On Tue, Sep 23, 2003 at 05:00:39PM -0600, ron minnich wrote:
> On Wed, 24 Sep 2003, SONE Takeshi wrote:
> > I saw an old version of my fixes to idt.c and vgabios.c is commited.
> > This version does not pass dev/busfn to the VGABIOS correctly.
> send me the fix. I thought this was the right one. Sorry.
Attached.
--
Takeshi
#include <string.h>
#include <printk.h>
// we had hoped to avoid this.
// this is a stub IDT only. It's main purpose is to ignore calls
// to the BIOS.
// no longer. Dammit. We have to respond to these.
struct realidt {
unsigned short offset, cs;
};
// from a handy writeup that andrey found.
// handler.
// There are some assumptions we can make here.
// First, the Top Of Stack (TOS) is located on the top of page zero.
// we can share this stack between real and protected mode.
// that simplifies a lot of things ...
// we'll just push all the registers on the stack as longwords,
// and pop to protected mode.
// second, since this only ever runs as part of linuxbios,
// we know all the segment register values -- so we don't save any.
// keep the handler that calls things small. It can do a call to
// more complex code in linuxbios itself. This helps a lot as we don't
// have to do address fixup in this little stub, and calls are absolute
// so the handler is relocatable.
void handler(void) {
__asm__ __volatile__ (
".code16\n"
"idthandle:\n"
" pushal\n"
" movb $0, %al\n"
" ljmp $0, $callbiosint16\n"
"end_idthandle:\n"
".code32\n"
);
}
// Calling conventions. The first C function is called with this stuff
// on the stack. They look like value parameters, but note that if you
// modify them they will go back to the INTx function modified.
// the C function will call the biosint function with these as
// REFERENCE parameters. In this way, we can easily get
// returns back to the INTx caller (i.e. vgabios)
void callbiosint(void) {
__asm__ __volatile__ (
".code16\n"
"callbiosint16:\n"
// clean up the int #. To save space we put it in the lower
// byte. But the top 24 bits are junk.
"andl $0xff, %eax\n"
// this push does two things:
// - put the INT # on the stack as a parameter
// - provides us with a temp for the %cr0 mods.
"pushl %eax\n"
"movl %cr0, %eax\n"
//"andl $0x7FFAFFD1, %eax\n" /* PG,AM,WP,NE,TS,EM,MP = 0 */
//"orl $0x60000001, %eax\n" /* CD, NW, PE = 1 */
"orl $0x00000001, %eax\n" /* PE = 1 */
"movl %eax, %cr0\n"
/* Now that we are in protected mode jump to a 32 bit code segment. */
"data32 ljmp $0x10, $biosprotect\n"
"biosprotect:\n"
".code32\n"
" movw $0x18, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
" mov %ax, %ss \n"
" call biosint \n"
// back to real mode ...
" ljmp $0x28, $__rms_16bit\n"
"__rms_16bit: \n"
".code16 \n" /* 16 bit code from here on... */
/* Load the segment registers w/ properly configured segment
* descriptors. They will retain these configurations (limits,
* writability, etc.) once protected mode is turned off. */
" mov $0x30, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
" mov %ax, %ss \n"
/* Turn off protection (bit 0 in CR0) */
" movl %cr0, %eax \n"
" andl $0xFFFFFFFE, %eax \n"
" movl %eax, %cr0 \n"
/* Now really going into real mode */
" ljmp $0, $__rms_real \n"
"__rms_real: \n"
/* Setup a stack */
" mov $0x0, %ax \n"
" mov %ax, %ss \n"
/* ebugging for RGM */
" mov $0x11, %al \n"
" outb %al, $0x80\n"
" xor %ax, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
// pop the INT # that you pushed earlier
" popl %eax\n"
" popal\n"
" iret\n"
".code32\n"
);
}
enum {
PCIBIOS = 0x1a,
MEMSIZE = 0x12
};
#ifdef CONFIG_PCIBIOS
int
pcibios(
unsigned long *pedi,
unsigned long *pesi,
unsigned long *pebp,
unsigned long *pesp,
unsigned long *pebx,
unsigned long *pedx,
unsigned long *pecx,
unsigned long *peax,
unsigned long *pflags
);
#endif
extern void vga_exit(void);
int
biosint(
unsigned long intnumber,
unsigned long edi,
unsigned long esi,
unsigned long ebp,
unsigned long esp,
unsigned long ebx,
unsigned long edx,
unsigned long ecx,
unsigned long eax,
unsigned long cs_ip,
unsigned short stackflags
) {
unsigned long ip;
unsigned long cs;
unsigned long flags;
int ret = -1;
ip = cs_ip & 0xffff;
cs = cs_ip >> 16;
flags = stackflags;
printk_debug("biosint: # 0x%lx, eax 0x%lx ebx 0x%lx ecx 0x%lx edx 0x%lx\n",
intnumber, eax, ebx, ecx, edx);
printk_debug("biosint: ebp 0x%lx esp 0x%lx edi 0x%lx esi 0x%lx\n", ebp, esp, edi, esi);
printk_debug("biosint: ip 0x%x cs 0x%x flags 0x%x\n", ip, cs, flags);
// cases in a good compiler are just as good as your own tables.
