summaryrefslogtreecommitdiff
path: root/lib_i386/realmode_switch.S
diff options
context:
space:
mode:
authorwdenk <wdenk>2003-06-27 21:31:46 +0000
committerwdenk <wdenk>2003-06-27 21:31:46 +0000
commit8bde7f776c77b343aca29b8c7b58464d915ac245 (patch)
tree20f1fd99975215e7c658454a15cdb4ed4694e2d4 /lib_i386/realmode_switch.S
parent993cad9364c6b87ae429d1ed1130d8153f6f027e (diff)
* Code cleanup:LABEL_2003_06_27_2340
- remove trailing white space, trailing empty lines, C++ comments, etc. - split cmd_boot.c (separate cmd_bdinfo.c and cmd_load.c) * Patches by Kenneth Johansson, 25 Jun 2003: - major rework of command structure (work done mostly by Michal Cendrowski and Joakim Kristiansen)
Diffstat (limited to 'lib_i386/realmode_switch.S')
-rw-r--r--lib_i386/realmode_switch.S100
1 files changed, 50 insertions, 50 deletions
diff --git a/lib_i386/realmode_switch.S b/lib_i386/realmode_switch.S
index 17adcbd7fd1..0433cd47c76 100644
--- a/lib_i386/realmode_switch.S
+++ b/lib_i386/realmode_switch.S
@@ -1,7 +1,7 @@
/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se
- *
+ *
* See file CREDITS for list of people who contributed to this
* project.
*
@@ -31,11 +31,11 @@
* e08 edx;
* e0c esi;
* e10 edi;
- * e14 ebp;
+ * e14 ebp;
* e18 eax;
- * e1c ds;
+ * e1c ds;
* e20 es;
- * e24 fs;
+ * e24 fs;
* e28 gs;
* e2c orig_eax;
* e30 eip;
@@ -46,7 +46,7 @@
*/
#define a32 .byte 0x67; /* address size prefix 32 */
-#define o32 .byte 0x66; /* operand size prefix 32 */
+#define o32 .byte 0x66; /* operand size prefix 32 */
.section .realmode, "ax"
.code16
@@ -56,11 +56,11 @@ realmode_enter:
o32 pusha
o32 pushf
cli
- sidt saved_idt
- sgdt saved_gdt
- movl %esp, %eax
- movl %eax, saved_protected_mode_esp
-
+ sidt saved_idt
+ sgdt saved_gdt
+ movl %esp, %eax
+ movl %eax, saved_protected_mode_esp
+
movl $0x10, %eax
movl %eax, %esp
movw $0x28, %ax
@@ -74,21 +74,21 @@ o32 pushf
andl $0x7ffffffe, %eax /* clearing PE to 0 */
movl %eax, %cr0
ljmp $0x0,$do_realmode /* switch to real mode */
-
-do_realmode: /* realmode code from here */
+
+do_realmode: /* realmode code from here */
movw %cs,%ax
movw %ax,%ds
movw %ax,%es
movw %ax,%fs
movw %ax,%gs
-
+
/* create a temporary stack */
-
- movw $0xc0, %ax
- movw %ax, %ss
- movw $0x200, %ax
- movw %ax, %sp
-
+
+ movw $0xc0, %ax
+ movw %ax, %ss
+ movw $0x200, %ax
+ movw %ax, %sp
+
popl %ebx
popl %ecx
popl %edx
@@ -117,11 +117,11 @@ o32 popf
cs movl temp_eax, %eax
wbinvd /* self-modifying code,
* better flush the cache */
-
+
.byte 0x9a /* lcall */
temp_ip:
.word 0 /* new ip */
-temp_cs:
+temp_cs:
.word 0 /* new cs */
realmode_ret:
/* save eax, esp and ss */
@@ -130,16 +130,16 @@ cs movl %eax, saved_eax
cs movl %eax, saved_esp
movw %ss, %ax
cs movw %ax, saved_ss
-
+
/* restore the stack, note that we set sp to 0x244;
* pt_regs is 0x44 bytes long and we push the structure
* backwards on to the stack, bottom first */
-
- movw $0xc0, %ax
- movw %ax, %ss
- movw $0x244, %ax
- movw %ax, %sp
-
+
+ movw $0xc0, %ax
+ movw %ax, %ss
+ movw $0x244, %ax
+ movw %ax, %sp
+
xorl %eax,%eax
cs movw saved_ss, %ax
pushl %eax
@@ -172,28 +172,28 @@ cs movw temp_ip, %ax
o32 cs lidt saved_idt
o32 cs lgdt saved_gdt /* Set GDTR */
- movl %cr0, %eax /* Go back into protected mode */
- orl $1,%eax /* reset PE to 1 */
- movl %eax, %cr0
- jmp next_line /* flush prefetch queue */
-next_line:
- movw $return_ptr, %ax
- movw %ax,%bp
+ movl %cr0, %eax /* Go back into protected mode */
+ orl $1,%eax /* reset PE to 1 */
+ movl %eax, %cr0
+ jmp next_line /* flush prefetch queue */
+next_line:
+ movw $return_ptr, %ax
+ movw %ax,%bp
o32 cs ljmp *(%bp)
.code32
protected_mode:
- movl $0x18,%eax /* reload GDT[3] */
- movw %ax,%fs /* reset FS */
+ movl $0x18,%eax /* reload GDT[3] */
+ movw %ax,%fs /* reset FS */
movw %ax,%ds /* reset DS */
- movw %ax,%gs /* reset GS */
- movw %ax,%es /* reset ES */
- movw %ax,%ss /* reset SS */
- movl saved_protected_mode_esp, %eax
+ movw %ax,%gs /* reset GS */
+ movw %ax,%es /* reset ES */
+ movw %ax,%ss /* reset SS */
+ movl saved_protected_mode_esp, %eax
movl %eax, %esp
popf
popa
- ret
+ ret
temp_eax:
.long 0
@@ -204,19 +204,19 @@ saved_esp:
.long 0
saved_eax:
.long 0
-
+
realmode_idt_ptr:
- .word 0x400
- .word 0x0, 0x0
-
-saved_gdt:
- .word 0, 0, 0, 0
+ .word 0x400
+ .word 0x0, 0x0
+
+saved_gdt:
+ .word 0, 0, 0, 0
saved_idt:
- .word 0, 0, 0, 0
+ .word 0, 0, 0, 0
saved_protected_mode_esp:
.long 0
-
+
return_ptr:
.long protected_mode
.word 0x10