Re: [coreboot] How can I call the interrupt of SeaBIOS in coreboot?

[Zhang Rui]

Hello,
    I am blocked with calling interrupt in coreboot.
    I tryed these ways:
    1. use "asm("int $0x19 \n");".  Qemu has no output when executeed
here and nothing happens. The reason is that it should jump to real
mode before calling int 19.

2. write a function boot_coreboot() in seabios. like:

void VISIBLE32 boot_coreboot()
    {
    	struct bregs br;
    	dprintf(1, "boot_coreboot: begin\n");
    	memset(&br, 0, sizeof(br));
    	dprintf(1, "boot_coreboot: call int 19\n");
    	call16_int(0x19, &br);
    	dprintf(1, "boot_coreboot: end\n");
    }
    
    then call boot_coreboot() in seabios. It booted successfully.

I have read the source code of call16_int, it jump to real mode and
jump to the int 19 handler function directly, but do not use "int
$0x19" asm code. why?

3. write asm code to jump to real mode and call int 19.
    but in coreboot there is compiling errors when I write asm codes with
lables in it in vm86.c.
    for a simple example:
    __asm__ __volatile__ (
    		/* paranoia -- does ecx get saved? not sure. This is
    		 * the easiest safe thing to do. */
    		"	pushal			\n"
    		"	ljmp 	$0x28, $cbint16bit\n"
    		"cbint16bit:		\n"
    		"	.code16			\n"
    		"	popal\n"
    		);

will cause errors:
    {standard input}: Assembler messages:
    {standard input}:746: Error: symbol `cbint16bit' is already defined
    
    in seabios there is compiling errors because of ".code16":
    out/../src/post.c:349: relocation truncated to fit: R_386_16 against `.text'

what is wrong here?

2008/7/17, Kevin O'Connor :
> On Thu, Jul 17, 2008 at 09:58:59AM +0800, Zhang Rui wrote:
> [...]
> > If I manually change to 16bit mode then call int19 in coreboot,  will it be OK?
> > If it does, the 16bit mode option rom codes can use the int handler of SeaBIOS?
>
> It should work.