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author | Peter Tyser <ptyser@xes-inc.com> | 2010-04-12 22:28:04 -0500 |
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committer | Wolfgang Denk <wd@denx.de> | 2010-04-13 09:13:03 +0200 |
commit | ea0364f1bbfed1e3ea711147420875cf338fe77a (patch) | |
tree | 15c051bc4d2e94c1661c73e1b87c22c7beda7c24 /arch/i386/lib/realmode.c | |
parent | 89f39e177e7b0152aa1d3152baa25d986e36cdcf (diff) | |
download | u-boot-imx-ea0364f1bbfed1e3ea711147420875cf338fe77a.zip u-boot-imx-ea0364f1bbfed1e3ea711147420875cf338fe77a.tar.gz u-boot-imx-ea0364f1bbfed1e3ea711147420875cf338fe77a.tar.bz2 |
Move lib_$ARCH directories to arch/$ARCH/lib
Also move lib_$ARCH/config.mk to arch/$ARCH/config.mk
This change is intended to clean up the top-level directory structure
and more closely mimic Linux's directory organization.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Diffstat (limited to 'arch/i386/lib/realmode.c')
-rw-r--r-- | arch/i386/lib/realmode.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/i386/lib/realmode.c b/arch/i386/lib/realmode.c new file mode 100644 index 0000000..3c3c1fc --- /dev/null +++ b/arch/i386/lib/realmode.c @@ -0,0 +1,100 @@ +/* + * (C) Copyright 2002 + * Daniel Engström, 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 ulong _i386boot_realmode; +extern ulong _i386boot_realmode_size; +extern char realmode_enter; + +int realmode_setup(void) +{ + ulong i386boot_realmode = (ulong)&_i386boot_realmode; + ulong i386boot_realmode_size = (ulong)&_i386boot_realmode_size; + + /* 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, (REALMODE_MAILBOX-REALMODE_BASE)); + return -1; + } + + memcpy(REALMODE_BASE, (void*)i386boot_realmode, i386boot_realmode_size); + asm("wbinvd\n"); + + return 0; +} + +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; + } + + if (realmode_setup()) { + return -1; + } + + 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("wbinvd\n"); + + __asm__ volatile ( + "lcall $0x20,%0\n" : : "i" (&realmode_enter) ); + + asm("wbinvd\n"); + memcpy(out, REALMODE_MAILBOX, sizeof(struct pt_regs)); + + return out->eax; +} + + +/* This code is supposed to access a realmode interrupt + * it does currently not work for me */ +int enter_realmode_int(u8 lvl, struct pt_regs *in, struct pt_regs *out) +{ + /* place two instructions at 0x700 */ + writeb(0xcd, 0x700); /* int $lvl */ + writeb(lvl, 0x701); + writeb(0xcb, 0x702); /* lret */ + asm("wbinvd\n"); + + enter_realmode(0x00, 0x700, in, out); + + return out->eflags&1; +} |