Re: [Qemu-devel] [PATCH] SH4: SCI improvement

[Shin-ichiro KAWASAKI]

Hi, Jean-san!

It seems a good idea to make u-boot run on SH4-QEMU,
for brushing up SH4 emulation.

Jean-Christophe PLAGNIOL-VILLARD wrote:
>         I've add the flash support at 0xA0000000
>         and have qemu refusing to boot from it
>         qemu: fatal: Trying to execute code outside RAM or ROM at 0xa000000A

>         I've also try to boot u-boot as a kernel and have the output working
>         but not the input. Impossible to type anything

I'm afraid that I have no idea about these two points now.
I just guess MMU emulation and SCIF emulation might not be enough to run u-boot.

To investigate them more closely, I downloaded current u-boot git repository,
build if for r2d, and run u-boot.bin with -kernel option.  But u-boot couldn't
boot with assertion failures.  Following two parts caused them.

- MMUCR initialization with 16 bit word write causes failure.
  QEMU only implements 32 bit write for it, following SH7750 document.
- BSC's PCR access cause failure. 
  QEMU does not implement it yet.

Have you handled them?


Regards,
Shin-ichiro KAWASAKI



> U-Boot 2008.10-00237-g6d56cf3 (Nov 23 2008 - 21:08:17)
>
> CPU: SH4
> BOARD: Renesas Solutions R2D Plus
> DRAM:  64MB
> Timer with period zero, disabling
> ## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB
> FLASH: 0MB
> *** Warning - bad CRC, using default environment
>
> In:    serial
> Out:   serial
> Err:   serial
> Net:   No ethernet found.
> => 
>
> Best Regards,
> J.