8 +109,8 @@ config SPL_SEMIHOSTING
>  
>  config SPL_SEMIHOSTING_FALLBACK
>  	bool "Recover gracefully when semihosting fails in SPL"
> -	depends on SPL_SEMIHOSTING && ARM64
> -	select ARMV8_SPL_EXCEPTION_VECTORS
> +	depends on SPL_SEMIHOSTING && (ARM64 || RISCV)
> +	select ARMV8_SPL_EXCEPTION_VECTORS if ARM64
>  	default y
>  	help
>  	  Normally, if U-Boot makes a semihosting call and no debugger is
> 

Reviewed-by: Sean Anderson <sean.anderson@seco.com>

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Rick Chen]

> From: Kautuk Consul <kconsul@ventanamicro.com>
> Sent: Friday, September 23, 2022 3:03 PM
> To: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>; Sean Anderson <sean.anderson@seco.com>; Rick Jian-Zhi Chen(陳建志) <rick@andestech.com>; Leo Yu-Chi Liang(梁育齊) <ycliang@andestech.com>; Bin Meng <bmeng.cn@gmail.com>; Simon Glass <sjg@chromium.org>; Ilias Apalodimas <ilias.apalodimas@linaro.org>; Alexandru Gagniuc <mr.nuke.me@gmail.com>; Philippe Reynes <philippe.reynes@softathome.com>; Heinrich Schuchardt <xypron.glpk@gmx.de>; Rasmus Villemoes <rasmus.villemoes@prevas.dk>; Eugen Hristev <eugen.hristev@microchip.com>; Stefan Roese <sr@denx.de>; Loic Poulain <loic.poulain@linaro.org>; Peng Fan <peng.fan@nxp.com>; Michal Simek <michal.simek@amd.com>
> Cc: u-boot@lists.denx.de; Kautuk Consul <kconsul@ventanamicro.com>
> Subject: [PATCH v5 3/3] board: qemu-riscv: enable semihosting
>
> To enable semihosting we also need to enable the following configs in defconfigs:
> CONFIG_SEMIHOSTING
> CONFIG_SPL_SEMIHOSTING
> CONFIG_SEMIHOSTING_SERIAL
> CONFIG_SERIAL_PROBE_ALL
> CONFIG_SPL_FS_EXT4
> CONFIG_SPL_FS_FAT
>
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  configs/qemu-riscv32_defconfig       | 4 ++++
>  configs/qemu-riscv32_smode_defconfig | 4 ++++
>  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
>  configs/qemu-riscv64_defconfig       | 4 ++++
>  configs/qemu-riscv64_smode_defconfig | 4 ++++
>  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
>  6 files changed, 30 insertions(+)

Reviewed-by: Rick Chen <rick@andestech.com>

Re: [PATCH v5 2/3] arch/riscv: add semihosting support for RISC-V

[Rick Chen]

> From: Kautuk Consul <kconsul@ventanamicro.com>
> Sent: Friday, September 23, 2022 3:03 PM
> To: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>; Sean Anderson <sean.anderson@seco.com>; Rick Jian-Zhi Chen(陳建志) <rick@andestech.com>; Leo Yu-Chi Liang(梁育齊) <ycliang@andestech.com>; Bin Meng <bmeng.cn@gmail.com>; Simon Glass <sjg@chromium.org>; Ilias Apalodimas <ilias.apalodimas@linaro.org>; Alexandru Gagniuc <mr.nuke.me@gmail.com>; Philippe Reynes <philippe.reynes@softathome.com>; Heinrich Schuchardt <xypron.glpk@gmx.de>; Rasmus Villemoes <rasmus.villemoes@prevas.dk>; Eugen Hristev <eugen.hristev@microchip.com>; Stefan Roese <sr@denx.de>; Loic Poulain <loic.poulain@linaro.org>; Peng Fan <peng.fan@nxp.com>; Michal Simek <michal.simek@amd.com>
> Cc: u-boot@lists.denx.de; Kautuk Consul <kconsul@ventanamicro.com>; Anup Patel <apatel@ventanamicro.com>
> Subject: [PATCH v5 2/3] arch/riscv: add semihosting support for RISC-V
>
> We add RISC-V semihosting based serial console for JTAG based early debugging.
>
> The RISC-V semihosting specification is available at:
> https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  arch/riscv/include/asm/spl.h |  1 +
>  arch/riscv/lib/Makefile      |  2 ++
>  arch/riscv/lib/interrupts.c  | 25 +++++++++++++++++++++++++  arch/riscv/lib/semihosting.c | 24 ++++++++++++++++++++++++
>  lib/Kconfig                  | 10 +++++-----
>  5 files changed, 57 insertions(+), 5 deletions(-)  create mode 100644 arch/riscv/lib/semihosting.c

Reviewed-by: Rick Chen <rick@andestech.com>

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Kautuk Consul]

Hi,

Can someone pick this patchset up ?

It has been reviewed and there has been no comment on this in recent days.

Thanks.

On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com>
wrote:

> Semihosting is a mechanism that enables code running on
> a target to communicate and use the Input/Output
> facilities on a host computer that is running a debugger.
> This patchset adds support for semihosting in u-boot
> for RISCV64 targets.
>
> CHANGES since v4:
> -       Check arch dependencies for SEMIHOSTING as well as SPL_SEMIHOSTING
>         config options as per Sean's comment.
> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
>         of the ebreak statement whether they are as per the RISCV
>         semihosting specification. Only then do a disable_semihosting
>         and epc += 4 and return.
>
> Compilation and test commands for SPL and S-mode configurations
> =================================================================
>
> U-Boot S-mode on QEMU virt
> ----------------------------
> // Compilation of S-mode u-boot
> ARCH=riscv
> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> make qemu-riscv64_smode_defconfig
> make
> // Run riscv 64-bit u-boot with opensbi on qemu
> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> u-boot/u-boot.bin
>
> U-Boot SPL on QEMU virt
> ------------------------
> // Compilation of u-boot-spl
> ARCH=riscv
> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> make qemu-riscv64_spl_defconfig
> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> // Run 64-bit u-boot-spl in qemu
> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> u-boot/spl/u-boot-spl.bin -device\
> loader,file=u-boot/u-boot.itb,addr=0x80200000
>
> Kautuk Consul (3):
>   lib: Add common semihosting library
>   arch/riscv: add semihosting support for RISC-V
>   board: qemu-riscv: enable semihosting
>
>  arch/arm/Kconfig                     |  46 -------
>  arch/arm/lib/semihosting.c           | 181 +-------------------------
>  arch/riscv/include/asm/spl.h         |   1 +
>  arch/riscv/lib/Makefile              |   2 +
>  arch/riscv/lib/interrupts.c          |  25 ++++
>  arch/riscv/lib/semihosting.c         |  24 ++++
>  configs/qemu-riscv32_defconfig       |   4 +
>  configs/qemu-riscv32_smode_defconfig |   4 +
>  configs/qemu-riscv32_spl_defconfig   |   7 +
>  configs/qemu-riscv64_defconfig       |   4 +
>  configs/qemu-riscv64_smode_defconfig |   4 +
>  configs/qemu-riscv64_spl_defconfig   |   7 +
>  include/semihosting.h                |  11 ++
>  lib/Kconfig                          |  47 +++++++
>  lib/Makefile                         |   2 +
>  lib/semihosting.c                    | 186 +++++++++++++++++++++++++++
>  16 files changed, 329 insertions(+), 226 deletions(-)
>  create mode 100644 arch/riscv/lib/semihosting.c
>  create mode 100644 lib/semihosting.c
>
> --
> 2.34.1
>
>

