[PATCH v2 0/4] QEMU spike machine support for U-Boot

[PATCH v2 0/4] QEMU spike machine support for U-Boot

[Anup Patel]

We can use same U-Boot binary compiled using qemu-riscv64_smode_defconfig
on QEMU virt machine and QEMU spike machine. To achieve this, we need HTIF
console support for U-Boot QEMU RISC-V board hence this series.

To test this series with latest OpenSBI, we can use the following command:
qemu-system-riscv64 -M spike -m 256M -display none -serial stdio \
-bios opensbi/build/platform/generic/firmware/fw_jump.bin -kernel \
./u-boot/u-boot.bin

These patch can be found in qemu_riscv_htif_v2 branch at:
https://github.com/avpatel/u-boot.git

Changes since v1:
 - Use ofnode_by_compatible() in PATCH3
 - Updated QEMU RISC-V documentation in PATCH4

Anup Patel (4):
  serial: Add RISC-V HTIF console driver
  riscv: qemu: Enable HTIF console support
  riscv: qemu: Implement is_flash_available() for MTD NOR
  doc: qemu-riscv: Update documentation for QEMU spike machine

 board/emulation/qemu-riscv/Kconfig      |   1 +
 board/emulation/qemu-riscv/qemu-riscv.c |  12 ++
 doc/board/emulation/qemu-riscv.rst      |  48 ++++---
 drivers/serial/Kconfig                  |   8 ++
 drivers/serial/Makefile                 |   1 +
 drivers/serial/serial_htif.c            | 178 ++++++++++++++++++++++++
 6 files changed, 232 insertions(+), 16 deletions(-)
 create mode 100644 drivers/serial/serial_htif.c

-- 
2.25.1

[PATCH v2 1/4] serial: Add RISC-V HTIF console driver

[Anup Patel]

Quite a few RISC-V emulators and ISS (including Spike) have host
transfer interface (HTIF) based console. This patch adds HTIF
based console driver for RISC-V platforms which depends totally
on DT node for HTIF register base address.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Rick Chen <rick@andestech.com>
---
 drivers/serial/Kconfig       |   8 ++
 drivers/serial/Makefile      |   1 +
 drivers/serial/serial_htif.c | 178 +++++++++++++++++++++++++++++++++++
 3 files changed, 187 insertions(+)
 create mode 100644 drivers/serial/serial_htif.c

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 6c8fdda9a0..345d1881f5 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -866,6 +866,14 @@ config PXA_SERIAL
 	  If you have a machine based on a Marvell XScale PXA2xx CPU you
 	  can enable its onboard serial ports by enabling this option.
 
+config HTIF_CONSOLE
+	bool "RISC-V HTIF console support"
+	depends on DM_SERIAL && 64BIT
+	help
+	  Select this to enable host transfer interface (HTIF) based serial
+	  console. The HTIF device is quite common in RISC-V emulators and
+	  RISC-V ISS so this driver allows using U-Boot on such platforms.
+
 config SIFIVE_SERIAL
 	bool "SiFive UART support"
 	depends on DM_SERIAL
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 8168af640f..52e70aa191 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -73,6 +73,7 @@ obj-$(CONFIG_OWL_SERIAL) += serial_owl.o
 obj-$(CONFIG_OMAP_SERIAL) += serial_omap.o
 obj-$(CONFIG_MTK_SERIAL) += serial_mtk.o
 obj-$(CONFIG_MT7620_SERIAL) += serial_mt7620.o
+obj-$(CONFIG_HTIF_CONSOLE) += serial_htif.o
 obj-$(CONFIG_SIFIVE_SERIAL) += serial_sifive.o
 obj-$(CONFIG_XEN_SERIAL) += serial_xen.o
 
