Changeset 5eb1379 in mainline

Timestamp:

2005-09-04T00:05:47Z (19 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

005384ad

Parents:

dd80fc6

Message:

basic GRUB memory map

Location:

arch/ia32

Files:

• include/boot/boot.h (modified) (1 diff)
• src/boot/boot.S (modified) (1 diff)

arch/ia32/include/boot/boot.h

@@ -30 +30 @@
 #define __ia32_BOOT_H__
 
-#define BOOTSTRAP_OFFSET                        0x8000
+#define BOOTSTRAP_OFFSET                0x8000
 #define BOOT_OFFSET                             0x100000
 
-#define MULTIBOOT_HEADER_MAGIC          0x1BADB002
-#define MULTIBOOT_HEADER_FLAGS          0x00010003
+#define MULTIBOOT_HEADER_MAGIC  0x1BADB002
+#define MULTIBOOT_HEADER_FLAGS  0x00010003
+
+#define MULTIBOOT_LOADER_MAGIC  0x2BADB002
 
 #endif

arch/ia32/src/boot/boot.S

@@ -104 +104 @@
         lgdt protected_bootstrap_gdtr - 0x80000000              # initialize Global Descriptor Table register
 
-        movw $KDATA, %ax
-        movw %ax, %es
-        movw %ax, %gs
-        movw %ax, %fs
-        movw %ax, %ds                                                                   # kernel data + stack
-        movw %ax, %ss
+        movw $KDATA, %cx
+        movw %cx, %es
+        movw %cx, %gs
+        movw %cx, %fs
+        movw %cx, %ds                                                                   # kernel data + stack
+        movw %cx, %ss
         
         jmpl $KTEXT, $multiboot_meeting_point + BOOT_OFFSET
         multiboot_meeting_point:
         
+        pushl %ebx
+        pushl %eax
+        
         call map_kernel                                                                 # map kernel and turn paging on
+        
+        popl %eax
+        popl %ebx
+        cmpl $MULTIBOOT_LOADER_MAGIC, %eax
+        je valid_boot
+        
+                # ...
+                
+                jmp invalid_boot
+        
+        valid_boot:
+                
+                movl (%ebx), %eax
+                
+                # ... check flags in eax
+                
+                movl 4(%ebx), %ecx
+                addl 8(%ebx), %ecx
+                movl %ecx, e801memorysize
+                
+#               movl 44(%ebx), %ecx
+                xorl %ecx, %ecx
+                movl %ecx, e820counter
+#               movl 48(%ebx), %esi
+#               movl $e820table, %edi
+#               cld
+#               rep movsb
+                
+        invalid_boot:
         
         call main_bsp - BOOT_OFFSET                                             # never returns