Finally we have a 2 stage bootloader !

This one can load the ramdis up to 0xfffff  :)

2 files changed, 132 insertions, 0 deletions

diff --git a/boot0/disk_load_16.asm b/boot0/disk_load_16.asm
new file mode 100644
index 0000000..55ad4aa
--- /dev/null
+++ b/boot0/disk_load_16.asm
@@ -0,0 +1,78 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;; Miguel's FoolOS Helper Functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+;disk_load_16
+;
+
+
+[bits 16]
+
+STR_LBA:
+    db "\nLBA Support Detected (no support yet)",0
+    
+STR_CHS
+    db "CHS Support Detected",0
+
+STR_ERROR
+    db "Disk Read Error",0
+
+STR_DONE
+    db "Stage 2 Loaded",0
+
+disk_load_16:
+
+    pusha
+    
+   ; check if LBA is supported
+    mov    ah,0x41
+    mov    bx,0x55aa
+    int    0x13                                                    
+    jnc disk_load_lba
+    jmp disk_load_chs
+
+
+disk_load_lba:
+
+    mov bx, STR_LBA
+    call print_string
+    call print_nextline
+    jmp $
+    jmp disk_load_finish
+
+disk_load_chs:
+
+    mov bx, STR_CHS
+    call print_string
+    call print_nextline
+
+    mov bx,0		;target es:bx
+    mov es,bx
+    mov bx,0x7e00
+
+    mov al,50		;number of sectors to read
+    mov ah,0x02		;BIOS read sector func
+
+    mov cl,2 ; sector
+    mov ch,0 ; cylinder
+
+    mov dl,[BOOT_DRIVE]
+    mov dh,0 ;head
+
+    int 0x13		;bios interrupt
+
+    jnc disk_load_finish  
+
+    jmp $
+
+disk_load_finish:
+
+    call print_nextline
+    mov bx, STR_DONE
+    call print_string
+    call print_nextline
+
+
+    popa
+    ret
+   
diff --git a/boot0/mbr.asm b/boot0/mbr.asm
new file mode 100644
index 0000000..d24bbfe
--- /dev/null
+++ b/boot0/mbr.asm
@@ -0,0 +1,54 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+; stage 1
+;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+[bits 16]
+
+[org 0x7c00]
+
+jmp stage1
+
+STR_1:
+    db "Starting Fool Loader Stage 1. v0.1",0
+
+STR_2:
+    db "Starting Stage 2",0
+
+BOOT_DRIVE:
+    db 0xff ; remember the bootdrive here
+
+%include "boot/print_string_16.asm"
+%include "boot0/disk_load_16.asm"
+
+stage1:
+
+    ;first of allsetup the stack (Right under mbr)
+    ;guaranteed ~30KB space
+    mov bp,0x07bff
+    mov sp,bp
+    
+    ;remember BOOT_DRIVE (as was set by BIOS)
+    mov [BOOT_DRIVE],dl	
+
+    mov bx, STR_1
+    call print_string
+    call print_nextline
+
+    call disk_load_16	; loads stage 2
+
+    mov bx, STR_2
+    call print_string
+    call print_nextline
+    jmp 0x7e00 ; jump to next sector where we put stage 2
+
+;fill partition table (4x16byte) with zeroes. 
+;(otherwise my Acer Aspire will not boot)
+times 64 db 0x0
+
+;so we get identified as MBR
+times 510-($-$$) db 0x0
+;dw 0x0
+dw 0xaa55
+