[coreboot] r613 - in coreboot-v3: northbridge/amd/geodelx util/x86emu
svn at coreboot.org
svn at coreboot.org
Thu Feb 21 06:20:14 CET 2008
Author: rminnich
Date: 2008-02-21 06:20:14 +0100 (Thu, 21 Feb 2008)
New Revision: 613
Added:
coreboot-v3/util/x86emu/vm86_gdt.c
Modified:
coreboot-v3/northbridge/amd/geodelx/Makefile
coreboot-v3/northbridge/amd/geodelx/geodelx.c
coreboot-v3/northbridge/amd/geodelx/vsmsetup.c
coreboot-v3/util/x86emu/Makefile
coreboot-v3/util/x86emu/vm86.c
Log:
This discussion is too useful to lose.
Carl-Daniel Hailfinger wrote:
> On 18.02.2008 23:55, Marc Jones wrote:
>> Carl-Daniel Hailfinger wrote:
>>> it seems that executing VSA requires vm86 to be useful. Since we
>>> unconditionally execute the VSA, we should unconditionally require
vm86
>>> support (PCI_OPTION_ROM_RUN_VM86) via Kconfig for Geode targets. Not
>>> doing so will either cause compile failures or runtime failures.
>>>
>>> Adding
>>> select PCI_OPTION_ROM_RUN_VM86
>>> below
>>> config CPU_AMD_GEODELX
>>> did not work out for me.
>> Sorry I missed this.
>>
>> VSA requires the GDT that is in vm86.c. VSA loads similar to an
option
>> ROM so the loader does go into VM86 mode. All the other stuff like
>> interrupt support and PCI BIOS isn't needed by VSA. I think that the
>> GDT at the top of vm86.c can be moved to a header file, gdt.h or
>> something like that.
>
> northbridge/amd/geodelx/vsmsetup.c uses
> util/x86emu/vm86.c:setup_realmode_idt() but it seems most/all of the
> setup there is not needed at all for VSA. Pulling in
setup_realmode_idt
> pulls in the rest of vm86 through direct and indirect dependencies.
>
>> Care to make a patch? :)
>
I am also leaning towards removing the IDT for VSA init. There is a risk
if either an exception happens or a software interrupt is used you will
get unexpected results. What probably happens is that you jump off to
something that will eventually cause a triple fault and reboot. You may
think this is bad (and it is) but it is the same risk that coreboot runs
today. If coreboot had a generic IDT to handle exceptions, VSA init
would use the same IDT. Note that hardware INT (even timers) should
never happen as they are always masked.
I have built with no PCI_OPTION_ROM_RUN_VM86 and run this to filo.
- Show quoted text -
Marc
--
Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com
http://www.amd.com/embeddedprocessors
Reduce the amount of compilation errors for Geode LX targets if x86emu
or no emulation is selected instead of vm86.
Factor out GDT code from vm86.c to vm86_gdt.c
Remove IDT setup for VSA init.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net>
Signed-of-by: Marc Jones <marc.jones at amd.com>
This has booted to runlevel 3 and the ethernet works fine.
Acked-by: Ronald G. Minnich <rminnich at gmail.com>
Modified: coreboot-v3/northbridge/amd/geodelx/Makefile
===================================================================
--- coreboot-v3/northbridge/amd/geodelx/Makefile 2008-02-20 13:33:36 UTC (rev 612)
+++ coreboot-v3/northbridge/amd/geodelx/Makefile 2008-02-21 05:20:14 UTC (rev 613)
@@ -22,6 +22,7 @@
ifeq ($(CONFIG_NORTHBRIDGE_AMD_GEODELX),y)
STAGE2_CHIPSET_OBJ += $(obj)/northbridge/amd/geodelx/geodelx.o \
- $(obj)/northbridge/amd/geodelx/vsmsetup.o