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Bin Meng]

Hi Kautuk,

On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>
> Hi,
>
> Can someone pick this patchset up ?
>
> It has been reviewed and there has been no comment on this in recent days.
>
> Thanks.
>
> On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>>
>> Semihosting is a mechanism that enables code running on
>> a target to communicate and use the Input/Output
>> facilities on a host computer that is running a debugger.
>> This patchset adds support for semihosting in u-boot
>> for RISCV64 targets.
>>
>> CHANGES since v4:
>> -       Check arch dependencies for SEMIHOSTING as well as SPL_SEMIHOSTING
>>         config options as per Sean's comment.
>> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
>>         of the ebreak statement whether they are as per the RISCV
>>         semihosting specification. Only then do a disable_semihosting
>>         and epc += 4 and return.
>>
>> Compilation and test commands for SPL and S-mode configurations
>> =================================================================
>>
>> U-Boot S-mode on QEMU virt
>> ----------------------------
>> // Compilation of S-mode u-boot
>> ARCH=riscv
>> CROSS_COMPILE=riscv64-unknown-linux-gnu-
>> make qemu-riscv64_smode_defconfig
>> make
>> // Run riscv 64-bit u-boot with opensbi on qemu
>> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
>> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
>> u-boot/u-boot.bin
>>
>> U-Boot SPL on QEMU virt
>> ------------------------
>> // Compilation of u-boot-spl
>> ARCH=riscv
>> CROSS_COMPILE=riscv64-unknown-linux-gnu-
>> make qemu-riscv64_spl_defconfig
>> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
>> // Run 64-bit u-boot-spl in qemu
>> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
>> u-boot/spl/u-boot-spl.bin -device\
>> loader,file=u-boot/u-boot.itb,addr=0x80200000
>>

Do you have instructions on how to actually test semihosting? Does it
require a JTAG debugger? But I see you are using QEMU?

Regards,
Bin

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Kautuk Consul]

I have tested it both on Qemu and Ventana's internal simulator.

On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:

> Hi Kautuk,
>
> On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <kconsul@ventanamicro.com>
> wrote:
> >
> > Hi,
> >
> > Can someone pick this patchset up ?
> >
> > It has been reviewed and there has been no comment on this in recent
> days.
> >
> > Thanks.
> >
> > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com>
> wrote:
> >>
> >> Semihosting is a mechanism that enables code running on
> >> a target to communicate and use the Input/Output
> >> facilities on a host computer that is running a debugger.
> >> This patchset adds support for semihosting in u-boot
> >> for RISCV64 targets.
> >>
> >> CHANGES since v4:
> >> -       Check arch dependencies for SEMIHOSTING as well as
> SPL_SEMIHOSTING
> >>         config options as per Sean's comment.
> >> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
> >>         of the ebreak statement whether they are as per the RISCV
> >>         semihosting specification. Only then do a disable_semihosting
> >>         and epc += 4 and return.
> >>
> >> Compilation and test commands for SPL and S-mode configurations
> >> =================================================================
> >>
> >> U-Boot S-mode on QEMU virt
> >> ----------------------------
> >> // Compilation of S-mode u-boot
> >> ARCH=riscv
> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> >> make qemu-riscv64_smode_defconfig
> >> make
> >> // Run riscv 64-bit u-boot with opensbi on qemu
> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> >> u-boot/u-boot.bin
> >>
> >> U-Boot SPL on QEMU virt
> >> ------------------------
> >> // Compilation of u-boot-spl
> >> ARCH=riscv
> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> >> make qemu-riscv64_spl_defconfig
> >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> >> // Run 64-bit u-boot-spl in qemu
> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> >> u-boot/spl/u-boot-spl.bin -device\
> >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> >>
>
> Do you have instructions on how to actually test semihosting? Does it
> require a JTAG debugger? But I see you are using QEMU?
>
> Regards,
> Bin
>

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Leo Liang]

Hi Kautuk,

Sorry for the late reply.
The CI failure still exists and
if tested on QEMU(7.0.0) without a gdb attached,
it is possible that we get weird output on console.[1]

Another thing is that with your patch,
QEMU could not exit with Ctrl a + x.
This might be the reason for CI failure (timeout).
Could you take a look at this?

Yet with a gdb attached, everything works as expected,
So maybe we could disable semihosting as default?

Best regards,
Leo

[1] The weird console output looks like below, 
it outputs random character without us typing anything. 

U-Boot 2022.10-rc5 (Dec 02 2022 - 16:27:43 +0800)
CPU:   rv64imafdcsuh
Model: riscv-virtio,qemu
DRAM:  2 GiB
Core:  35 devices, 15 uclasses, devicetree: board
Flash: 32 MiB
Loading Environment from nowhere... OK
In:    serial_semihosting
Out:   serial_semihosting
Err:   serial_semihosting
Net:   eth0: virtio-net#1
Hit any key to stop autoboot:  0
=> 55555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555
55555555555555555555555555555555555555555555555555555555555555555555



On Tue, Nov 29, 2022 at 12:27:51PM +0530, Kautuk Consul wrote:
> I have tested it both on Qemu and Ventana's internal simulator.
> 
> On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> 
> > Hi Kautuk,
> >
> > On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <kconsul@ventanamicro.com>
> > wrote:
> > >
> > > Hi,
> > >
> > > Can someone pick this patchset up ?
> > >
> > > It has been reviewed and there has been no comment on this in recent
> > days.
> > >
> > > Thanks.
> > >
> > > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com>
> > wrote:
> > >>
> > >> Semihosting is a mechanism that enables code running on
> > >> a target to communicate and use the Input/Output
> > >> facilities on a host computer that is running a debugger.
> > >> This patchset adds support for semihosting in u-boot
> > >> for RISCV64 targets.
> > >>
> > >> CHANGES since v4:
> > >> -       Check arch dependencies for SEMIHOSTING as well as
> > SPL_SEMIHOSTING
> > >>         config options as per Sean's comment.
> > >> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
> > >>         of the ebreak statement whether they are as per the RISCV
> > >>         semihosting specification. Only then do a disable_semihosting
> > >>         and epc += 4 and return.
> > >>
> > >> Compilation and test commands for SPL and S-mode configurations
> > >> =================================================================
> > >>
> > >> U-Boot S-mode on QEMU virt
> > >> ----------------------------
> > >> // Compilation of S-mode u-boot
> > >> ARCH=riscv
> > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > >> make qemu-riscv64_smode_defconfig
> > >> make
> > >> // Run riscv 64-bit u-boot with opensbi on qemu
> > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> > >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> > >> u-boot/u-boot.bin
> > >>
> > >> U-Boot SPL on QEMU virt
> > >> ------------------------
> > >> // Compilation of u-boot-spl
> > >> ARCH=riscv
> > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > >> make qemu-riscv64_spl_defconfig
> > >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> > >> // Run 64-bit u-boot-spl in qemu
> > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> > >> u-boot/spl/u-boot-spl.bin -device\
> > >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> > >>
> >
> > Do you have instructions on how to actually test semihosting? Does it
> > require a JTAG debugger? But I see you are using QEMU?
> >
> > Regards,
> > Bin
> >

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Kautuk Consul]

Hi Leo,

What Qemu version are you using.
Can you please try with QEMU 7.1 or later ?
There is a fix which was merged after 7.0.

