Re: [Etherboot-developers] Q: does xstart work?

[Eric W B. <ebi...@ln...>]

ke...@us... (Ken Yap) writes:

> >> > _execaddr is filled in with a linear address.
> >
> >My best guess is that the ADDR32 prefix is just ignored somewhere.
> >As a linear address doesn't make any sense in 16bit real mode.
> 
> But it's in 32-bit PM at that point.

Hmm.  The LJMPI sure looks like it is in 32PM to me....
xstart:
	pushl	%ebp
	movl	%esp,%ebp
	pushl	%ebx
	pushl	%esi
	pushl	%edi
	movl	8(%ebp),%eax
	movl	%eax,_execaddr
	movl	12(%ebp),%ebx
	movl	16(%ebp),%ecx	/* bootp record (32bit pointer) */
	shll	$12,%ecx	/* convert to segment:offset form */
	shrw	$12,%cx
	call	_prot_to_real
	.code16
	pushl	%ecx		/* bootp record */
	pushl	%ebx		/* file header */
	movl	$((RELOC<<12)+(1f-RELOC)),%eax
	pushl	%eax
	ADDR32	LJMPI(_execaddr-_start)
1:
	addw	$8,%sp		/* XXX or is this 10 in case of a 16bit "ret" */
	DATA32 call	_real_to_prot
	.code32
	popl	%edi
	popl	%esi
	popl	%ebx
	popl	%ebp
	ret

_execaddr:
	.long	0



Eric