Re: riscv virt target write pflash

[Philippe Mathieu-Daudé]

Cc'ing qemu-riscv mailing list which is more focused.

On 18/2/24 22:32, max wrote:
> I am relatively new to QEMU so I hope that this is the right place to ask:
>
> I tried starting QEMU with the following command:
> ```
> qemu-system-riscv64 -M virt -drive 
> if=pflash,format=raw,unit=0,file=bios.rom -m 512M -nographic -s -S
> ```
>
> I am using GDB to debug the `bios.rom` Firmware. At some point in the 
> execution `bios.rom` writes into some global variable (at 0x2000525C) 
> inside the .bss section which is linked to be inside the memory mapped 
> pflash0. But when I step forward with GDB to the exact location where 
> the store instruction (sw) is executed, QEMU prints the following:
> ```
> pflash_write: Unimplemented flash cmd sequence (offset 000000000000525c, 
> wcycle 0x0 cmd 0x0 value 0x1)
> ```
> According to the top of `hw/block/pflash_cfi01.c` Flash writes are 
> supported. I am probably missing something here so it would be nice if 
> someone could point me in the right direction. I would also gladly 
> contribute if there is something missing in the riscv virt target.