Thanks.

On Fri, Dec 2, 2022 at 2:16 PM Leo Liang <ycliang@andestech.com> wrote:

> Hi Kautuk,
>
> Sorry for the late reply.
> The CI failure still exists and
> if tested on QEMU(7.0.0) without a gdb attached,
> it is possible that we get weird output on console.[1]
>
> Another thing is that with your patch,
> QEMU could not exit with Ctrl a + x.
> This might be the reason for CI failure (timeout).
> Could you take a look at this?
>
> Yet with a gdb attached, everything works as expected,
> So maybe we could disable semihosting as default?
>
> Best regards,
> Leo
>
> [1] The weird console output looks like below,
> it outputs random character without us typing anything.
>
> U-Boot 2022.10-rc5 (Dec 02 2022 - 16:27:43 +0800)
> CPU:   rv64imafdcsuh
> Model: riscv-virtio,qemu
> DRAM:  2 GiB
> Core:  35 devices, 15 uclasses, devicetree: board
> Flash: 32 MiB
> Loading Environment from nowhere... OK
> In:    serial_semihosting
> Out:   serial_semihosting
> Err:   serial_semihosting
> Net:   eth0: virtio-net#1
> Hit any key to stop autoboot:  0
> =>
> 55555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555
> 55555555555555555555555555555555555555555555555555555555555555555555
>
>
>
> On Tue, Nov 29, 2022 at 12:27:51PM +0530, Kautuk Consul wrote:
> > I have tested it both on Qemu and Ventana's internal simulator.
> >
> > On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > > Hi Kautuk,
> > >
> > > On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <
> kconsul@ventanamicro.com>
> > > wrote:
> > > >
> > > > Hi,
> > > >
> > > > Can someone pick this patchset up ?
> > > >
> > > > It has been reviewed and there has been no comment on this in recent
> > > days.
> > > >
> > > > Thanks.
> > > >
> > > > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <
> kconsul@ventanamicro.com>
> > > wrote:
> > > >>
> > > >> Semihosting is a mechanism that enables code running on
> > > >> a target to communicate and use the Input/Output
> > > >> facilities on a host computer that is running a debugger.
> > > >> This patchset adds support for semihosting in u-boot
> > > >> for RISCV64 targets.
> > > >>
> > > >> CHANGES since v4:
> > > >> -       Check arch dependencies for SEMIHOSTING as well as
> > > SPL_SEMIHOSTING
> > > >>         config options as per Sean's comment.
> > > >> -       arch/riscv/lib/interrupts.c: Check for post and pre
> instructions
> > > >>         of the ebreak statement whether they are as per the RISCV
> > > >>         semihosting specification. Only then do a
> disable_semihosting
> > > >>         and epc += 4 and return.
> > > >>
> > > >> Compilation and test commands for SPL and S-mode configurations
> > > >> =================================================================
> > > >>
> > > >> U-Boot S-mode on QEMU virt
> > > >> ----------------------------
> > > >> // Compilation of S-mode u-boot
> > > >> ARCH=riscv
> > > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > > >> make qemu-riscv64_smode_defconfig
> > > >> make
> > > >> // Run riscv 64-bit u-boot with opensbi on qemu
> > > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> -bios\
> > > >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> > > >> u-boot/u-boot.bin
> > > >>
> > > >> U-Boot SPL on QEMU virt
> > > >> ------------------------
> > > >> // Compilation of u-boot-spl
> > > >> ARCH=riscv
> > > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > > >> make qemu-riscv64_spl_defconfig
> > > >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> > > >> // Run 64-bit u-boot-spl in qemu
> > > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> -bios\
> > > >> u-boot/spl/u-boot-spl.bin -device\
> > > >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> > > >>
> > >
> > > Do you have instructions on how to actually test semihosting? Does it
> > > require a JTAG debugger? But I see you are using QEMU?
> > >
> > > Regards,
> > > Bin
> > >
>

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Leo Liang]

Hi Kautuk,

On Fri, Dec 02, 2022 at 03:22:56PM +0530, Kautuk Consul wrote:
> Hi Leo,
> 
> What Qemu version are you using.
> Can you please try with QEMU 7.1 or later ?
> There is a fix which was merged after 7.0.

Got it! 
I'll try with QEMU 7.1 and see if the issue still exists.
Thanks!

Best regards,
Leo

> 
> Thanks.
> 
> On Fri, Dec 2, 2022 at 2:16 PM Leo Liang <ycliang@andestech.com> wrote:
> 
> > Hi Kautuk,
> >
> > Sorry for the late reply.
> > The CI failure still exists and
> > if tested on QEMU(7.0.0) without a gdb attached,
> > it is possible that we get weird output on console.[1]
> >
> > Another thing is that with your patch,
> > QEMU could not exit with Ctrl a + x.
> > This might be the reason for CI failure (timeout).
> > Could you take a look at this?
> >
> > Yet with a gdb attached, everything works as expected,
> > So maybe we could disable semihosting as default?
> >
> > Best regards,
> > Leo
> >
> > [1] The weird console output looks like below,
> > it outputs random character without us typing anything.
> >
> > U-Boot 2022.10-rc5 (Dec 02 2022 - 16:27:43 +0800)
> > CPU:   rv64imafdcsuh
> > Model: riscv-virtio,qemu
> > DRAM:  2 GiB
> > Core:  35 devices, 15 uclasses, devicetree: board
> > Flash: 32 MiB
> > Loading Environment from nowhere... OK
> > In:    serial_semihosting
> > Out:   serial_semihosting
> > Err:   serial_semihosting
> > Net:   eth0: virtio-net#1
> > Hit any key to stop autoboot:  0
> > =>
> > 55555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555
> > 55555555555555555555555555555555555555555555555555555555555555555555
> >
> >
> >
> > On Tue, Nov 29, 2022 at 12:27:51PM +0530, Kautuk Consul wrote:
> > > I have tested it both on Qemu and Ventana's internal simulator.
> > >
> > > On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> > >
> > > > Hi Kautuk,
> > > >
> > > > On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <
> > kconsul@ventanamicro.com>
> > > > wrote:
> > > > >
> > > > > Hi,
> > > > >
> > > > > Can someone pick this patchset up ?
> > > > >
> > > > > It has been reviewed and there has been no comment on this in recent
> > > > days.
> > > > >
> > > > > Thanks.
> > > > >
> > > > > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <
> > kconsul@ventanamicro.com>
> > > > wrote:
> > > > >>
> > > > >> Semihosting is a mechanism that enables code running on
> > > > >> a target to communicate and use the Input/Output
> > > > >> facilities on a host computer that is running a debugger.
> > > > >> This patchset adds support for semihosting in u-boot
> > > > >> for RISCV64 targets.
> > > > >>
> > > > >> CHANGES since v4:
> > > > >> -       Check arch dependencies for SEMIHOSTING as well as
> > > > SPL_SEMIHOSTING
> > > > >>         config options as per Sean's comment.
> > > > >> -       arch/riscv/lib/interrupts.c: Check for post and pre
> > instructions
> > > > >>         of the ebreak statement whether they are as per the RISCV
> > > > >>         semihosting specification. Only then do a
> > disable_semihosting
> > > > >>         and epc += 4 and return.
> > > > >>
> > > > >> Compilation and test commands for SPL and S-mode configurations
> > > > >> =================================================================
> > > > >>
> > > > >> U-Boot S-mode on QEMU virt
> > > > >> ----------------------------
> > > > >> // Compilation of S-mode u-boot
> > > > >> ARCH=riscv
> > > > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > > > >> make qemu-riscv64_smode_defconfig
> > > > >> make
> > > > >> // Run riscv 64-bit u-boot with opensbi on qemu
> > > > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> > -bios\
> > > > >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> > > > >> u-boot/u-boot.bin
> > > > >>
> > > > >> U-Boot SPL on QEMU virt
> > > > >> ------------------------
> > > > >> // Compilation of u-boot-spl
> > > > >> ARCH=riscv
> > > > >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > > > >> make qemu-riscv64_spl_defconfig
> > > > >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> > > > >> // Run 64-bit u-boot-spl in qemu
> > > > >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> > -bios\
> > > > >> u-boot/spl/u-boot-spl.bin -device\
> > > > >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> > > > >>
> > > >
> > > > Do you have instructions on how to actually test semihosting? Does it
> > > > require a JTAG debugger? But I see you are using QEMU?
> > > >
> > > > Regards,
> > > > Bin
> > > >
> >