diff --git a/drivers/serial/serial_htif.c b/drivers/serial/serial_htif.c
new file mode 100644
index 0000000000..5d2bf0aaeb
--- /dev/null
+++ b/drivers/serial/serial_htif.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <log.h>
+#include <watchdog.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <linux/compiler.h>
+#include <serial.h>
+#include <linux/err.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define HTIF_DATA_BITS		48
+#define HTIF_DATA_MASK		((1ULL << HTIF_DATA_BITS) - 1)
+#define HTIF_DATA_SHIFT		0
+#define HTIF_CMD_BITS		8
+#define HTIF_CMD_MASK		((1ULL << HTIF_CMD_BITS) - 1)
+#define HTIF_CMD_SHIFT		48
+#define HTIF_DEV_BITS		8
+#define HTIF_DEV_MASK		((1ULL << HTIF_DEV_BITS) - 1)
+#define HTIF_DEV_SHIFT		56
+
+#define HTIF_DEV_SYSTEM		0
+#define HTIF_DEV_CONSOLE	1
+
+#define HTIF_CONSOLE_CMD_GETC	0
+#define HTIF_CONSOLE_CMD_PUTC	1
+
+#if __riscv_xlen == 64
+# define TOHOST_CMD(dev, cmd, payload) \
+	(((u64)(dev) << HTIF_DEV_SHIFT) | \
+	 ((u64)(cmd) << HTIF_CMD_SHIFT) | \
+	 (u64)(payload))
+#else
+# define TOHOST_CMD(dev, cmd, payload) ({ \
+	if ((dev) || (cmd)) \
+		__builtin_trap(); \
+	(payload); })
+#endif
+#define FROMHOST_DEV(fromhost_value) \
+	((u64)((fromhost_value) >> HTIF_DEV_SHIFT) & HTIF_DEV_MASK)
+#define FROMHOST_CMD(fromhost_value) \
+	((u64)((fromhost_value) >> HTIF_CMD_SHIFT) & HTIF_CMD_MASK)
+#define FROMHOST_DATA(fromhost_value) \
+	((u64)((fromhost_value) >> HTIF_DATA_SHIFT) & HTIF_DATA_MASK)
+
+struct htif_plat {
+	void *fromhost;
+	void *tohost;
+	int console_char;
+};
+
+static void __check_fromhost(struct htif_plat *plat)
+{
+	u64 fh = readq(plat->fromhost);
+
+	if (!fh)
+		return;
+	writeq(0, plat->fromhost);
+
+	/* this should be from the console */
+	if (FROMHOST_DEV(fh) != HTIF_DEV_CONSOLE)
+		__builtin_trap();
+	switch (FROMHOST_CMD(fh)) {
+	case HTIF_CONSOLE_CMD_GETC:
+		plat->console_char = 1 + (u8)FROMHOST_DATA(fh);
+		break;
+	case HTIF_CONSOLE_CMD_PUTC:
+		break;
+	default:
+		__builtin_trap();
+	}
+}
+
+static void __set_tohost(struct htif_plat *plat,
+			 u64 dev, u64 cmd, u64 data)
+{
+	while (readq(plat->tohost))
+		__check_fromhost(plat);
+	writeq(TOHOST_CMD(dev, cmd, data), plat->tohost);
+}
+
+static int htif_serial_putc(struct udevice *dev, const char ch)
+{
+	struct htif_plat *plat = dev_get_plat(dev);
+
+	__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_PUTC, ch);
+	return 0;
+}
+
+static int htif_serial_getc(struct udevice *dev)
+{
+	int ch;
+	struct htif_plat *plat = dev_get_plat(dev);
+
+	if (plat->console_char < 0)
+		__check_fromhost(plat);
+
+	if (plat->console_char >= 0) {
+		ch = plat->console_char;
+		plat->console_char = -1;
+		__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_GETC, 0);
+		return (ch) ? ch - 1 : -EAGAIN;
+	}
+
+	return -EAGAIN;
+}
+
+static int htif_serial_pending(struct udevice *dev, bool input)
+{
+	struct htif_plat *plat = dev_get_plat(dev);
+
+	if (!input)
+		return 0;
+
+	if (plat->console_char < 0)
+		__check_fromhost(plat);
+
+	return (plat->console_char >= 0) ? 1 : 0;
+}
+
+static int htif_serial_probe(struct udevice *dev)
+{
+	struct htif_plat *plat = dev_get_plat(dev);
+
+	/* Queue first getc request */
+	__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_GETC, 0);
+
+	return 0;
+}
+
+static int htif_serial_of_to_plat(struct udevice *dev)
+{
+	fdt_addr_t addr;
+	struct htif_plat *plat = dev_get_plat(dev);
+
+	addr = dev_read_addr_index(dev, 0);
+	if (addr == FDT_ADDR_T_NONE)
+		return -ENODEV;
+	plat->fromhost = (void *)(uintptr_t)addr;
+	plat->tohost = plat->fromhost + sizeof(u64);
+
+	addr = dev_read_addr_index(dev, 1);
+	if (addr != FDT_ADDR_T_NONE)
+		plat->tohost = (void *)(uintptr_t)addr;
+
+	plat->console_char = -1;
+
+	return 0;
+}
+
+static const struct dm_serial_ops htif_serial_ops = {
+	.putc = htif_serial_putc,
+	.getc = htif_serial_getc,
+	.pending = htif_serial_pending,
+};
+
+static const struct udevice_id htif_serial_ids[] = {
+	{ .compatible = "ucb,htif0" },
+	{ }
+};
+
+U_BOOT_DRIVER(serial_htif) = {
+	.name		= "serial_htif",
+	.id		= UCLASS_SERIAL,
+	.of_match	= htif_serial_ids,
+	.of_to_plat	= htif_serial_of_to_plat,
+	.plat_auto	= sizeof(struct htif_plat),
+	.probe		= htif_serial_probe,
+	.ops		= &htif_serial_ops,
+};
-- 
2.25.1

