[PATCH v3 10/17] hw/arm/allwinner-h3: add Boot ROM support

[Niek Linnenbank <nieklinnenbank@gmail.com>]

A real Allwinner H3 SoC contains a Boot ROM which is the
first code that runs right after the SoC is powered on.
The Boot ROM is responsible for loading user code (e.g. a bootloader)
from any of the supported external devices and writing the downloaded
code to internal SRAM. After loading the SoC begins executing the code
written to SRAM. This commits adds emulation of the Boot ROM firmware
setup functionality by loading user code from SD card.

Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
---
 include/hw/arm/allwinner-h3.h | 23 +++++++++++++++++++++++
 hw/arm/allwinner-h3.c         | 28 ++++++++++++++++++++++++++++
 hw/arm/orangepi.c             |  3 +++
 3 files changed, 54 insertions(+)

diff --git a/include/hw/arm/allwinner-h3.h b/include/hw/arm/allwinner-h3.h
index 5d74cca28e..4b66227ac4 100644
--- a/include/hw/arm/allwinner-h3.h
+++ b/include/hw/arm/allwinner-h3.h
@@ -50,6 +50,7 @@
 #include "hw/sd/allwinner-sdhost.h"
 #include "hw/net/allwinner-sun8i-emac.h"
 #include "target/arm/cpu.h"
+#include "sysemu/block-backend.h"
 
 /**
  * Allwinner H3 device list
@@ -130,4 +131,26 @@ typedef struct AwH3State {
     MemoryRegion sram_c;
 } AwH3State;
 
+/**
+ * Emulate Boot ROM firmware setup functionality.
+ *
+ * A real Allwinner H3 SoC contains a Boot ROM
+ * which is the first code that runs right after
+ * the SoC is powered on. The Boot ROM is responsible
+ * for loading user code (e.g. a bootloader) from any
+ * of the supported external devices and writing the
+ * downloaded code to internal SRAM. After loading the SoC
+ * begins executing the code written to SRAM.
+ *
+ * This function emulates the Boot ROM by copying 32 KiB
+ * of data from the given block device and writes it to
+ * the start of the first internal SRAM memory.
+ *
+ * @s: Allwinner H3 state object pointer
+ * @blk: Block backend device object pointer
+ * @errp: Error object pointer for raising errors
+ */
+void allwinner_h3_bootrom_setup(AwH3State *s, BlockBackend *blk,
+                                Error **errp);
+
 #endif /* HW_ARM_ALLWINNER_H3_H */
diff --git a/hw/arm/allwinner-h3.c b/hw/arm/allwinner-h3.c
index e692432b4e..e7b768ad5b 100644
--- a/hw/arm/allwinner-h3.c
+++ b/hw/arm/allwinner-h3.c
@@ -27,6 +27,7 @@
 #include "hw/char/serial.h"
 #include "hw/misc/unimp.h"
 #include "hw/usb/hcd-ehci.h"
+#include "hw/loader.h"
 #include "sysemu/sysemu.h"
 #include "hw/arm/allwinner-h3.h"
 
@@ -168,6 +169,33 @@ enum {
     AW_H3_GIC_NUM_SPI       = 128
 };
 
+void allwinner_h3_bootrom_setup(AwH3State *s, BlockBackend *blk, Error **errp)
+{
+    uint8_t *buffer;
+    int64_t rom_size = 32 * KiB;
+
+    int64_t blk_size = blk_getlength(blk);
+    if (blk_size <= 0) {
+        error_setg(errp, "%s: failed to get BlockBackend size", __func__);
+        return;
+    }
+
+    if (rom_size > blk_size) {
+        rom_size = blk_size;
+    }
+
+    buffer = g_new0(uint8_t, rom_size);
+    if (blk_pread(blk, 8 * KiB, buffer, rom_size) < 0) {
+        error_setg(errp, "%s: failed to read BlockBackend data", __func__);
+        return;
+    }
+
+    rom_add_blob("allwinner-h3.bootrom", buffer, rom_size,
+                  rom_size, s->memmap[AW_H3_SRAM_A1],
+                  NULL, NULL, NULL, NULL, false);
+    g_free(buffer);
+}
+
 static void allwinner_h3_init(Object *obj)
 {
     AwH3State *s = AW_H3(obj);
diff --git a/hw/arm/orangepi.c b/hw/arm/orangepi.c
index 0eb52eb813..b722f49485 100644
--- a/hw/arm/orangepi.c
+++ b/hw/arm/orangepi.c
@@ -93,6 +93,9 @@ static void orangepi_init(MachineState *machine)
     if (bios_name) {
         error_report("BIOS not supported for this machine");
         exit(1);
+    } else if (!machine->kernel_filename && blk_is_available(blk)) {
+        /* Use Boot ROM to copy data from SD card to SRAM */
+        allwinner_h3_bootrom_setup(s->h3, blk, &error_fatal);
     }
     orangepi_binfo.loader_start = s->h3->memmap[AW_H3_SDRAM];
     orangepi_binfo.ram_size = machine->ram_size;
-- 
2.17.1