[coreboot] option rom size problem

Leandro Dorileo ldorileo at gmail.com
Mon Jul 20 19:12:40 CEST 2009

Hi Carl

On Mon, Jul 20, 2009 at 12:48 PM, Carl-Daniel
Hailfinger<c-d.hailfinger.devel.2006 at gmx.net> wrote:
> On 20.07.2009 17:54, Stefan Reinauer wrote:
>> On 20.07.2009 17:40 Uhr, Jason Wang wrote:
>>>    Since i am working with adding libpayload usb stack to option rom,
>>> i have been blocked with the usb_initialize function. I find that the
>>> size of libpayload is 104K, but the max size of option rom is oxff *
>>> 512bytes. which means 127.5K.
>>> I am afraid our option rom can not works fine with usb stack properly.
>>> Is there any other method for us to expand the rom size?
>> I think only those parts of libpayload that are actually used are
>> getting linked into the final binary,  since the objects are packed into
>> an "ar" archive. Do you exceed the rom size with libpayload and your
>> code already, or is this rather a theoretical issue?
> If you really exceed the allowed size, the problem is not only option
> rom size but also where in RAM you can place that much code.
> Compression can help if you have enough free RAM to place that option
> ROM somewhere.

Do you mean we can have a code to decompress the option ROM and jump to it?

> Where does the option ROM end up? Below 1M?

Do you mean in RAM? do you want to know when we move the option ROM to
RAM? if so, I can tell you that we are not moving the option ROM to
RAM,  we leave it to seabios, seabios is who moves the ROM code to


(°=   Leandro Dorileo
//\    ldorileo at gmail.com   -   http://www.dorilex.net
V_/  Software is a matter of freedom.

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