switch (intnumber) {
case 0 ... 15:
// These are not BIOS service, but the CPU-generated exceptions
printk_info("biosint: Oops, exception %u\n", intnumber);
if (esp < 0x1000) {
printk_debug("Stack contents: ");
while (esp < 0x1000) {
printk_debug("0x%04x ", *(unsigned short *) esp);
esp += 2;
}
printk_debug("\n");
}
printk_debug("biosint: Bailing out\n");
// Should be replaced by longjmp for generalization.
vga_exit();
break;
#ifdef CONFIG_PCIBIOS
case PCIBIOS:
ret = pcibios( &edi, &esi, &ebp, &esp,
&ebx, &edx, &ecx, &eax, &flags);
break;
#endif
case MEMSIZE:
// who cares.
eax = 64 * 1024;
ret = 0;
break;
default:
printk_info(__FUNCTION__ ": Unsupport int #0x%x\n",
intnumber);
break;
}
if (ret)
flags |= 1; // carry flags
else
flags &= ~1;
stackflags = flags;
return ret;
}
void
setup_realmode_idt(void) {
extern unsigned char idthandle, end_idthandle;
int i;
struct realidt *idts = (struct realidt *) 0;
int codesize = &end_idthandle - &idthandle;
unsigned char *intbyte, *codeptr;
// for each int, we create a customized little handler
// that just pushes %ax, puts the int # in %al,
// then calls the common interrupt handler.
// this necessitated because intel didn't know much about
// architecture when they did the 8086 (it shows)
// (hmm do they know anymore even now :-)
// obviously you can see I don't really care about memory
// efficiency. If I did I would probe back through the stack
// and get it that way. But that's really disgusting.
for (i = 0; i < 256; i++) {
idts[i].cs = 0;
codeptr = (char*) 4096 + i * codesize;
idts[i].offset = (unsigned) codeptr;
memcpy(codeptr, &idthandle, codesize);
intbyte = codeptr + 3;
*intbyte = i;
}
// Support for fixed entry points
// First off, fill 0xCC (breakpoint) from f000:e000 to f000:ffff
// so we can catch the calls to unimplemented entry points.
// This 8KB area is where the fixed entry points are at.
// Maybe the original IBM PC had only this much of ROM.
memset((void *) 0xfe000, 0xCC, 0x2000);
// VGA BIOSes tend to hardcode f000:f065 as the default handler for
// int10.
// calling convention here is the same as INTs, we can reuse
// the int entry code.
codeptr = (char*) 0xff065;
memcpy(codeptr, &idthandle, codesize);
intbyte = codeptr + 3;
*intbyte = 0x42; /* int42 is the relocated int10 */
// Clear the BIOS Data Area, not to confuse the realmode code.
memset((void *) 0x400, 0, 0x100);
}
#ifndef lint
static char rcsid[] = "$Id: vgabios.c,v 1.9 2003/09/08 20:10:45 rminnich Exp $";
#endif
#include <pci.h>
#include <pci_ids.h>
#undef __KERNEL__
#include <arch/io.h>
#include <printk.h>
#include <string.h>
/* vgabios.c. Derived from: */
/*------------------------------------------------------------ -*- C -*-
* 2 Kernel Monte a.k.a. Linux loading Linux on x86
*
* Erik Arjan Hendriks <[EMAIL PROTECTED]>
*
* This version is a derivative of the original two kernel monte
* which is (C) 2000 Scyld.
*
* Copyright (C) 2000 Scyld Computing Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Portions related to the alpha architecture are:
*
* Copyright(C) 2001 University of California. LA-CC Number 01-67.
* This software has been authored by an employee or employees of the
* University of California, operator of the Los Alamos National
* Laboratory under Contract No. W-7405-ENG-36 with the U.S.
* Department of Energy. The U.S. Government has rights to use,
* reproduce, and distribute this software. If the software is
* modified to produce derivative works, such modified software should
* be clearly marked, so as not to confuse it with the version
* available from LANL.
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by
* reference to http://www.gnu.org/licenses/gpl.html.
*
* This software is provided by the author(s) "as is" and any express
* or implied warranties, including, but not limited to, the implied
* warranties of merchantability and fitness for a particular purpose
* are disclaimed. In no event shall the author(s) be liable for any
* direct, indirect, incidental, special, exemplary, or consequential
* damages (including, but not limited to, procurement of substitute
* goods or services; loss of use, data, or profits; or business
* interruption) however caused and on any theory of liability,
* whether in contract, strict liability, or tort (including
* negligence or otherwise) arising in any way out of the use of this
* software, even if advised of the possibility of such damage.
