Re: [PATCH v2 1/5] mac_oldworld: Allow loading binary ROM image

[Mark Cave-Ayland]

On 13/06/2020 14:36, BALATON Zoltan wrote:

> The G3 beige machine has a 4MB firmware ROM. Fix the size of the rom
> region and allow loading a binary image with -bios. This makes it
> possible to test emulation with a ROM image from real hardware.
> 
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  hw/ppc/mac_oldworld.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/ppc/mac_oldworld.c b/hw/ppc/mac_oldworld.c
> index 0b4c1c6373..3812adc441 100644
> --- a/hw/ppc/mac_oldworld.c
> +++ b/hw/ppc/mac_oldworld.c
> @@ -59,6 +59,8 @@
>  #define NDRV_VGA_FILENAME "qemu_vga.ndrv"
>  
>  #define GRACKLE_BASE 0xfec00000
> +#define PROM_BASE 0xffc00000
> +#define PROM_SIZE (4 * MiB)
>  
>  static void fw_cfg_boot_set(void *opaque, const char *boot_device,
>                              Error **errp)
> @@ -127,24 +129,28 @@ static void ppc_heathrow_init(MachineState *machine)
>  
>      memory_region_add_subregion(sysmem, 0, machine->ram);
>  
> -    /* allocate and load BIOS */
> -    memory_region_init_rom(bios, NULL, "ppc_heathrow.bios", BIOS_SIZE,
> +    /* allocate and load firmware ROM */
> +    memory_region_init_rom(bios, NULL, "ppc_heathrow.bios", PROM_SIZE,
>                             &error_fatal);
> +    memory_region_add_subregion(sysmem, PROM_BASE, bios);
>  
> -    if (bios_name == NULL)
> +    if (!bios_name) {
>          bios_name = PROM_FILENAME;
> +    }
>      filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
> -    memory_region_add_subregion(sysmem, PROM_ADDR, bios);
> -
> -    /* Load OpenBIOS (ELF) */
>      if (filename) {
> -        bios_size = load_elf(filename, NULL, 0, NULL, NULL, NULL, NULL, NULL,
> -                             1, PPC_ELF_MACHINE, 0, 0);
> +        /* Load OpenBIOS (ELF) */
> +        bios_size = load_elf(filename, NULL, NULL, NULL, NULL, NULL, NULL,
> +                             NULL, 1, PPC_ELF_MACHINE, 0, 0);
> +        if (bios_size <= 0) {
> +            /* or load binary ROM image */
> +            bios_size = load_image_targphys(filename, PROM_BASE, PROM_SIZE);
> +        }
>          g_free(filename);
>      } else {
>          bios_size = -1;
>      }
> -    if (bios_size < 0 || bios_size > BIOS_SIZE) {
> +    if (bios_size < 0 || bios_size > PROM_SIZE) {
>          error_report("could not load PowerPC bios '%s'", bios_name);
>          exit(1);
>      }

I think the logic could be improved a bit here: load_elf() can return the 
physical
address from the ELF, so it would make sense to use that as the address for
load_image_targphys() if present, and otherwise fall back to loading at 
0xffc00000.

It may also make sense to split PROM_ADDR to PROM_ADDR_OLDWORLD and
PROM_ADDR_NEWWORLD (and similar for BIOS_SIZE) to allow these values to be 
adjusted
separately for each machine.


ATB,

Mark.