Thanks for the reply however as my boss was sat watching me I wound up taking
another direction.
Because I knew the address of the block of RAM and the name I was calling it
with I was able to create a block. Instead of using malloc to allocate the
memory for it, I set the address for the RAM to the address of the external
block I'd created meaning that all the standard RAM functions should work :)
When I have some time I'll have to try creating and using ROMD
>-----Original Message-----
>From: Blue Swirl [mailto:blauwir...@gmail.com]
>Sent: 01 September 2012 10:26
>To: Brian Roantree
>Cc: qemu-devel@nongnu.org
>Subject: Re: [Qemu-devel] External RAM
>On Wed, Aug 29, 2012 at 1:38 PM, Brian Roantree <brian.roant...@imgtec.com>
>wrote:
>> Hi, I’m not sure which list this belongs in and was unable to find
>> anything like it so here goes,
>>
>>
>>
>> I am using QEMU 0.15.90 to emulate a processor and have currently got
>> it running in a loosely timed simulation with a systemC kernel as
>> well, I have also created and attached a block of RAM as well as
>> another device and am running into a problem. It is registered as IO
>> memory and replaced the generic internal ram that was allocated using
>> qemu_ram_alloc, the problem I’m having is that my bootloader is now
>> trying to write to RAM address
>> 4293918720 (0xFFF00000) which doesn’t exist. My question is can I
>> somehow use qemu_ram_alloc to allocate the RAM but still use the
>> different IO functions to read and write from this block of memory?
>>
>>
>>
>> I have tried creating a device for the ram and after initialising it
>> using
>>
>>
>>
>> Addr = qemu_ram_alloc(s->sc_shared_ram,”name.ram”, ram_size);
>>
>> cpu_register_physical_memory(addr_base, ram_size, Addr);
>>
>> where s is processor device_state and sc_shared_ram is a device_state
>> with the modified read and write functions
>>
>>
>>
>> however when the Ram is used the read and write functions are never
>> employed.
>>
>>
>>
>> Any help you could provide would be much appreciated, also apologies
>> if I’m not that clear with my wording I haven’t been doing QEMU
>> development that long so am not also sure how to express what I want. >
>Either the memory is registered as MMIO (but then it's not possible to execute
>code from it), or it's registered as RAM (but then it's not possible to
>register MMIO handlers). In between those, >there's ROMD, which is read as RAM
>but written as MMIO device.