+ $(obj)/northbridge/amd/geodelx/vsmsetup.o \
+ $(obj)/util/x86emu/vm86_gdt.o
endif
Modified: coreboot-v3/northbridge/amd/geodelx/geodelx.c
===================================================================
--- coreboot-v3/northbridge/amd/geodelx/geodelx.c 2008-02-20 13:33:36 UTC (rev 612)
+++ coreboot-v3/northbridge/amd/geodelx/geodelx.c 2008-02-21 05:20:14 UTC (rev 613)
@@ -30,7 +30,6 @@
extern void chipsetinit(void);
extern u32 get_systop(void);
extern void northbridge_init_early(void);
-extern void setup_realmode_idt(void);
/**
@@ -155,8 +154,6 @@
// northbridge_init_early();
chipsetinit();
- setup_realmode_idt();
-
printk(BIOS_SPEW, "Before VSA:\n");
/* print_conf(); */
/* Do the magic stuff here, so prepare your tambourine ;) */
Modified: coreboot-v3/northbridge/amd/geodelx/vsmsetup.c
===================================================================
--- coreboot-v3/northbridge/amd/geodelx/vsmsetup.c 2008-02-20 13:33:36 UTC (rev 612)
+++ coreboot-v3/northbridge/amd/geodelx/vsmsetup.c 2008-02-21 05:20:14 UTC (rev 613)
@@ -89,10 +89,6 @@
" mov %%ax, %%ss \n"
" movl $0x1000, %%eax \n"
" movl %%eax, %%esp \n"
- /* Load our 16 it idt */
- " xor %%ax, %%ax \n"
- " mov %%ax, %%ds \n"
- " lidt __myidt \n"
/* Dump zeros in the other segregs */
" mov %%ax, %%es \n"
/* FixMe: Big real mode for gs, fs? */
@@ -120,9 +116,8 @@
" mov %%ax, %%fs \n"
" mov %%ax, %%gs \n"
" mov %%ax, %%ss \n"
- /* restore proper gdt and idt */
+ /* restore proper gdt */
" lgdt %%cs:gdtarg \n"
- " lidt idtarg \n"
".globl vsm_exit \n"
"vsm_exit: \n"
" mov __stack, %%esp \n"
Modified: coreboot-v3/util/x86emu/Makefile
===================================================================
--- coreboot-v3/util/x86emu/Makefile 2008-02-20 13:33:36 UTC (rev 612)
+++ coreboot-v3/util/x86emu/Makefile 2008-02-21 05:20:14 UTC (rev 613)
@@ -20,7 +20,7 @@
X86EMU_OBJ = debug.o decode.o fpu.o ops.o ops2.o prim_ops.o sys.o
BIOSEMU_OBJ = biosemu.o pcbios/pcibios.o
-VM86_OBJ = vm86.o
+VM86_OBJ = vm86.o vm86_gdt.o
ifeq ($(CONFIG_PCI_OPTION_ROM_RUN_X86EMU),y)
LIBX86EMU_OBJS = $(patsubst %,$(obj)/util/x86emu/x86emu/%,$(X86EMU_OBJ)) \
Modified: coreboot-v3/util/x86emu/vm86.c
===================================================================
--- coreboot-v3/util/x86emu/vm86.c 2008-02-20 13:33:36 UTC (rev 612)
+++ coreboot-v3/util/x86emu/vm86.c 2008-02-21 05:20:14 UTC (rev 613)
@@ -30,77 +30,6 @@
#include <io.h>
-/* Declare a temporary global descriptor table -
- * necessary because the core part of the bios
- * no longer sets up any 16 bit segments
- */
-
-__asm__ (
- /* pointer to original gdt */
- " .globl gdtarg\n"
- "gdtarg: \n"
- " .word gdt_limit \n"
- " .long gdtptr \n"
-
- /* compute the table limit */
- "__mygdt_limit = __mygdt_end - __mygdt - 1 \n"
- " .globl __mygdtaddr\n"
- "__mygdtaddr: \n"
- " .word __mygdt_limit \n"
- " .long __mygdt \n"
-
- " .globl __mygdt\n"
- "__mygdt: \n"
- /* selgdt 0, unused */
- " .word 0x0000, 0x0000 \n"
- " .byte 0x00, 0x00, 0x00, 0x00 \n"
-
- /* selgdt 8, unused */
- " .word 0x0000, 0x0000 \n"
- " .byte 0x00, 0x00, 0x00, 0x00 \n"
-
- /* selgdt 0x10, flat code segment */
- " .word 0xffff, 0x0000 \n"
- " .byte 0x00, 0x9b, 0xcf, 0x00 \n"
-
- /* selgdt 0x18, flat data segment */
- " .word 0xffff, 0x0000 \n"
- " .byte 0x00, 0x93, 0xcf, 0x00 \n"
