|
|
|
|
|
/*
|
|
|
|
|
|
* (C) Copyright 2002
|
|
|
|
|
|
* Daniel Engstr<EFBFBD>m, Omicron Ceti AB, daniel@omicron.se
|
|
|
|
|
|
*
|
|
|
|
|
|
* See file CREDITS for list of people who contributed to this
|
|
|
|
|
|
* project.
|
|
|
|
|
|
*
|
|
|
|
|
|
* 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
|
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
#include <common.h>
|
|
|
|
|
|
#include <asm/io.h>
|
|
|
|
|
|
#include <asm/ptrace.h>
|
|
|
|
|
|
#include <asm/realmode.h>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#define REALMODE_BASE ((char*)0x7c0)
|
|
|
|
|
|
#define REALMODE_MAILBOX ((char*)0xe00)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
extern char realmode_enter;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
int enter_realmode(u16 seg, u16 off, struct pt_regs *in, struct pt_regs *out)
|
|
|
|
|
|
{
|
|
|
|
|
|
|
|
|
|
|
|
/* setup out thin bios emulation */
|
|
|
|
|
|
if (bios_setup()) {
|
|
|
|
|
|
return -1;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* copy the realmode switch code */
|
|
|
|
|
|
if (i386boot_realmode_size > (REALMODE_MAILBOX-REALMODE_BASE)) {
|
|
|
|
|
|
printf("realmode switch too large (%ld bytes, max is %d)\n",
|
|
|
|
|
|
i386boot_realmode_size, (int)(REALMODE_MAILBOX-REALMODE_BASE));
|
|
|
|
|
|
return -1;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
memcpy(REALMODE_BASE, (void*)i386boot_realmode, i386boot_realmode_size);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
in->eip = off;
|
|
|
|
|
|
in->xcs = seg;
|
|
|
|
|
|
if (3>(in->esp & 0xffff)) {
|
|
|
|
|
|
printf("Warning: entering realmode with sp < 4 will fail\n");
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
memcpy(REALMODE_MAILBOX, in, sizeof(struct pt_regs));
|
|
|
|
|
|
|
|
|
|
|
|
__asm__ volatile (
|
|
|
|
|
|
"lcall $0x20,%0\n" : : "i" (&realmode_enter) );
|
|
|
|
|
|
|
|
|
|
|
|
memcpy(out, REALMODE_MAILBOX, sizeof(struct pt_regs));
|
|
|
|
|
|
|
|
|
|
|
|
return out->eax;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
