Changeset c245372b in mainline for arch/amd64/src/boot/boot.S

Timestamp:

2005-08-29T13:56:47Z (20 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

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

Children:

4dd0704

Parents:

b52da8d7

Message:

Fixed linker script to include .eh_frame section.
It now boots into protected mode.

File:

• arch/amd64/src/boot/boot.S (modified) (1 diff)

arch/amd64/src/boot/boot.S

@@ -40 +40 @@
 #
 kernel_image_start:
+        cli
+        xorw %ax,%ax
+        movw %ax,%ds
+        movw %ax,%ss            # initialize stack segment register
+        movl $0x7c00,%esp       # initialize stack pointer
+        
+        call memmap_arch_init
+        
+        mov $0x80000000, %eax  
+        cpuid
+        cmp $0x80000000, %eax   # any function > 80000000h?
+        jbe no_long_mode
+        mov $0x80000001, %eax   # Extended function code 80000001
+        cpuid
+        bt $29, %edx            # Test if long mode is supported.
+        jnc no_long_mode
 
-meeting_point:
-.code32
+# Fill out GDTR.base, IDTR.base
+        leal gdtr, %eax
+        movl gdt_addr, %ebx
+        movl %ebx, 2(%eax)
 
+        movl idt_addr, %ebx
+        leal idtr, %eax
+        movl %ebx, 2(%eax)
 
-.section K_DATA_START
+# Load gdtr, idtr       
+        lgdt gdtr
+        lidt idtr
+        
+        mov $1, %eax    # Enable protected mode (CR0.PE = 1)
+        mov %eax, %cr0 
 
+        jmpl $8, $now_in_prot
+        
+now_in_prot:
+        
+
+no_long_mode:
+1:
+        jmp 1b
+                        
+
+.section K_DATA_START   
 .align 4096
 page_directory:
         .space 4096, 0
+
+gdt_addr:       
+        .quad gdt + 0x80000000
+idt_addr:       
+        .quad idt + 0x80000000