*
* $Id: vgabios.c,v 1.9 2003/09/08 20:10:45 rminnich Exp $
*--------------------------------------------------------------------*/
#if (CONFIG_VGABIOS == 1)
extern void real_mode_switch_call_vga(unsigned long busdevfn);
__asm__ (
".text\n"
"__stack:\n"
" .long 0\n"
"real_mode_switch_call_vga:\n"
" pushl %ebp\n"
" movl %esp, %ebp\n"
/* Save callee-saved registers, since we don't know what VGABIOS would break */
" pushl %ebx\n"
" pushl %esi\n"
" pushl %edi\n"
/* Get busdevfn in %ecx */
" movl 8(%ebp), %ecx\n"
/* Save the stack */
" mov %esp, __stack\n"
/* This configures CS properly for real mode. */
" ljmp $0x28, $1f\n"
"1:\n"
".code16\n" /* 16 bit code from here on... */
/* Load the segment registers w/ properly configured segment
* descriptors. They will retain these configurations (limits,
* writability, etc.) once protected mode is turned off. */
" movw $0x30, %ax\n"
" movw %ax, %ds\n"
" movw %ax, %es\n"
" movw %ax, %fs\n"
" movw %ax, %gs\n"
" movw %ax, %ss\n"
/* Turn off protection (bit 0 in CR0) */
" movl %cr0, %eax\n"
" andl $0xFFFFFFFE, %eax\n"
" movl %eax, %cr0\n"
/* Now really going into real mode */
" ljmp $0, $1f\n"
"1:\n"
// put the stack at the end of page zero.
// that way we can easily share it between real and protected,
// since the 16-bit ESP at segment 0 will work for any case.
/* Setup a stack */
" xorw %ax, %ax\n"
" movw %ax, %ss\n"
" movl $0x1000, %esp\n"
/* debugging for RGM */
" movb $0x11, %al\n"
" outb %al, $0x80\n"
/* Dump zeros in the other segregs */
" xorw %ax, %ax\n"
" movw %ax, %ds\n"
" movw %ax, %es\n"
" movw %ax, %fs\n"
" movw %ax, %gs\n"
/* Set bus/devfn to %ax */
" movw %cx, %ax\n"
/* Now do the deed */
" lcallw $0xc000, $0x0003\n"
/* debugging for RGM */
" movb $0x55, %al\n"
" outb %al, $0x80\n"
/* if we got here, just about done.
* Need to get back to protected mode */
" movl %cr0, %eax\n"
" orl $0x0000001, %eax\n" /* PE = 1 */
" movl %eax, %cr0\n"
/* Now that we are in protected mode jump to a 32 bit code segment. */
" ljmpl $0x10, $1f\n"
"1:\n"
".code32\n"
" movw $0x18, %ax\n"
" movw %ax, %ds\n"
" movw %ax, %es\n"
" movw %ax, %fs\n"
" movw %ax, %gs\n"
" movw %ax, %ss\n"
/* Emergency exit */
".globl vga_exit\n"
"vga_exit:\n"
" movl __stack, %esp\n"
" popl %edi\n"
" popl %esi\n"
" popl %ebx\n"
" popl %ebp\n"
" ret\n"
);
void
do_vgabios(void)
{
struct pci_dev *dev;
unsigned long busdevfn;
unsigned int rom = 0;
unsigned char *buf;
unsigned int size = 64*1024;
int i;
dev = pci_find_class(PCI_CLASS_DISPLAY_VGA <<8, NULL);
if (! dev) {
printk_debug("NO VGA FOUND\n");
return;
}
printk_debug("found VGA: vid=%x, did=%x\n", dev->vendor, dev->device);
#ifdef VGABIOS_START
// Use VGA BIOS blob at specified address
rom = VGABIOS_START;
#else
pci_read_config_dword(dev, PCI_ROM_ADDRESS, &rom);
// paranoia
rom = 0xf0000000;
pci_write_config_dword(dev, PCI_ROM_ADDRESS, rom|1);
printk_debug("rom base, size: %x\n", rom);
#endif
buf = (unsigned char *) rom;
if ((buf[0] == 0x55) && (buf[1] == 0xaa)) {
memcpy((void *) 0xc0000, buf, size);
for(i = 0; i < 16; i++)
printk_debug("0x%x ", buf[i]);
// check signature again
buf = (unsigned char *) 0xc0000;
if (buf[0]==0x55 && buf[1]==0xAA) {
busdevfn = (dev->bus->secondary << 8) | dev->devfn;
printk_debug("bus/devfn = %#x\n", busdevfn);
real_mode_switch_call_vga(busdevfn);
} else
printk_debug("Failed to copy VGA BIOS to 0xc0000\n");
} else
printk_debug("BAD SIGNATURE 0x%x 0x%x\n", buf[0], buf[1]);
#ifndef VGABIOS_START
pci_write_config_dword(dev, PCI_ROM_ADDRESS, 0);
#endif
}
#endif // (CONFIG_VGABIOS == 1)