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Bin Meng]

On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>
> To enable semihosting we also need to enable the following
> configs in defconfigs:
> CONFIG_SEMIHOSTING
> CONFIG_SPL_SEMIHOSTING
> CONFIG_SEMIHOSTING_SERIAL
> CONFIG_SERIAL_PROBE_ALL
> CONFIG_SPL_FS_EXT4
> CONFIG_SPL_FS_FAT

Why should these _SPL_FS_xxx be required? If it's required by
SEMIHOSTING, could the dependency be fixed there?

>
> Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> ---
>  configs/qemu-riscv32_defconfig       | 4 ++++
>  configs/qemu-riscv32_smode_defconfig | 4 ++++
>  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
>  configs/qemu-riscv64_defconfig       | 4 ++++
>  configs/qemu-riscv64_smode_defconfig | 4 ++++
>  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
>  6 files changed, 30 insertions(+)
>

Regards,
Bin

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Bin Meng]

On Tue, Nov 29, 2022 at 2:58 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>
> I have tested it both on Qemu and Ventana's internal simulator.

How to verify this? I used your instructions and U-Boot says: No match
for driver 'serial_semihosting'

U-Boot 2023.01-rc2-00113-g2a4accaf5e (Dec 03 2022 - 12:20:20 +0800)
CPU: rv64imafdch_zicsr_zifencei_zihintpause_zba_zbb_zbc_zbs_sstc
Model: riscv-virtio,qemu
DRAM: 256 MiB
No match for driver 'serial_semihosting'
Some drivers were not found
Core: 25 devices, 12 uclasses, devicetree: board
Flash: 32 MiB
Loading Environment from nowhere... OK
In: serial@10000000
Out: serial@10000000
Err: serial@10000000
Net: No ethernet found.
Working FDT set to 8f734950
Hit any key to stop autoboot: 0
=>

>
> On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>>
>> Hi Kautuk,
>>
>> On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>> >
>> > Hi,
>> >
>> > Can someone pick this patchset up ?
>> >
>> > It has been reviewed and there has been no comment on this in recent days.
>> >
>> > Thanks.
>> >
>> > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>> >>
>> >> Semihosting is a mechanism that enables code running on
>> >> a target to communicate and use the Input/Output
>> >> facilities on a host computer that is running a debugger.
>> >> This patchset adds support for semihosting in u-boot
>> >> for RISCV64 targets.
>> >>
>> >> CHANGES since v4:
>> >> -       Check arch dependencies for SEMIHOSTING as well as SPL_SEMIHOSTING
>> >>         config options as per Sean's comment.
>> >> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
>> >>         of the ebreak statement whether they are as per the RISCV
>> >>         semihosting specification. Only then do a disable_semihosting
>> >>         and epc += 4 and return.
>> >>
>> >> Compilation and test commands for SPL and S-mode configurations
>> >> =================================================================
>> >>
>> >> U-Boot S-mode on QEMU virt
>> >> ----------------------------
>> >> // Compilation of S-mode u-boot
>> >> ARCH=riscv
>> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
>> >> make qemu-riscv64_smode_defconfig
>> >> make
>> >> // Run riscv 64-bit u-boot with opensbi on qemu
>> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
>> >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
>> >> u-boot/u-boot.bin
>> >>
>> >> U-Boot SPL on QEMU virt
>> >> ------------------------
>> >> // Compilation of u-boot-spl
>> >> ARCH=riscv
>> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
>> >> make qemu-riscv64_spl_defconfig
>> >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
>> >> // Run 64-bit u-boot-spl in qemu
>> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
>> >> u-boot/spl/u-boot-spl.bin -device\
>> >> loader,file=u-boot/u-boot.itb,addr=0x80200000
>> >>
>>
>> Do you have instructions on how to actually test semihosting? Does it
>> require a JTAG debugger? But I see you are using QEMU?
>>

Regards,
Bin

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Bin Meng]