[PATCH v2 2/4] riscv: qemu: Enable HTIF console support

[Anup Patel]

Enable support for HTIF console so that we can use QEMU RISC-V U-Boot
on RISC-V emulators and ISS having it.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Rick Chen <rick@andestech.com>
---
 board/emulation/qemu-riscv/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/board/emulation/qemu-riscv/Kconfig b/board/emulation/qemu-riscv/Kconfig
index 1bbf1bc84a..f7538bc496 100644
--- a/board/emulation/qemu-riscv/Kconfig
+++ b/board/emulation/qemu-riscv/Kconfig
@@ -56,6 +56,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	imply DM_SCSI
 	imply SYS_NS16550
 	imply SIFIVE_SERIAL
+	imply HTIF_CONSOLE if 64BIT
 	imply SYSRESET
 	imply SYSRESET_CMD_POWEROFF
 	imply SYSRESET_SYSCON
-- 
2.25.1

[PATCH v2 3/4] riscv: qemu: Implement is_flash_available() for MTD NOR

[Anup Patel]

Currently, if MTD NOR is enabled then U-Boot tries to issue flash
commands even when CFI flash DT node is not present. This causes
access fault on RISC-V emulators or ISS which do not emulate CFI
flash. To handle this issue, we implement is_flash_available() for
qemu-riscv board which will return 1 only if CFI flash DT node is
present.

Fixes: d248627f9d42 ("riscv: qemu: Enable MTD NOR flash support")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Rick Chen <rick@andestech.com>
---
 board/emulation/qemu-riscv/qemu-riscv.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
index b0d9dd59b1..ae3b7a3295 100644
--- a/board/emulation/qemu-riscv/qemu-riscv.c
+++ b/board/emulation/qemu-riscv/qemu-riscv.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/ofnode.h>
 #include <env.h>
 #include <fdtdec.h>
 #include <image.h>
@@ -16,6 +17,17 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#if IS_ENABLED(CONFIG_MTD_NOR_FLASH)
+int is_flash_available(void)
+{
+	if (!ofnode_equal(ofnode_by_compatible(ofnode_null(), "cfi-flash"),
+			  ofnode_null()))
+		return 1;
+
+	return 0;
+}
+#endif
+
 int board_init(void)
 {
 	/*
-- 
2.25.1

[PATCH v2 4/4] doc: qemu-riscv: Update documentation for QEMU spike machine

[Anup Patel]

We can now use same U-Boot images on both QEMU virt machine and QEMU
spike machine so let's update the QEMU RISC-V documentation.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 doc/board/emulation/qemu-riscv.rst | 48 ++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/doc/board/emulation/qemu-riscv.rst b/doc/board/emulation/qemu-riscv.rst
index 4b8e104a21..0a4b121687 100644
--- a/doc/board/emulation/qemu-riscv.rst
+++ b/doc/board/emulation/qemu-riscv.rst
@@ -4,16 +4,21 @@
 QEMU RISC-V
 ===========
 
-QEMU for RISC-V supports a special 'virt' machine designed for emulation and
-virtualization purposes. This document describes how to run U-Boot under it.
-Both 32-bit and 64-bit targets are supported, running in either machine or
-supervisor mode.
+QEMU for RISC-V supports a special 'virt' machine and 'spike' machine designed
+for emulation and virtualization purposes. This document describes how to run
+U-Boot under it. Both 32-bit and 64-bit targets are supported, running in
+either machine or supervisor mode.
 
