Changeset 5dce48b9 in mainline for arch/ia32/src/boot

Timestamp:

2005-09-01T16:40:30Z (21 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

399ccd9

Parents:

2793442

Message:

load the kernel above 1 MB on IA-32

File:

• arch/ia32/src/boot/boot.S (modified) (4 diffs)

arch/ia32/src/boot/boot.S

@@ -43 +43 @@
 kernel_image_start:
         cli
-        xorw %ax,%ax
-        movw %ax,%ds
-        movw %ax,%ss                    # initialize stack segment register
-        movl $0x7c00,%esp               # initialize stack pointer
+        xorw %ax, %ax
+        movw %ax, %ds
+        movw %ax, %ss                   # initialize stack segment register
+        movl $0x7c00, %esp              # initialize stack pointer
         
         call memmap_arch_init
@@ -52 +52 @@
         lgdt gdtr                       # initialize Global Descriptor Table register
         
-        movl %cr0,%eax
-        orl $0x1,%eax
-        movl %eax,%cr0                  # switch to protected mode
-        jmpl $8,$meeting_point
-
+        movl %cr0, %eax
+        orl $0x1, %eax
+        movl %eax, %cr0                 # switch to protected mode
+        
+        jmpl $8, $boot_image_start
+        
 .code32
 .align 4
@@ -63 +64 @@
         .long MULTIBOOT_HEADER_FLAGS
         .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)        # checksum
-        .long multiboot_header
-        .long unmapped_ktext_start
+        .long multiboot_header + BOOT_OFFSET
+        .long unmapped_ktext_start + BOOT_OFFSET
         .long 0
         .long 0
-        .long multiboot_image_start
+        .long multiboot_image_start + BOOT_OFFSET
+        
+boot_image_start:
+        movw $16, %ax
+        movw %ax, %es
+        movw %ax, %gs
+        movw %ax, %fs
+        movw %ax, %ds                   # kernel data + stack
+        movw %ax, %ss
+        
+        call map_kernel                 # map kernel and turn paging on
+        
+        movb $0xd1, %al                 # enable A20 using the keyboard controller
+        outb %al, $0x64
+        movb $0xdf, %al
+        outb %al, $0x60
+        
+        movl $0x8000, %esi
+        movl $0x8000 + BOOT_OFFSET, %edi
+        movl $_hardcoded_kernel_size, %ecx
+        cld
+        rep movsb
+        
+        jmp protected
         
 multiboot_image_start:
@@ -74 +98 @@
         lgdt gdtr
 
-meeting_point:
-        movw $16,%ax
-        movw %ax,%es
-        movw %ax,%gs
-        movw %ax,%fs
-        movw %ax,%ds                    # kernel data + stack
-        movw %ax,%ss
-
+        movw $16, %ax
+        movw %ax, %es
+        movw %ax, %gs
+        movw %ax, %fs
+        movw %ax, %ds                   # kernel data + stack
+        movw %ax, %ss
+        
         call map_kernel                 # map kernel and turn paging on
-
+        
+protected:
         call main_bsp                   # never returns