-
- /* selgdt 0x20, unused */
- " .word 0x0000, 0x0000 \n"
- " .byte 0x00, 0x00, 0x00, 0x00 \n"
-
- /* selgdt 0x28 16-bit 64k code at 0x00000000 */
- " .word 0xffff, 0x0000 \n"
- " .byte 0, 0x9a, 0, 0 \n"
-
- /* selgdt 0x30 16-bit 64k data at 0x00000000 */
- " .word 0xffff, 0x0000 \n"
- " .byte 0, 0x92, 0, 0 \n"
-
- "__mygdt_end: \n"
-
- /* FIXME: This does probably not belong here */
- " .globl idtarg\n"
- "idtarg:\n"
- " .word _idt_end - _idt - 1\n" /* limit */
- " .long _idt\n"
- " .word 0\n"
- "_idt:\n"
- " .fill 20, 8, 0\n" // # idt is unitiailzed
- "_idt_end:\n"
-
- /* Declare a pointer to where our idt is going to be i.e. at mem zero */
- " .globl __myidt\n"
- "__myidt: \n"
- /* 16-bit limit */
- " .word 1023 \n"
- /* 24-bit base */
- " .long 0 \n"
- " .word 0 \n"
-);
-
/* The address arguments to this function are PHYSICAL ADDRESSES */
static void real_mode_switch_call_vga(unsigned long devfn)
{
Added: coreboot-v3/util/x86emu/vm86_gdt.c
===================================================================
--- coreboot-v3/util/x86emu/vm86_gdt.c (rev 0)
+++ coreboot-v3/util/x86emu/vm86_gdt.c 2008-02-21 05:20:14 UTC (rev 613)
@@ -0,0 +1,95 @@
+/*
+ * Erik Arjan Hendriks <hendriks at lanl.gov>
+ * Copyright (C) 2000 Scyld.
+ * Copyright (C) 2000 Scyld Computing Corporation
+ * Copyright (C) 2001 University of California. LA-CC Number 01-67.
+ * Copyright (C) 2005 Nick.Barker9 at btinternet.com
+ * Copyright (C) 2007 coresystems GmbH
+ *
+ * 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.
+ *
+ */
+
+
+/* Declare a temporary global descriptor table -
+ * necessary because the core part of the bios
+ * no longer sets up any 16 bit segments
+ */
+
+__asm__ (
+ /* pointer to original gdt */
+ " .globl gdtarg\n"
+ "gdtarg: \n"
+ " .word gdt_limit \n"
+ " .long gdtptr \n"
+
+ /* compute the table limit */
+ "__mygdt_limit = __mygdt_end - __mygdt - 1 \n"
+ " .globl __mygdtaddr\n"
+ "__mygdtaddr: \n"
+ " .word __mygdt_limit \n"
+ " .long __mygdt \n"
+
+ " .globl __mygdt\n"
+ "__mygdt: \n"
+ /* selgdt 0, unused */
+ " .word 0x0000, 0x0000 \n"
+ " .byte 0x00, 0x00, 0x00, 0x00 \n"
+
+ /* selgdt 8, unused */
+ " .word 0x0000, 0x0000 \n"
+ " .byte 0x00, 0x00, 0x00, 0x00 \n"
+
+ /* selgdt 0x10, flat code segment */
+ " .word 0xffff, 0x0000 \n"
+ " .byte 0x00, 0x9b, 0xcf, 0x00 \n"
+
+ /* selgdt 0x18, flat data segment */
+ " .word 0xffff, 0x0000 \n"
+ " .byte 0x00, 0x93, 0xcf, 0x00 \n"
+
+ /* selgdt 0x20, unused */
+ " .word 0x0000, 0x0000 \n"
+ " .byte 0x00, 0x00, 0x00, 0x00 \n"
+
+ /* selgdt 0x28 16-bit 64k code at 0x00000000 */
+ " .word 0xffff, 0x0000 \n"
+ " .byte 0, 0x9a, 0, 0 \n"
+
+ /* selgdt 0x30 16-bit 64k data at 0x00000000 */
+ " .word 0xffff, 0x0000 \n"
+ " .byte 0, 0x92, 0, 0 \n"
+
+ "__mygdt_end: \n"
+
+ /* FIXME: This does probably not belong here */
+ " .globl idtarg\n"
+ "idtarg:\n"
+ " .word _idt_end - _idt - 1\n" /* limit */
+ " .long _idt\n"
+ " .word 0\n"
+ "_idt:\n"
+ " .fill 20, 8, 0\n" // # idt is unitiailzed
+ "_idt_end:\n"
+
+ /* Declare a pointer to where our idt is going to be i.e. at mem zero */
+ " .globl __myidt\n"
+ "__myidt: \n"
+ /* 16-bit limit */
+ " .word 1023 \n"
+ /* 24-bit base */
+ " .long 0 \n"
+ " .word 0 \n"
+);
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