 The QEMU virt machine models a generic RISC-V virtual machine with support for
 the VirtIO standard networking and block storage devices. It has CLINT, PLIC,
 16550A UART devices in addition to VirtIO and it also uses device-tree to pass
-configuration information to guest software. It implements RISC-V privileged
-architecture spec v1.10.
+configuration information to guest software. It implements the latest RISC-V
+privileged architecture.
+
+The QEMU spike machine models a minimalistic RISC-V virtual machine with
+only CLINT and HTIF devices. It also uses device-tree to pass configuration
+information to guest software and implements the latest RISC-V privileged
+architecture.
 
 Building U-Boot
 ---------------
@@ -38,13 +43,17 @@ Running U-Boot
 --------------
 The minimal QEMU command line to get U-Boot up and running is:
 
-- For 32-bit RISC-V::
+- For 32-bit RISC-V virt machine::
 
-    qemu-system-riscv32 -nographic -machine virt -bios u-boot
+    qemu-system-riscv32 -nographic -machine virt -bios u-boot.bin
 
-- For 64-bit RISC-V::
+- For 64-bit RISC-V virt machine::
+
+    qemu-system-riscv64 -nographic -machine virt -bios u-boot.bin
+
+- For 64-bit RISC-V spike machine::
 
-    qemu-system-riscv64 -nographic -machine virt -bios u-boot
+    qemu-system-riscv64 -nographic -machine spike -bios u-boot.bin
 
 The commands above create targets with 128MiB memory by default.
 A freely configurable amount of RAM can be created via the '-m'
@@ -55,6 +64,7 @@ the new setting.
 For instructions on how to run U-Boot in supervisor mode on QEMU
 with OpenSBI, see the documentation available with OpenSBI:
 https://github.com/riscv/opensbi/blob/master/docs/platform/qemu_virt.md
+https://github.com/riscv/opensbi/blob/master/docs/platform/spike.md
 
 These have been tested in QEMU 5.0.0.
 
@@ -77,8 +87,9 @@ supported by U-Boot. Clone the OpenSBI repository and run the following command.
 
 See the OpenSBI documentation for full details:
 https://github.com/riscv/opensbi/blob/master/docs/platform/qemu_virt.md
+https://github.com/riscv/opensbi/blob/master/docs/platform/spike.md
 
-To make the FW_DYNAMIC binary (build/platform/qemu/virt/firmware/fw_dynamic.bin)
+To make the FW_DYNAMIC binary (build/platform/generic/firmware/fw_dynamic.bin)
 available to U-Boot, either copy it into the U-Boot root directory or specify
 its location with the OPENSBI environment variable. Afterwards, compile U-Boot
 with the following commands.
@@ -96,17 +107,22 @@ with the following commands.
 The minimal QEMU commands to run U-Boot SPL in both 32-bit and 64-bit
 configurations are:
 
-- For 32-bit RISC-V::
+- For 32-bit RISC-V virt machine::
 
-    qemu-system-riscv32 -nographic -machine virt -bios spl/u-boot-spl \
+    qemu-system-riscv32 -nographic -machine virt -bios spl/u-boot-spl.bin \
     -device loader,file=u-boot.itb,addr=0x80200000
 
-- For 64-bit RISC-V::
+- For 64-bit RISC-V virt machine::
+
+    qemu-system-riscv64 -nographic -machine virt -bios spl/u-boot-spl.bin \
+    -device loader,file=u-boot.itb,addr=0x80200000
+
+- For 64-bit RISC-V spike machine::
 
-    qemu-system-riscv64 -nographic -machine virt -bios spl/u-boot-spl \
+    qemu-system-riscv64 -nographic -machine spike -bios spl/u-boot-spl.bin \
     -device loader,file=u-boot.itb,addr=0x80200000
 
-An attached disk can be emulated by adding::
+An attached disk can be emulated in RISC-V virt machine by adding::
 
     -device ich9-ahci,id=ahci \
     -drive if=none,file=riscv64.img,format=raw,id=mydisk \
-- 
2.25.1

Re: [PATCH v2 4/4] doc: qemu-riscv: Update documentation for QEMU spike machine

[Bin Meng]

