On 23-Jul-01 Weiguang SHI wrote:
> Thanks.
> I think I've found it in btx.s:
>
> 213 mov %eax,%cr0 #
> 214 ljmp $SEL_SCODE,$init.8 # To 32-bit code
> 215 .code32
> 216 init.8: xorl %ecx,%ecx # Zero
>
> And there IS this "ljmp".
Yes.
> Well, this BTX thing is amazing: all this effort, (btxld, run-time
> library crt0.o, loader, etc.) seems to just to provide a 32-bit
> protected and possibly paging-enabled environment to start the
> kernel/loader(and to confuse a new-comer like me.) What are the
> other gains? Where can I found more info about this BTX before going
> through the ultimate source code? (I've search the mailing-lists.)
That's its purpose, to provide a mini-kenrel for the loader so we can write the
loader in C and not assembly. (gcc doesn't do well with generating code for
real mode).
--
John Baldwin <[EMAIL PROTECTED]> -- http://www.FreeBSD.org/~jhb/
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