Hi Kautuk,

On Sat, Dec 3, 2022 at 12:28 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Tue, Nov 29, 2022 at 2:58 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> >
> > I have tested it both on Qemu and Ventana's internal simulator.
>
> How to verify this? I used your instructions and U-Boot says: No match
> for driver 'serial_semihosting'
>
> U-Boot 2023.01-rc2-00113-g2a4accaf5e (Dec 03 2022 - 12:20:20 +0800)
> CPU: rv64imafdch_zicsr_zifencei_zihintpause_zba_zbb_zbc_zbs_sstc
> Model: riscv-virtio,qemu
> DRAM: 256 MiB
> No match for driver 'serial_semihosting'
> Some drivers were not found
> Core: 25 devices, 12 uclasses, devicetree: board
> Flash: 32 MiB
> Loading Environment from nowhere... OK
> In: serial@10000000
> Out: serial@10000000
> Err: serial@10000000
> Net: No ethernet found.
> Working FDT set to 8f734950
> Hit any key to stop autoboot: 0
> =>
>
> >
> > On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> >>
> >> Hi Kautuk,
> >>
> >> On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> >> >
> >> > Hi,
> >> >
> >> > Can someone pick this patchset up ?
> >> >
> >> > It has been reviewed and there has been no comment on this in recent days.
> >> >
> >> > Thanks.
> >> >
> >> > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> >> >>
> >> >> Semihosting is a mechanism that enables code running on
> >> >> a target to communicate and use the Input/Output
> >> >> facilities on a host computer that is running a debugger.
> >> >> This patchset adds support for semihosting in u-boot
> >> >> for RISCV64 targets.
> >> >>
> >> >> CHANGES since v4:
> >> >> -       Check arch dependencies for SEMIHOSTING as well as SPL_SEMIHOSTING
> >> >>         config options as per Sean's comment.
> >> >> -       arch/riscv/lib/interrupts.c: Check for post and pre instructions
> >> >>         of the ebreak statement whether they are as per the RISCV
> >> >>         semihosting specification. Only then do a disable_semihosting
> >> >>         and epc += 4 and return.
> >> >>
> >> >> Compilation and test commands for SPL and S-mode configurations
> >> >> =================================================================
> >> >>
> >> >> U-Boot S-mode on QEMU virt
> >> >> ----------------------------
> >> >> // Compilation of S-mode u-boot
> >> >> ARCH=riscv
> >> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> >> >> make qemu-riscv64_smode_defconfig
> >> >> make
> >> >> // Run riscv 64-bit u-boot with opensbi on qemu
> >> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> >> >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> >> >> u-boot/u-boot.bin

It turns out your instructions missed "-semihosting" in the QEMU command line.

With that I can see U-Boot boots with the serial_semihosting driver.

> >> >>
> >> >> U-Boot SPL on QEMU virt
> >> >> ------------------------
> >> >> // Compilation of u-boot-spl
> >> >> ARCH=riscv
> >> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> >> >> make qemu-riscv64_spl_defconfig
> >> >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> >> >> // Run 64-bit u-boot-spl in qemu
> >> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio -bios\
> >> >> u-boot/spl/u-boot-spl.bin -device\
> >> >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> >> >>
> >>
> >> Do you have instructions on how to actually test semihosting? Does it
> >> require a JTAG debugger? But I see you are using QEMU?
> >>
>

Regards,
Bin

Re: [PATCH v5 0/3] Add riscv semihosting support in u-boot

[Kautuk Consul]

Sorry about that! I assumed everyone would know the option and decided to
just upt the ordinary command
to show that the semihosting changes don't impact the non-semihosting
scenarios.

On Sat, Dec 3, 2022 at 11:32 AM Bin Meng <bmeng.cn@gmail.com> wrote:

> Hi Kautuk,
>
> On Sat, Dec 3, 2022 at 12:28 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > On Tue, Nov 29, 2022 at 2:58 PM Kautuk Consul <kconsul@ventanamicro.com>
> wrote:
> > >
> > > I have tested it both on Qemu and Ventana's internal simulator.
> >
> > How to verify this? I used your instructions and U-Boot says: No match
> > for driver 'serial_semihosting'
> >
> > U-Boot 2023.01-rc2-00113-g2a4accaf5e (Dec 03 2022 - 12:20:20 +0800)
> > CPU: rv64imafdch_zicsr_zifencei_zihintpause_zba_zbb_zbc_zbs_sstc
> > Model: riscv-virtio,qemu
> > DRAM: 256 MiB
> > No match for driver 'serial_semihosting'
> > Some drivers were not found
> > Core: 25 devices, 12 uclasses, devicetree: board
> > Flash: 32 MiB
> > Loading Environment from nowhere... OK
> > In: serial@10000000
> > Out: serial@10000000
> > Err: serial@10000000
> > Net: No ethernet found.
> > Working FDT set to 8f734950
> > Hit any key to stop autoboot: 0
> > =>
> >
> > >
> > > On Tue, Nov 29, 2022 at 12:06 PM Bin Meng <bmeng.cn@gmail.com> wrote:
> > >>
> > >> Hi Kautuk,
> > >>
> > >> On Tue, Nov 29, 2022 at 2:29 PM Kautuk Consul <
> kconsul@ventanamicro.com> wrote:
> > >> >
> > >> > Hi,
> > >> >
> > >> > Can someone pick this patchset up ?
> > >> >
> > >> > It has been reviewed and there has been no comment on this in
> recent days.
> > >> >
> > >> > Thanks.
> > >> >
> > >> > On Fri, Sep 23, 2022 at 12:33 PM Kautuk Consul <
> kconsul@ventanamicro.com> wrote:
> > >> >>
> > >> >> Semihosting is a mechanism that enables code running on
> > >> >> a target to communicate and use the Input/Output
> > >> >> facilities on a host computer that is running a debugger.
> > >> >> This patchset adds support for semihosting in u-boot
> > >> >> for RISCV64 targets.
> > >> >>
> > >> >> CHANGES since v4:
> > >> >> -       Check arch dependencies for SEMIHOSTING as well as
> SPL_SEMIHOSTING
> > >> >>         config options as per Sean's comment.
> > >> >> -       arch/riscv/lib/interrupts.c: Check for post and pre
> instructions
> > >> >>         of the ebreak statement whether they are as per the RISCV
> > >> >>         semihosting specification. Only then do a
> disable_semihosting
> > >> >>         and epc += 4 and return.
> > >> >>
> > >> >> Compilation and test commands for SPL and S-mode configurations
> > >> >> =================================================================
> > >> >>
> > >> >> U-Boot S-mode on QEMU virt
> > >> >> ----------------------------
> > >> >> // Compilation of S-mode u-boot
> > >> >> ARCH=riscv
> > >> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > >> >> make qemu-riscv64_smode_defconfig
> > >> >> make
> > >> >> // Run riscv 64-bit u-boot with opensbi on qemu
> > >> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> -bios\
> > >> >> opensbi/build/platform/generic/firmware/fw_jump.bin -kernel\
> > >> >> u-boot/u-boot.bin
>
> It turns out your instructions missed "-semihosting" in the QEMU command
> line.
>
> With that I can see U-Boot boots with the serial_semihosting driver.
>
> > >> >>
> > >> >> U-Boot SPL on QEMU virt
> > >> >> ------------------------
> > >> >> // Compilation of u-boot-spl
> > >> >> ARCH=riscv
> > >> >> CROSS_COMPILE=riscv64-unknown-linux-gnu-
> > >> >> make qemu-riscv64_spl_defconfig
> > >> >> make OPENSBI=opensbi/build/platform/generic/firmware/fw_dynamic.bin
> > >> >> // Run 64-bit u-boot-spl in qemu
> > >> >> qemu-system-riscv64 -M virt -m 256M -display none -serial stdio
> -bios\
> > >> >> u-boot/spl/u-boot-spl.bin -device\
> > >> >> loader,file=u-boot/u-boot.itb,addr=0x80200000
> > >> >>
> > >>
> > >> Do you have instructions on how to actually test semihosting? Does it
> > >> require a JTAG debugger? But I see you are using QEMU?
> > >>
> >
>
> Regards,
> Bin
>

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

Hi,

On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> >
> > To enable semihosting we also need to enable the following
> > configs in defconfigs:
> > CONFIG_SEMIHOSTING
> > CONFIG_SPL_SEMIHOSTING
> > CONFIG_SEMIHOSTING_SERIAL
> > CONFIG_SERIAL_PROBE_ALL
> > CONFIG_SPL_FS_EXT4
> > CONFIG_SPL_FS_FAT
>
> Why should these _SPL_FS_xxx be required? If it's required by
> SEMIHOSTING, could the dependency be fixed there?

