Re: [Qemu-devel] Qemu as Instruction Set Simulator without any OS

[Anitha Boyapati <anitha.boyapati@gmail.com>]

On 1 September 2010 19:22, Robin Randhawa <robin.randhawa@gmail.com> wrote:
[...]
>> My exact requirement is to test a gcc cross-compiler using DejaGnu for
>> a given target (AVR32). While the cross-compiler is ready, there is no
>> simulator. Since there is not much of OS support, I am trying to
>> evaluate if Qemu can still be considered for this purpose.
>
> I see. That makes sense. I thought that AVR32 support never made it to
> the mainline. Has that changed ?
>

Not yet. Maybe sooner :-)

>> The usage scenario probably goes like this:
>>
>> 1. Qemu-target should be invoked with the application (yes,
>> bare-metal) waiting for some gdb connection.  2. target-gdb is invoked
>> with the same application
>>
>> I am referring to the example given in
>> http://wiki.qemu.org/download/qemu-doc.html#gdb_005fusage :
>>
>> > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append
>> > "root=/dev/hda"
>>
>> However, in my case kernel image doesn't exist.
>
> Got that. Note that your system mode emulation would have to cater for
> loading the bare-metal image (qemu has well defined APIs for this). Some
> emulations add some intelligence over and above the bare-metal image
> loading, such as the ARM Realview emulation which checks to see if the
> image passed to the "-kernel" argument is a Linux image in which case
> some special case initialisation is done (instead of a 'raw' load).
>

I was thinking along similar lines. Little more source code probing
should give me better overview.

>> As to the requirement
>> of bootloader, I need to investigate further as various types of
>> memories (FLASH & SRAM for program and data sections) exist.
>
> Most of that can be easily faked as simple RAM at the appropriate
> offsets in your platform description to start off with.
>

Yep, I hope so. Thanks for the help :-)

Best Regards
Anitha