PXA255 QEM FYI

Mark Tinguely tinguely at casselton.net
Thu Mar 19 10:54:34 PDT 2009


on Thu, 19 Mar 2009 10:46:20 -0600 (MDT), M. Warner Losh replied:

>              Mark Tinguely <tinguely at casselton.net> writes:
>  : A simple work around in FreeBSD would something like:
>  : static int
>  : uart_pxa_probe(device_t dev)
	<trimmed>
>  : +#ifdef QEMU

>  Should the PXA emulation be fixed in qemu?

I will bring it to qemu developers' attention. If it is alright with the
FreeBSD ARM group, I could ask if they would raise the UART Unit Enable (UUE)
bit on the Interrupt Enable Register (IER) when activating a UART in emulation.
Worst they can do is say no.

>  : 2) the new QEMU (qemu-0.10.0_1) compile under FreeBSD-8.0-current, incorrect
>  : brings a register value from the ARM enviroment to the QEMU SMC emulation
>  : evironment and QEMU crashes with a message:
>  : 
>  : qemu: fatal: smc91c111_read: Bad reg 0:30e
>  : 
>  : R00=00000000 R01=c5e1f300 R02=0000000e R03=c0a778e0
>  : R04=c0ba8300 R05=c0baab00 R06=00000003 R07=00000001
>  : R08=00000000 R09=00000000 R10=c0bb4540 R11=c00fbc50
>  : R12=c00fbc54 R13=c00fbc44 R14=c0403950 R15=c03e8bac
>  : PSR=a0000113 N-C- A svc32
>  : 
>  : Notice register 2 has the correct value of 0x0e.
>  : 
>  : Compiled under FreeBSD 6.4, the emulator runs fine. I will mention this
>  : to the QEMU people; it may be a difference in gcc3 vs gcc4. A temporary
>  : work around in QEMU might be a mask (0xff) of the offset variable in
>  : smc91c111_readb (and smc91c111_writeb ?) or removal of the ethernet card
>  : from the kernel configuration.
>
>  Hmmm...  That's a good question...  I'd talk with them, since stuff
>  like that shouldn't be needed.

I will send them this trace with a OS and compiler information.

--Mark.


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