hw/riscv: Add support for loading a firmware

Add support for loading a firmware file for the virt machine and the
SiFive U. This can be run with the following command:

    qemu-system-riscv64 -machine virt -bios fw_jump.bin -kernel vmlinux

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

hw/riscv/boot.c

@@ -23,8 +23,34 @@
 #include "exec/cpu-defs.h"
 #include "hw/loader.h"
 #include "hw/riscv/boot.h"
+#include "hw/boards.h"
 #include "elf.h"
 
+#if defined(TARGET_RISCV32)
+# define KERNEL_BOOT_ADDRESS 0x80400000
+#else
+# define KERNEL_BOOT_ADDRESS 0x80200000
+#endif
+
+target_ulong riscv_load_firmware(const char *firmware_filename,
+                                 hwaddr firmware_load_addr)
+{
+    uint64_t firmware_entry, firmware_start, firmware_end;
+
+    if (load_elf(firmware_filename, NULL, NULL, NULL, &firmware_entry,
+                 &firmware_start, &firmware_end, 0, EM_RISCV, 1, 0) > 0) {
+        return firmware_entry;
+    }
+
+    if (load_image_targphys_as(firmware_filename, firmware_load_addr,
+                               ram_size, NULL) > 0) {
+        return firmware_load_addr;
+    }
+
+    error_report("could not load firmware '%s'", firmware_filename);
+    exit(1);
+}
+
 target_ulong riscv_load_kernel(const char *kernel_filename)
 {
     uint64_t kernel_entry, kernel_high;

hw/riscv/sifive_u.c

@@ -269,6 +269,10 @@ static void riscv_sifive_u_init(MachineState *machine)
     /* create device tree */
     create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
 
+    if (machine->firmware) {
+        riscv_load_firmware(machine->firmware, memmap[SIFIVE_U_DRAM].base);
+    }
+
     if (machine->kernel_filename) {
         riscv_load_kernel(machine->kernel_filename);
     }

hw/riscv/virt.c

@@ -398,6 +398,10 @@ static void riscv_virt_board_init(MachineState *machine)
     memory_region_add_subregion(system_memory, memmap[VIRT_MROM].base,
                                 mask_rom);
 
+    if (machine->firmware) {
+        riscv_load_firmware(machine->firmware, memmap[VIRT_DRAM].base);
+    }
+
     if (machine->kernel_filename) {
         uint64_t kernel_entry = riscv_load_kernel(machine->kernel_filename);
 

include/hw/riscv/boot.h

@@ -20,6 +20,8 @@
 #ifndef RISCV_BOOT_H
 #define RISCV_BOOT_H
 
+target_ulong riscv_load_firmware(const char *firmware_filename,
+                                 hwaddr firmware_load_addr);
 target_ulong riscv_load_kernel(const char *kernel_filename);
 hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
                          uint64_t kernel_entry, hwaddr *start);