The build dependencies require that these options be there.

>
> >
> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > ---
> >  configs/qemu-riscv32_defconfig       | 4 ++++
> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> >  configs/qemu-riscv64_defconfig       | 4 ++++
> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> >  6 files changed, 30 insertions(+)
> >
>
> Regards,
> Bin

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Bin Meng]

On Mon, Dec 5, 2022 at 1:51 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>
> Hi,
>
> On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> > >
> > > To enable semihosting we also need to enable the following
> > > configs in defconfigs:
> > > CONFIG_SEMIHOSTING
> > > CONFIG_SPL_SEMIHOSTING
> > > CONFIG_SEMIHOSTING_SERIAL
> > > CONFIG_SERIAL_PROBE_ALL
> > > CONFIG_SPL_FS_EXT4
> > > CONFIG_SPL_FS_FAT
> >
> > Why should these _SPL_FS_xxx be required? If it's required by
> > SEMIHOSTING, could the dependency be fixed there?
>
> The build dependencies require that these options be there.
>

I think you need to fix the dependencies of CONFIG_SPL_SEMIHOSTING

Regards,
Bin

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Sean Anderson]

On 12/5/22 00:51, Kautuk Consul wrote:
> Hi,
> 
> On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>>
>> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>> >
>> > To enable semihosting we also need to enable the following
>> > configs in defconfigs:
>> > CONFIG_SEMIHOSTING
>> > CONFIG_SPL_SEMIHOSTING
>> > CONFIG_SEMIHOSTING_SERIAL
>> > CONFIG_SERIAL_PROBE_ALL
>> > CONFIG_SPL_FS_EXT4
>> > CONFIG_SPL_FS_FAT
>>
>> Why should these _SPL_FS_xxx be required? If it's required by
>> SEMIHOSTING, could the dependency be fixed there?
> 
> The build dependencies require that these options be there.

What error do you get?

--Sean

>>
>> >
>> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
>> > ---
>> >  configs/qemu-riscv32_defconfig       | 4 ++++
>> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
>> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
>> >  configs/qemu-riscv64_defconfig       | 4 ++++
>> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
>> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
>> >  6 files changed, 30 insertions(+)
>> >
>>
>> Regards,
>> Bin

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

Hi,

On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
>
> On 12/5/22 00:51, Kautuk Consul wrote:
> > Hi,
> >
> > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> >>
> >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> >> >
> >> > To enable semihosting we also need to enable the following
> >> > configs in defconfigs:
> >> > CONFIG_SEMIHOSTING
> >> > CONFIG_SPL_SEMIHOSTING
> >> > CONFIG_SEMIHOSTING_SERIAL
> >> > CONFIG_SERIAL_PROBE_ALL
> >> > CONFIG_SPL_FS_EXT4
> >> > CONFIG_SPL_FS_FAT
> >>
> >> Why should these _SPL_FS_xxx be required? If it's required by
> >> SEMIHOSTING, could the dependency be fixed there?
> >
> > The build dependencies require that these options be there.
>
> What error do you get?

If I disable both the _SPL_FS_* config options then I get the
following compilation error:
common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
common/spl/spl_semihosting.c:27:32: error:
'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
function)
   27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
      |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
is reported only once for each function it appears in

Bin/Sean: This error is not really related to the semihosting feature
but is related to COFIG_SPL in general.
Can you please accept this patch-set and then I'll try and find time
in the future maybe to rectify this build dependency
problem ?

>
> --Sean
>
> >>
> >> >
> >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> >> > ---
> >> >  configs/qemu-riscv32_defconfig       | 4 ++++
> >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> >> >  configs/qemu-riscv64_defconfig       | 4 ++++
> >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> >> >  6 files changed, 30 insertions(+)
> >> >
> >>
> >> Regards,
> >> Bin
>

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Leo Liang]

Hi Kautuk,

We have tested your patchset with QEMU 7.1.0.
It generally looks fine, but CI error seems to persist.
https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/14314

The error comes from CI testcase timed-out.
The reason for the time-out is not yet confirmed, 
but we suspect it's because when executing under semihosting, 
QEMU could not exit normally. (thru ctrl+x a)

There is a seemingly relevent patchset that sits on QEMU mailing list for some time.
https://lore.kernel.org/all/20220620190834.GA16887@ws2101.lin.mbt.kalray.eu/T/#m1bc32cc32511b6ac8adfaf67983dc2bccd4b9ec9

On the u-boot side, what do you think if we disable semihosting by default?
(i.e., not adding CONFIG_SEMIHOSTING_XXX in qemu's defconfig)

Best regards,
Leo

On Tue, Dec 06, 2022 at 11:12:41AM +0530, Kautuk Consul wrote:
> Hi,
> 
> On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
> >
> > On 12/5/22 00:51, Kautuk Consul wrote:
> > > Hi,
> > >
> > > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> > >>
> > >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> > >> >
> > >> > To enable semihosting we also need to enable the following
> > >> > configs in defconfigs:
> > >> > CONFIG_SEMIHOSTING
> > >> > CONFIG_SPL_SEMIHOSTING
> > >> > CONFIG_SEMIHOSTING_SERIAL
> > >> > CONFIG_SERIAL_PROBE_ALL
> > >> > CONFIG_SPL_FS_EXT4
> > >> > CONFIG_SPL_FS_FAT
> > >>
> > >> Why should these _SPL_FS_xxx be required? If it's required by
> > >> SEMIHOSTING, could the dependency be fixed there?
> > >
> > > The build dependencies require that these options be there.
> >
> > What error do you get?
> 
> If I disable both the _SPL_FS_* config options then I get the
> following compilation error:
> common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
> common/spl/spl_semihosting.c:27:32: error:
> 'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
> function)
>    27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
>       |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
> is reported only once for each function it appears in
> 
> Bin/Sean: This error is not really related to the semihosting feature
> but is related to COFIG_SPL in general.
> Can you please accept this patch-set and then I'll try and find time
> in the future maybe to rectify this build dependency
> problem ?
> 
> >
> > --Sean
> >
> > >>
> > >> >
> > >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > >> > ---
> > >> >  configs/qemu-riscv32_defconfig       | 4 ++++
> > >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> > >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> > >> >  configs/qemu-riscv64_defconfig       | 4 ++++
> > >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> > >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> > >> >  6 files changed, 30 insertions(+)
> > >> >
> > >>
> > >> Regards,
> > >> Bin
> >

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

Hi Leo,

On Tue, Dec 6, 2022 at 4:29 PM Leo Liang <ycliang@andestech.com> wrote:
>
> Hi Kautuk,
>
> We have tested your patchset with QEMU 7.1.0.
> It generally looks fine, but CI error seems to persist.
> https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/14314
>
> The error comes from CI testcase timed-out.
> The reason for the time-out is not yet confirmed,
> but we suspect it's because when executing under semihosting,
> QEMU could not exit normally. (thru ctrl+x a)
>
> There is a seemingly relevent patchset that sits on QEMU mailing list for some time.
> https://lore.kernel.org/all/20220620190834.GA16887@ws2101.lin.mbt.kalray.eu/T/#m1bc32cc32511b6ac8adfaf67983dc2bccd4b9ec9
>
> On the u-boot side, what do you think if we disable semihosting by default?
> (i.e., not adding CONFIG_SEMIHOSTING_XXX in qemu's defconfig)

I think it is okay to disable semihosting by default. Then the user
will configure it when needed.
So then can you ACK the first 2 patches ? I think we can leave out the
3rd qemu config patch for now.

