LinuxBIOS debugging with an emulator

Stephen.Kimball at Stephen.Kimball at
Fri Oct 29 16:35:00 CEST 2004

> On Thu, 2004-10-28 at 16:03, Stephen.Kimball at wrote:
> > 
> > It seems that LinuxBIOS copies itself to _RAMBASE, which is 0x4000.
> > Then it branches to 0x4000 into _start, which sets up the stack and
> > calls hardwaremain.  The address of hardwaremain from linuxbios_c.o
> > wrong.  The address is not the Flash address and it's not the RAM
> > address.  Can someone explain how linuxbios_c.o is linked with RAM
> > addresses?  
> > 
> What do you mean ? In the S2885 I built, the _RAMBASE is 0x4000 and 
> hardwaremain is 0x5fe0 as you can get from the They
> are both in RAM. If you use "objdump -drS linuxbios_c.o" you will
> find the hardwaremain is at offset 0x1fe0 from the _RAMBASSE.
> BTW, if you specify the -g option for gcc, you can use the -S option
> in objdump to see the source code with the disassebmly (-d).
> Ollie

In the amd/serenade I built, the _RAMBASE is 0x4000 and hardwaremain is
at 0x60B8 from the  Hardwaremain is at 0x20B8 in the
That all make sense.  But if I step through the execution of _start from
0x4000 to the call to hardwaremain.  I see it branch to 0x5F70 and the
instructions at 0x5F70 match the hardwaremain in objdump.  So I think
it's really at 0x5F70 not 0x60B8.  It's only off by 0x148 bytes.

I bet your hardwaremain isn't at 0x5FE0.


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