On Thu, Jan 27, 2022 at 2:11 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> We can now use same U-Boot images on both QEMU virt machine and QEMU
> spike machine so let's update the QEMU RISC-V documentation.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  doc/board/emulation/qemu-riscv.rst | 48 ++++++++++++++++++++----------
>  1 file changed, 32 insertions(+), 16 deletions(-)
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Re: [PATCH v2 3/4] riscv: qemu: Implement is_flash_available() for MTD NOR

[Bin Meng]

On Thu, Jan 27, 2022 at 2:11 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> Currently, if MTD NOR is enabled then U-Boot tries to issue flash
> commands even when CFI flash DT node is not present. This causes
> access fault on RISC-V emulators or ISS which do not emulate CFI
> flash. To handle this issue, we implement is_flash_available() for
> qemu-riscv board which will return 1 only if CFI flash DT node is
> present.
>
> Fixes: d248627f9d42 ("riscv: qemu: Enable MTD NOR flash support")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Reviewed-by: Rick Chen <rick@andestech.com>
> ---
>  board/emulation/qemu-riscv/qemu-riscv.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

Re: [PATCH v2 2/4] riscv: qemu: Enable HTIF console support

[Bin Meng]

On Thu, Jan 27, 2022 at 2:11 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> Enable support for HTIF console so that we can use QEMU RISC-V U-Boot
> on RISC-V emulators and ISS having it.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
> Reviewed-by: Rick Chen <rick@andestech.com>
> ---
>  board/emulation/qemu-riscv/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

Re: [PATCH v2 1/4] serial: Add RISC-V HTIF console driver

[Bin Meng]

On Thu, Jan 27, 2022 at 2:11 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> Quite a few RISC-V emulators and ISS (including Spike) have host
> transfer interface (HTIF) based console. This patch adds HTIF
> based console driver for RISC-V platforms which depends totally
> on DT node for HTIF register base address.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
> Reviewed-by: Rick Chen <rick@andestech.com>
> ---
>  drivers/serial/Kconfig       |   8 ++
>  drivers/serial/Makefile      |   1 +
>  drivers/serial/serial_htif.c | 178 +++++++++++++++++++++++++++++++++++
>  3 files changed, 187 insertions(+)
>  create mode 100644 drivers/serial/serial_htif.c
>

Tested-by: Bin Meng <bmeng.cn@gmail.com>

Re: [PATCH v2 0/4] QEMU spike machine support for U-Boot

[Anup Patel]

Hi Rick,

On Thu, Jan 27, 2022 at 11:41 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> We can use same U-Boot binary compiled using qemu-riscv64_smode_defconfig
> on QEMU virt machine and QEMU spike machine. To achieve this, we need HTIF
> console support for U-Boot QEMU RISC-V board hence this series.
>
> To test this series with latest OpenSBI, we can use the following command:
> qemu-system-riscv64 -M spike -m 256M -display none -serial stdio \
> -bios opensbi/build/platform/generic/firmware/fw_jump.bin -kernel \
> ./u-boot/u-boot.bin
>
> These patch can be found in qemu_riscv_htif_v2 branch at:
> https://github.com/avpatel/u-boot.git
>
> Changes since v1:
>  - Use ofnode_by_compatible() in PATCH3
>  - Updated QEMU RISC-V documentation in PATCH4
>
> Anup Patel (4):
>   serial: Add RISC-V HTIF console driver
>   riscv: qemu: Enable HTIF console support
>   riscv: qemu: Implement is_flash_available() for MTD NOR
>   doc: qemu-riscv: Update documentation for QEMU spike machine

Can this series be considered for the upcoming v2022.04 release ?