>
> Best regards,
> Leo
>
> On Tue, Dec 06, 2022 at 11:12:41AM +0530, Kautuk Consul wrote:
> > Hi,
> >
> > On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
> > >
> > > On 12/5/22 00:51, Kautuk Consul wrote:
> > > > Hi,
> > > >
> > > > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> > > >>
> > > >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> > > >> >
> > > >> > To enable semihosting we also need to enable the following
> > > >> > configs in defconfigs:
> > > >> > CONFIG_SEMIHOSTING
> > > >> > CONFIG_SPL_SEMIHOSTING
> > > >> > CONFIG_SEMIHOSTING_SERIAL
> > > >> > CONFIG_SERIAL_PROBE_ALL
> > > >> > CONFIG_SPL_FS_EXT4
> > > >> > CONFIG_SPL_FS_FAT
> > > >>
> > > >> Why should these _SPL_FS_xxx be required? If it's required by
> > > >> SEMIHOSTING, could the dependency be fixed there?
> > > >
> > > > The build dependencies require that these options be there.
> > >
> > > What error do you get?
> >
> > If I disable both the _SPL_FS_* config options then I get the
> > following compilation error:
> > common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
> > common/spl/spl_semihosting.c:27:32: error:
> > 'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
> > function)
> >    27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
> >       |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
> > is reported only once for each function it appears in
> >
> > Bin/Sean: This error is not really related to the semihosting feature
> > but is related to COFIG_SPL in general.
> > Can you please accept this patch-set and then I'll try and find time
> > in the future maybe to rectify this build dependency
> > problem ?
> >
> > >
> > > --Sean
> > >
> > > >>
> > > >> >
> > > >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > > >> > ---
> > > >> >  configs/qemu-riscv32_defconfig       | 4 ++++
> > > >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> > > >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> > > >> >  configs/qemu-riscv64_defconfig       | 4 ++++
> > > >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> > > >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> > > >> >  6 files changed, 30 insertions(+)
> > > >> >
> > > >>
> > > >> Regards,
> > > >> Bin
> > >

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Sean Anderson]

On 12/6/22 00:42, Kautuk Consul wrote:
> Hi,
> 
> On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
>>
>> On 12/5/22 00:51, Kautuk Consul wrote:
>> > Hi,
>> >
>> > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>> >>
>> >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
>> >> >
>> >> > To enable semihosting we also need to enable the following
>> >> > configs in defconfigs:
>> >> > CONFIG_SEMIHOSTING
>> >> > CONFIG_SPL_SEMIHOSTING
>> >> > CONFIG_SEMIHOSTING_SERIAL
>> >> > CONFIG_SERIAL_PROBE_ALL
>> >> > CONFIG_SPL_FS_EXT4
>> >> > CONFIG_SPL_FS_FAT
>> >>
>> >> Why should these _SPL_FS_xxx be required? If it's required by
>> >> SEMIHOSTING, could the dependency be fixed there?
>> >
>> > The build dependencies require that these options be there.
>>
>> What error do you get?
> 
> If I disable both the _SPL_FS_* config options then I get the
> following compilation error:
> common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
> common/spl/spl_semihosting.c:27:32: error:
> 'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
> function)
>    27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
>       |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
> is reported only once for each function it appears in
> 
> Bin/Sean: This error is not really related to the semihosting feature
> but is related to COFIG_SPL in general.
> Can you please accept this patch-set and then I'll try and find time
> in the future maybe to rectify this build dependency
> problem ?

config SPL_FS_LOAD_PAYLOAD_NAME
        string "File to load for U-Boot from the filesystem"
        depends on SPL_FS_EXT4 || SPL_FS_FAT || SPL_FS_SQUASHFS
        default "tispl.bin" if SYS_K3_SPL_ATF
        default "u-boot.itb" if SPL_LOAD_FIT
        default "u-boot.img"
        help
          Filename to read to load U-Boot when reading from filesystem.

Add CONFIG_SPL_SEMIHOSTING to the depends.

--Sean

>>
>> --Sean
>>
>> >>
>> >> >
>> >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
>> >> > ---
>> >> >  configs/qemu-riscv32_defconfig       | 4 ++++
>> >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
>> >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
>> >> >  configs/qemu-riscv64_defconfig       | 4 ++++
>> >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
>> >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
>> >> >  6 files changed, 30 insertions(+)
>> >> >
>> >>
>> >> Regards,
>> >> Bin
>>

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Leo Liang]

Hi Kautuk,

On Tue, Dec 06, 2022 at 05:02:49PM +0530, Kautuk Consul wrote:
> Hi Leo,
> 
> On Tue, Dec 6, 2022 at 4:29 PM Leo Liang <ycliang@andestech.com> wrote:
> >
> > Hi Kautuk,
> >
> > We have tested your patchset with QEMU 7.1.0.
> > It generally looks fine, but CI error seems to persist.
> > https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/14314
> >
> > The error comes from CI testcase timed-out.
> > The reason for the time-out is not yet confirmed,
> > but we suspect it's because when executing under semihosting,
> > QEMU could not exit normally. (thru ctrl+x a)
> >
> > There is a seemingly relevent patchset that sits on QEMU mailing list for some time.
> > https://lore.kernel.org/all/20220620190834.GA16887@ws2101.lin.mbt.kalray.eu/T/#m1bc32cc32511b6ac8adfaf67983dc2bccd4b9ec9
> >
> > On the u-boot side, what do you think if we disable semihosting by default?
> > (i.e., not adding CONFIG_SEMIHOSTING_XXX in qemu's defconfig)
> 
> I think it is okay to disable semihosting by default. Then the user
> will configure it when needed.
> So then can you ACK the first 2 patches ? I think we can leave out the
> 3rd qemu config patch for now.
>

No problem!
Additionally, could you rebase the patchset to current master, 
add what Sean suggested, and then send again?
I think I could merge your patch as soon as you re-send it.

