working on bootloader (extended mem) (broken!)

1 files changed, 97 insertions, 11 deletions

diff --git a/boot/stage2.asm b/boot/stage2.asm
index ebc346e..3fde5c1 100644
--- a/boot/stage2.asm
+++ b/boot/stage2.asm
@@ -27,10 +27,10 @@
 ;we want 16-bit instructions, before we switch to 32-bit protected mode.
 [bits 16]
 
-;define origin of boot record in memory: 0x7c00
+;define origin of boot record in memory: 0x7c00 was bootloader0
 ;this is where the BIOS per definition will put the first 
 ;512 bytes of data from the boot device
-;The Boot record is identified by the last 2 magic bytes: 0xaa55 (?)
+;wer are one sector after that.
 [org 0x7e00]
 
 ;;define some constants
@@ -49,6 +49,8 @@ jmp boot_16 ;start boot process
 ;;SOME Global Data, mainly info/error strings
 BOOT_DRIVE:
     db 0xff
+KERNEL_CHUNK:
+    dw 0x1
 STR_VERSION:
     db "Fool Loader Stage 2 v0.5",0
 
@@ -58,6 +60,8 @@ STR_BOOT:
     db "Boot Drive: ",0
 MEMMAP_INFO:
     db "Getting Memory Map from BIOS.",0
+STR_PM:
+    db "PROTECTED MODE",0
 
 ;
 ;;lets put our temporary GDT (Global Descriptor Table) here
@@ -72,6 +76,11 @@ MEMMAP_INFO:
 ;
 ;;include our routines for switching to 32-bit protected mode
 %include "boot/pm.asm"
+
+;include some pm mode helpers
+%include "boot/common_pm.asm"
+
+;
 ;
 ;
 ;;get memory map routine
@@ -82,29 +91,27 @@ MEMMAP_INFO:
 ;;lets start
 [bits 16]
 
+idt_real:
+    dw 0x3ff	    ; 256 entries, 4b each = 1K
+	dd 0		; Real Mode IVT @ 0x0000
+
 boot_16:
 
     mov [BOOT_DRIVE],dl
 
-;   pr info 
+    ;pr info 
     mov bx, STR_VERSION
     call print_string
     call print_nextline
 
+    ;show bootdrive
     mov bx, STR_BOOT
     call print_string
     mov al,dl
     call print_hex_byte
     call print_nextline
 
-    ;show bootdrive
 
-    ;   Load the KERNEL Image
-    mov bx, STR_LOAD
-    call print_string
-    call print_nextline
-    call disk_load_16
-   
     ; memmap message
     mov bx,MEMMAP_INFO
     call print_string
@@ -117,7 +124,13 @@ boot_16:
     call BiosGetMemoryMap    ; this will also put the number of entries 
 	                     ; of the memory map at MEMMAP_SIZE_OFFSET
 
-    call VesaSetup
+kernel_load:
+    ;   Load the KERNEL Image
+    mov bx, STR_LOAD
+    call print_string
+    call print_nextline
+    call disk_load_16
+
    
     call switch_to_pm
 ;
@@ -132,8 +145,81 @@ boot_32_pm:
     or al, 2
     out 0x92, al
 
+
+    ; tell the world we are protected
+    mov ebx,STR_PM
+    mov ecx,2*23*80
+    call print_string_pm
+
+    push edx ; persist edx for some reason!?
+
+    mov edx,0
+    mov dx,[KERNEL_CHUNK]
+    mov ecx,2*24*80
+    call print_hex_pm
+
+
+
+    ; here we should move the chunk away or stop the loop if everything loaded.
+    mov ax,[KERNEL_CHUNK]
+    add ax,1
+    mov [KERNEL_CHUNK],ax
+
+	; here we should copy the chunk into ext mem!
+
+
+
+
+    ; and now go back to real! (first 16bit protected!)
+    cmp edx,0x20
+    je finish_load
+    pop edx
+
+
+
+    jmp CODE16_SEG:reinit_16
+    finish_load:
+    ;
+
+    call VesaSetup
+
     ; call kernel!
     mov eax,0		;tell the kernel 
 			; we are the booting processor
     call 0x18000        ;jump into our Kernel!
 
+
+[bits 16]
+reinit_16: ;16 bit protected mode
+
+    mov eax,DATA16_SEG
+    mov ds,eax
+    mov es,eax
+    mov fs,eax
+    mov gs,eax
+    mov ss,eax
+
+
+    mov eax,cr0
+    and eax,!0x1    ; Disable protected mode
+    mov cr0, eax
+
+    jmp 0:realmode
+
+
+realmode:
+
+    mov sp,0x07bff
+    mov bp,sp
+
+    mov ax,0
+    mov ds,ax
+    mov es,ax
+    mov fs,ax
+    mov gs,ax
+    mov ss,ax
+
+    lidt [idt_real]
+
+    sti
+    jmp kernel_load