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

[BALATON Zoltan <balaton@eik.bme.hu>]

On Thu, 30 Nov 2023, BALATON Zoltan wrote:
> 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.

Just seen message from maintainer that picked v3 on purpose as this was 
already tested. As it also works v4 just simplifies it it's OK then to 
merge this. Sorry for the noise.

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 */
>> 
>
>