/*
- * U-boot - i386 Startup Code
+ * U-boot - i386 Startup Code
*
- * Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
+ * Copyright (c) 2002, 2003 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
*
* See file CREDITS for list of people who contributed to this
* project.
.section .start16, "ax"
.code16
.globl start16
-start16:
+start16:
/* First we let the BSP do some early initialization
* this code have to map the flash to its final position
*/
mov $board_init16_ret, %bp
jmp board_init16
-board_init16_ret:
-
+board_init16_ret:
+
/* Turn of cache (this might require a 486-class CPU) */
- movl %cr0, %eax
- orl $060000000,%eax
- movl %eax, %cr0
- wbinvd
-
+ movl %cr0, %eax
+ orl $0x60000000,%eax
+ movl %eax, %cr0
+ wbinvd
+
/* load the descriptor tables */
o32 cs lidt idt_ptr
-o32 cs lgdt gdt_ptr
+o32 cs lgdt gdt_ptr
/* Now, we enter protected mode */
- movl %cr0, %eax
- orl $1,%eax
- movl %eax, %cr0
-
+ movl %cr0, %eax
+ orl $1,%eax
+ movl %eax, %cr0
+
/* Flush the prefetch queue */
- jmp ff
+ jmp ff
ff:
/* Finally jump to the 32bit initialization code */
- movw $code32start, %ax
- movw %ax,%bp
+ movw $code32start, %ax
+ movw %ax,%bp
o32 cs ljmp *(%bp)
/* 48-bit far pointer */
idt_ptr:
.word 0 /* limit */
.long 0 /* base */
-
+
gdt_ptr:
.word 0x30 /* limit (48 bytes = 6 GDT entries) */
.long BOOT_SEG + gdt /* base */
- /* The GDT table ...
+ /* The GDT table ...
*
- * Selector Type
+ * Selector Type
* 0x00 NULL
* 0x08 Unused
- * 0x10 32bit code
+ * 0x10 32bit code
* 0x18 32bit data/stack
* 0x20 16bit code
* 0x28 16bit data/stack
.word 0x0 /* base address = 0 */
.word 0x9300 /* data read/write */
.word 0x00CF /* granularity = 4096, 386 (+5th nibble of limit) */
-
+
.word 0xFFFF /* 64kb */
.word 0 /* base address = 0 */
.word 0x9b00 /* data read/write */
.word 0x0010 /* granularity = 1 (+5th nibble of limit) */
-
+
.word 0xFFFF /* 64kb */
.word 0 /* base address = 0 */
.word 0x9300 /* data read/write */