1 files changed, 110 insertions, 0 deletions
diff --git a/purgatory/arch/i386/entry32.S b/purgatory/arch/i386/entry32.S
new file mode 100644
index 0000000..f7a494f
--- /dev/null
+++ b/purgatory/arch/i386/entry32.S
@@ -0,0 +1,110 @@
+/*
+ * purgatory:  setup code
+ *
+ * Copyright (C) 2003,2004  Eric Biederman (ebiederm@xmission.com)
+ *
+ * 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 (version 2 of the License).
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#undef i386
+
+	.text
+	.arch	i386
+	.globl entry32, entry32_regs
+entry32:
+	.code32
+
+	/* Setup a gdt that should that is generally usefully */
+	lgdt	%cs:gdt
+
+	/* load the data segments */
+	movl	$0x18, %eax	/* data segment */
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %ss
+	movl	%eax, %fs
+	movl	%eax, %gs
+
+	/* load the code segment */
+	ljmp	$0x10,$1f
+1:		
+
+	/* Load the registers */
+	movl	eax, %eax
+	movl	ecx, %ecx
+	movl	edx, %edx
+	movl	esi, %esi
+	movl	edi, %edi
+	movl	esp, %esp
+	movl	ebp, %ebp
+	movl	ebx, %ebx
+
+	/* Jump to the loaded image */
+	jmpl	*(eip)
+
+	.section ".rodata"
+	.balign 16
+gdt:
+	/* 0x00 unusable segment so used as the gdt ptr */
+	.word	gdt_end - gdt - 1
+	.long	gdt
+	.word	0
+
+	/* 0x08 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+
+	/* Documented linux kernel segments */
+	/* 0x10 4GB flat code segment */
+	.word	0xFFFF, 0x0000, 0x9A00, 0x00CF
+	/* 0x18 4GB flat data segment */
+	.word	0xFFFF, 0x0000, 0x9200, 0x00CF
+
+	/* 0x20 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x28 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x30 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x38 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x40 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x48 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x50 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	/* 0x58 dummy */
+	.word	0x0000, 0x0000, 0x0000, 0x000
+	
+	/* Segments used by the 2.5.x kernel */
+	/* 0x60 4GB flat code segment */
+	.word	0xFFFF, 0x0000, 0x9A00, 0x00CF
+	/* 0x68 4GB flat data segment */
+	.word	0xFFFF, 0x0000, 0x9200, 0x00CF
+gdt_end:
+	
+	.data 
+	.balign 4
+entry32_regs:  
+eax:	.long 0x00000000
+ebx:	.long 0x00000000
+ecx:	.long 0x00000000
+edx:	.long 0x00000000
+esi:	.long 0x00000000
+edi:	.long 0x00000000
+esp:	.long 0x00000000
+ebp:	.long 0x00000000
+eip:	.long entry16
+	.size entry32_regs, . - entry32_regs
+