Merge branch 'trini@ti.com' of git://git.denx.de/u-boot-staging

[platform/kernel/u-boot.git] / arch / x86 / lib / realmode_switch.S

diff --git a/arch/x86/lib/realmode_switch.S b/arch/x86/lib/realmode_switch.S
index 7ee709a..c4c4c43 100644 (file)
--- a/arch/x86/lib/realmode_switch.S
+++ b/arch/x86/lib/realmode_switch.S
@@ -44,12 +44,13 @@
  *     e40 ss;
  */
 
-#define a32            .byte 0x67;             /* address size prefix 32 */
-#define o32            .byte 0x66;             /* operand size prefix 32 */
+#define a32            .byte 0x67;     /* address size prefix 32 */
+#define o32            .byte 0x66;     /* operand size prefix 32 */
 
 .section .realmode, "ax"
 .code16
-                                               /* 16bit protected mode code here */
+
+       /* 16bit protected mode code here */
 .globl realmode_enter
 realmode_enter:
 o32    pusha
@@ -69,20 +70,23 @@ o32 pushf
        movw    %ax, %gs
 
        lidt    realmode_idt_ptr
-       movl    %cr0, %eax                      /* Go back into real mode by */
-       andl    $0x7ffffffe, %eax               /* clearing PE to 0 */
+       /* Go back into real mode by clearing PE to 0 */
+       movl    %cr0, %eax
+       andl    $0x7ffffffe, %eax
        movl    %eax, %cr0
-       ljmp    $0x0,$do_realmode               /* switch to real mode */
 
-do_realmode:                                   /* realmode code from here */
+       /* switch to real mode */
+       ljmp    $0x0,$do_realmode
+
+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 */
-
+       /* create a temporary stack */
        movw    $0xc0, %ax
        movw    %ax, %ss
        movw    $0x200, %ax
@@ -114,26 +118,29 @@ o32       popf
        popw    %ss
        movl    %eax, %esp
 cs     movl    temp_eax, %eax
-       wbinvd                                  /* self-modifying code,
-                                                * better flush the cache */
+
+       /* self-modifying code, better flush the cache */
+       wbinvd
 
        .byte   0x9a                            /* lcall */
 temp_ip:
        .word   0                               /* new ip */
 temp_cs:
        .word   0                               /* new cs */
+
 realmode_ret:
-                                               /* save eax, esp and ss */
+       /* save eax, esp and ss */
 cs     movl    %eax, saved_eax
        movl    %esp, %eax
 cs     movl    %eax, saved_esp
        movw    %ss, %ax
 cs     movw    %ax, saved_ss
 
-       /* restore the stack, note that we set sp to 0x244;
+       /*
+        * 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 */
-
+        * backwards on to the stack, bottom first
+        */
        movw    $0xc0, %ax
        movw    %ax, %ss
        movw    $0x244, %ax
@@ -169,12 +176,15 @@ cs        movw    temp_ip, %ax
        pushl   %ebx
 
 o32 cs lidt    saved_idt
-o32 cs lgdt    saved_gdt                       /* Set GDTR */
+o32 cs lgdt    saved_gdt
 
-       movl    %cr0, %eax                      /* Go back into protected mode */
-       orl     $1,%eax /* reset PE to 1 */
+       /* Go back into protected mode reset PE to 1 */
+       movl    %cr0, %eax
+       orl     $1,%eax
        movl    %eax, %cr0
-       jmp     next_line                       /* flush prefetch queue */
+
+       /* flush prefetch queue */
+       jmp     next_line
 next_line:
        movw    $return_ptr, %ax
        movw    %ax,%bp
@@ -182,12 +192,13 @@ o32 cs    ljmp    *(%bp)
 
 .code32
 protected_mode:
-       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 */
+       /* Reload segment registers */
+       movl    $0x18, %eax
+       movw    %ax, %fs
+       movw    %ax, %ds
+       movw    %ax, %gs
+       movw    %ax, %es
+       movw    %ax, %ss
        movl    saved_protected_mode_esp, %eax
        movl    %eax, %esp
        popf