Booting VxWorks from LinuxBios

[Christopher Stutts]

On Wed, 2003-02-05 at 12:16, Felix Radensky wrote:
> Hi, Christopher
> 
> Thanks a lot for the code. I really appreciate it !
> Did you modify the linuxbios itself to allow VxWorks
> to be loaded at 8000h. I guess I have to modify ldscript.ld
> but i don't know how.
> 
> Thanks a lot.
> 
> Felix.

Two years ago(?), working from an old tarball on a 430TX-based board, I
threw the quoted C code in where the jump to the linux kernel normally
goes, and apparently I modified the GDT as well.  The experiment
convinced us to go this route for our PIII BX board running a different
RTOS instead of buying a BIOS solely for its SDRAM init, pci
enumeration, & disk boot capabilities.  

If there is a cleaner switch to real mode available now, use it.  (You
can see that I was patching code in ram in order to jump to a 16-bit
protected mode segment, and that the chipset wasn't entirely
cooperating.) You might also look to see if there is a protected mode
entry point to your vxWorks code.  I don't know if that is feasible or
not.  We haven't done vxWorks for 2 years, and only a couple printed
manuals were saved from the Great Purge.  

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