Best regards,
Leo

> >
> > Best regards,
> > Leo
> >
> > On Tue, Dec 06, 2022 at 11:12:41AM +0530, Kautuk Consul wrote:
> > > Hi,
> > >
> > > On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
> > > >
> > > > On 12/5/22 00:51, Kautuk Consul wrote:
> > > > > Hi,
> > > > >
> > > > > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> > > > >>
> > > > >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> > > > >> >
> > > > >> > To enable semihosting we also need to enable the following
> > > > >> > configs in defconfigs:
> > > > >> > CONFIG_SEMIHOSTING
> > > > >> > CONFIG_SPL_SEMIHOSTING
> > > > >> > CONFIG_SEMIHOSTING_SERIAL
> > > > >> > CONFIG_SERIAL_PROBE_ALL
> > > > >> > CONFIG_SPL_FS_EXT4
> > > > >> > CONFIG_SPL_FS_FAT
> > > > >>
> > > > >> Why should these _SPL_FS_xxx be required? If it's required by
> > > > >> SEMIHOSTING, could the dependency be fixed there?
> > > > >
> > > > > The build dependencies require that these options be there.
> > > >
> > > > What error do you get?
> > >
> > > If I disable both the _SPL_FS_* config options then I get the
> > > following compilation error:
> > > common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
> > > common/spl/spl_semihosting.c:27:32: error:
> > > 'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
> > > function)
> > >    27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
> > >       |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
> > > is reported only once for each function it appears in
> > >
> > > Bin/Sean: This error is not really related to the semihosting feature
> > > but is related to COFIG_SPL in general.
> > > Can you please accept this patch-set and then I'll try and find time
> > > in the future maybe to rectify this build dependency
> > > problem ?
> > >
> > > >
> > > > --Sean
> > > >
> > > > >>
> > > > >> >
> > > > >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > > > >> > ---
> > > > >> >  configs/qemu-riscv32_defconfig       | 4 ++++
> > > > >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> > > > >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> > > > >> >  configs/qemu-riscv64_defconfig       | 4 ++++
> > > > >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> > > > >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> > > > >> >  6 files changed, 30 insertions(+)
> > > > >> >
> > > > >>
> > > > >> Regards,
> > > > >> Bin
> > > >

Re: [PATCH v5 3/3] board: qemu-riscv: enable semihosting

[Kautuk Consul]

Hi Leo,

Thanks! I have sent a v6 of this patchset wherein I have rebased the
patchset on the
latest master. I have removed the last patch with default config
options for qemu-riscv64
targets and have replaced it with a patch with Sean's suggestion for
adding to the
dependencies.

Thanks again.

On Wed, Dec 7, 2022 at 12:31 PM Leo Liang <ycliang@andestech.com> wrote:
>
> Hi Kautuk,
>
> On Tue, Dec 06, 2022 at 05:02:49PM +0530, Kautuk Consul wrote:
> > Hi Leo,
> >
> > On Tue, Dec 6, 2022 at 4:29 PM Leo Liang <ycliang@andestech.com> wrote:
> > >
> > > Hi Kautuk,
> > >
> > > We have tested your patchset with QEMU 7.1.0.
> > > It generally looks fine, but CI error seems to persist.
> > > https://source.denx.de/u-boot/custodians/u-boot-riscv/-/pipelines/14314
> > >
> > > The error comes from CI testcase timed-out.
> > > The reason for the time-out is not yet confirmed,
> > > but we suspect it's because when executing under semihosting,
> > > QEMU could not exit normally. (thru ctrl+x a)
> > >
> > > There is a seemingly relevent patchset that sits on QEMU mailing list for some time.
> > > https://lore.kernel.org/all/20220620190834.GA16887@ws2101.lin.mbt.kalray.eu/T/#m1bc32cc32511b6ac8adfaf67983dc2bccd4b9ec9
> > >
> > > On the u-boot side, what do you think if we disable semihosting by default?
> > > (i.e., not adding CONFIG_SEMIHOSTING_XXX in qemu's defconfig)
> >
> > I think it is okay to disable semihosting by default. Then the user
> > will configure it when needed.
> > So then can you ACK the first 2 patches ? I think we can leave out the
> > 3rd qemu config patch for now.
> >
>
> No problem!
> Additionally, could you rebase the patchset to current master,
> add what Sean suggested, and then send again?
> I think I could merge your patch as soon as you re-send it.
>
> Best regards,
> Leo
>
> > >
> > > Best regards,
> > > Leo
> > >
> > > On Tue, Dec 06, 2022 at 11:12:41AM +0530, Kautuk Consul wrote:
> > > > Hi,
> > > >
> > > > On Mon, Dec 5, 2022 at 8:46 PM Sean Anderson <sean.anderson@seco.com> wrote:
> > > > >
> > > > > On 12/5/22 00:51, Kautuk Consul wrote:
> > > > > > Hi,
> > > > > >
> > > > > > On Sat, Dec 3, 2022 at 9:44 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> > > > > >>
> > > > > >> On Fri, Sep 23, 2022 at 3:03 PM Kautuk Consul <kconsul@ventanamicro.com> wrote:
> > > > > >> >
> > > > > >> > To enable semihosting we also need to enable the following
> > > > > >> > configs in defconfigs:
> > > > > >> > CONFIG_SEMIHOSTING
> > > > > >> > CONFIG_SPL_SEMIHOSTING
> > > > > >> > CONFIG_SEMIHOSTING_SERIAL
> > > > > >> > CONFIG_SERIAL_PROBE_ALL
> > > > > >> > CONFIG_SPL_FS_EXT4
> > > > > >> > CONFIG_SPL_FS_FAT
> > > > > >>
> > > > > >> Why should these _SPL_FS_xxx be required? If it's required by
> > > > > >> SEMIHOSTING, could the dependency be fixed there?
> > > > > >
> > > > > > The build dependencies require that these options be there.
> > > > >
> > > > > What error do you get?
> > > >
> > > > If I disable both the _SPL_FS_* config options then I get the
> > > > following compilation error:
> > > > common/spl/spl_semihosting.c: In function 'spl_smh_load_image':
> > > > common/spl/spl_semihosting.c:27:32: error:
> > > > 'CONFIG_SPL_FS_LOAD_PAYLOAD_NAME' undeclared (first use in this
> > > > function)
> > > >    27 |         const char *filename = CONFIG_SPL_FS_LOAD_PAYLOAD_NAME;
> > > >       |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > > common/spl/spl_semihosting.c:27:32: note: each undeclared identifier
> > > > is reported only once for each function it appears in
> > > >
> > > > Bin/Sean: This error is not really related to the semihosting feature
> > > > but is related to COFIG_SPL in general.
> > > > Can you please accept this patch-set and then I'll try and find time
> > > > in the future maybe to rectify this build dependency
> > > > problem ?
> > > >
> > > > >
> > > > > --Sean
> > > > >
> > > > > >>
> > > > > >> >
> > > > > >> > Signed-off-by: Kautuk Consul <kconsul@ventanamicro.com>
> > > > > >> > ---
> > > > > >> >  configs/qemu-riscv32_defconfig       | 4 ++++
> > > > > >> >  configs/qemu-riscv32_smode_defconfig | 4 ++++
> > > > > >> >  configs/qemu-riscv32_spl_defconfig   | 7 +++++++
> > > > > >> >  configs/qemu-riscv64_defconfig       | 4 ++++
> > > > > >> >  configs/qemu-riscv64_smode_defconfig | 4 ++++
> > > > > >> >  configs/qemu-riscv64_spl_defconfig   | 7 +++++++
> > > > > >> >  6 files changed, 30 insertions(+)
> > > > > >> >
> > > > > >>
> > > > > >> Regards,
> > > > > >> Bin
> > > > >