Re: [PULL 2/2] ppc/amigaone: Allow running AmigaOS without firmware image

[BALATON Zoltan]

On Thu, 30 Nov 2023, Nicholas Piggin wrote:
> From: BALATON Zoltan <balaton@eik.bme.hu>
>
> The machine uses a modified U-Boot under GPL license but the sources
> of it are lost with only a binary available so it cannot be included
> in QEMU. Allow running without the firmware image which can be used
> when calling a boot loader directly and thus simplifying booting
> guests. We need a small routine that AmigaOS calls from ROM which is
> added in this case to allow booting AmigaOS without external firmware
> image.

Wrong version. I've sent a v4 of this patch yesterday.

Regards,
BALATON Zoltan

> Fixes: d9656f860a38 ("hw/ppc: Add emulation of AmigaOne XE board")
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> hw/ppc/amigaone.c | 35 +++++++++++++++++++++++------------
> 1 file changed, 23 insertions(+), 12 deletions(-)
>
> diff --git a/hw/ppc/amigaone.c b/hw/ppc/amigaone.c
> index 992a55e632..ddfa09457a 100644
> --- a/hw/ppc/amigaone.c
> +++ b/hw/ppc/amigaone.c
> @@ -36,10 +36,19 @@
>  * -device VGA,romfile=VGABIOS-lgpl-latest.bin
>  * from http://www.nongnu.org/vgabios/ instead.
>  */
> -#define PROM_FILENAME "u-boot-amigaone.bin"
> #define PROM_ADDR 0xfff00000
> #define PROM_SIZE (512 * KiB)
>
> +/* AmigaOS calls this routine from ROM, use this if no firmware loaded */
> +static const char dummy_fw[] = {
> +    0x38, 0x00, 0x00, 0x08, /* li      r0,8 */
> +    0x7c, 0x09, 0x03, 0xa6, /* mtctr   r0 */
> +    0x54, 0x63, 0xf8, 0x7e, /* srwi    r3,r3,1 */
> +    0x42, 0x00, 0xff, 0xfc, /* bdnz    0x8 */
> +    0x7c, 0x63, 0x18, 0xf8, /* not     r3,r3 */
> +    0x4e, 0x80, 0x00, 0x20, /* blr */
> +};
> +
> static void amigaone_cpu_reset(void *opaque)
> {
>     PowerPCCPU *cpu = opaque;
> @@ -60,8 +69,6 @@ static void amigaone_init(MachineState *machine)
>     PowerPCCPU *cpu;
>     CPUPPCState *env;
>     MemoryRegion *rom, *pci_mem, *mr;
> -    const char *fwname = machine->firmware ?: PROM_FILENAME;
> -    char *filename;
>     ssize_t sz;
>     PCIBus *pci_bus;
>     Object *via;
> @@ -94,20 +101,24 @@ static void amigaone_init(MachineState *machine)
>     }
>
>     /* allocate and load firmware */
> -    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, fwname);
> -    if (filename) {
> -        rom = g_new(MemoryRegion, 1);
> -        memory_region_init_rom(rom, NULL, "rom", PROM_SIZE, &error_fatal);
> -        memory_region_add_subregion(get_system_memory(), PROM_ADDR, rom);
> +    rom = g_new(MemoryRegion, 1);
> +    memory_region_init_rom(rom, NULL, "rom", PROM_SIZE, &error_fatal);
> +    memory_region_add_subregion(get_system_memory(), PROM_ADDR, rom);
> +    if (!machine->firmware) {
> +        rom_add_blob_fixed("dummy-fw", dummy_fw, sizeof(dummy_fw),
> +                           PROM_ADDR + PROM_SIZE - 0x80);
> +    } else {
> +        g_autofree char *filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
> +                                                   machine->firmware);
> +        if (!filename) {
> +            error_report("Could not find firmware '%s'", machine->firmware);
> +            exit(1);
> +        }
>         sz = load_image_targphys(filename, PROM_ADDR, PROM_SIZE);
>         if (sz <= 0 || sz > PROM_SIZE) {
>             error_report("Could not load firmware '%s'", filename);
>             exit(1);
>         }
> -        g_free(filename);
> -    } else if (!qtest_enabled()) {
> -        error_report("Could not find firmware '%s'", fwname);
> -        exit(1);
>     }
>
>     /* Articia S */