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

[Shin-ichiro KAWASAKI <kawasaki@juno.dti.ne.jp>]

Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 13:39 Mon 24 Nov     , Shin-ichiro KAWASAKI wrote:
>> 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?
>>
> you need to apply 1 patch on u-boot
> 
> r2dplus fix register access
> I've send to the U-Boot ML
> 
> and 2 patchs to qemu
> 
>>From you
> sh4: pci and mmu support
> and from I
> SH7750/51: add register BCR3, NCR4, PCR, RTCOR, RTCNT, RTCSR, SDMR2, SDMR3 and
> fix BCR2 support

Thanks.

One more simple modification seems necessary to avoid assertion error,
as attached to this mail.  With these patches, I saw that the U-boot
for r2dplus boots cleanly when it is passed with -kernel option to qemu.
Does it help you?
# Please be sure to give two '-serial' options in qemu command line.

I'm interested in the flash support, which will make it more easy
to handle linux kernel boot conditions for qemu-sh users.

Regards,
Shin-ichiro KAWASAKI


diff --git a/hw/sh_serial.c b/hw/sh_serial.c
index da1a2ca..bf1d609 100644
--- a/hw/sh_serial.c
+++ b/hw/sh_serial.c
@@ -242,11 +242,9 @@ static uint32_t sh_serial_ioport_read(void *opaque, uint32_t offs)
                     s->flags &= ~SH_SERIAL_FLAG_RDF;
             }
             break;
-#if 0
         case 0x18:
             ret = s->fcr;
             break;
-#endif
         case 0x1c:
             ret = s->rx_cnt;
             break;