Best Regards,
Anup

>
>  board/emulation/qemu-riscv/Kconfig      |   1 +
>  board/emulation/qemu-riscv/qemu-riscv.c |  12 ++
>  doc/board/emulation/qemu-riscv.rst      |  48 ++++---
>  drivers/serial/Kconfig                  |   8 ++
>  drivers/serial/Makefile                 |   1 +
>  drivers/serial/serial_htif.c            | 178 ++++++++++++++++++++++++
>  6 files changed, 232 insertions(+), 16 deletions(-)
>  create mode 100644 drivers/serial/serial_htif.c
>
> --
> 2.25.1
>

Re: [PATCH v2 3/4] riscv: qemu: Implement is_flash_available() for MTD NOR

[Heinrich Schuchardt]

On 1/27/22 07:11, Anup Patel wrote:
> Currently, if MTD NOR is enabled then U-Boot tries to issue flash
> commands even when CFI flash DT node is not present. This causes
> access fault on RISC-V emulators or ISS which do not emulate CFI
> flash. To handle this issue, we implement is_flash_available() for
> qemu-riscv board which will return 1 only if CFI flash DT node is
> present.
> 
> Fixes: d248627f9d42 ("riscv: qemu: Enable MTD NOR flash support")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> Reviewed-by: Rick Chen <rick@andestech.com>
> ---
>   board/emulation/qemu-riscv/qemu-riscv.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
> 
> diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
> index b0d9dd59b1..ae3b7a3295 100644
> --- a/board/emulation/qemu-riscv/qemu-riscv.c
> +++ b/board/emulation/qemu-riscv/qemu-riscv.c
> @@ -5,6 +5,7 @@
>   
>   #include <common.h>
>   #include <dm.h>
> +#include <dm/ofnode.h>
>   #include <env.h>
>   #include <fdtdec.h>
>   #include <image.h>
> @@ -16,6 +17,17 @@
>   
>   DECLARE_GLOBAL_DATA_PTR;
>   
> +#if IS_ENABLED(CONFIG_MTD_NOR_FLASH)

I do not think that we need an #if here. The weak function is only 
defined and called if CONFIG_MTD_NOR_FLASH=y (cf. common/board_r.c). 
Without the #if the linker will detect that this function is not needed 
and will eliminate it if CONFIG_MTD_NOR_FLASH=n.

As this ensures that the function is always compiled this is the 
preferred way of implementation.

> +int is_flash_available(void)

Currently there is no include defining the is_flash_available(). This 
needs to be fixed.

Best regards

Heinrich

> +{
> +	if (!ofnode_equal(ofnode_by_compatible(ofnode_null(), "cfi-flash"),
> +			  ofnode_null()))
> +		return 1;
> +
> +	return 0;
> +}
> +#endif
> +
>   int board_init(void)
>   {
>   	/*

Re: [PATCH v2 0/4] QEMU spike machine support for U-Boot

[Rick Chen]

HI Anup,

> From: Anup Patel <anup@brainfault.org>
> Sent: Sunday, February 06, 2022 4:41 PM
> To: Rick Jian-Zhi Chen(陳建志) <rick@andestech.com>
> Cc: Bin Meng <bmeng.cn@gmail.com>; Atish Patra <atishp@atishpatra.org>; Alistair Francis <Alistair.Francis@wdc.com>; Anup Patel <apatel@ventanamicro.com>; U-Boot Mailing List <u-boot@lists.denx.de>
> Subject: Re: [PATCH v2 0/4] QEMU spike machine support for U-Boot
>
> Hi Rick,
>
> On Thu, Jan 27, 2022 at 11:41 AM Anup Patel <apatel@ventanamicro.com> wrote:
> >
> > We can use same U-Boot binary compiled using
> > qemu-riscv64_smode_defconfig on QEMU virt machine and QEMU spike
> > machine. To achieve this, we need HTIF console support for U-Boot QEMU RISC-V board hence this series.
> >
> > To test this series with latest OpenSBI, we can use the following command:
> > qemu-system-riscv64 -M spike -m 256M -display none -serial stdio \
> > -bios opensbi/build/platform/generic/firmware/fw_jump.bin -kernel \
> > ./u-boot/u-boot.bin
> >
> > These patch can be found in qemu_riscv_htif_v2 branch at:
> > https://github.com/avpatel/u-boot.git
> >
> > Changes since v1:
> >  - Use ofnode_by_compatible() in PATCH3
> >  - Updated QEMU RISC-V documentation in PATCH4
> >
> > Anup Patel (4):
> >   serial: Add RISC-V HTIF console driver
> >   riscv: qemu: Enable HTIF console support
> >   riscv: qemu: Implement is_flash_available() for MTD NOR
> >   doc: qemu-riscv: Update documentation for QEMU spike machine
>
> Can this series be considered for the upcoming v2022.04 release ?

Yes,  cc Leo and he will follow this series and apply ASAP.

Thanks,
Rick