Strip down bootloader and tweak to load multiple blocks

1 files changed, 22 insertions, 53 deletions

diff --git a/bootloader.asm b/bootloader.asm
index 2993726..cf8ccb4 100644
--- a/bootloader.asm
+++ b/bootloader.asm
@@ -10,21 +10,10 @@ start:
   mov si, HELLO
   call write_str
   call disk_read
-  mov si, VERIFY
+  call verify_read
+  mov si, READ_NERR
   call write_str
-  mov ax, 0x61
-  call cursor_next_line
-  call write_char_default_attr
-  mov ax, 0x62
-  call cursor_next_line
-  call write_char_default_attr
-  mov ax, 0x63
-  call cursor_next_line
-  call write_char_default_attr
-  call write_char_default_attr
-  call write_char_default_attr
-  call cursor_back_one
-  call cursor_backspace
+  jmp 0x7e00
   jmp hang
 
 read_err:
@@ -33,6 +22,21 @@ read_err:
 hang:
   jmp hang
 
+verify_read:
+  mov al, 0x66
+  cmp al, [0x7e00]
+  jne read_err
+  mov al, 0x55
+  cmp al, [0x7e01]
+  jne read_err
+  mov al, 0x66
+  cmp al, [0x7e02]
+  jne read_err
+  mov al, 0x89
+  cmp al, [0x7e03]
+  jne read_err
+  ret
+
 write_str:
   push ax
   push si
@@ -86,14 +90,12 @@ disk_read:
   mov ah, 0x42
   int 0x13
   jc read_err
-  mov si, READ_SUCC
-  call write_str
   ret
 
 READ_ERR:
   db 'Read failed: ', 0
-READ_SUCC:
-  db 'Read didnt fail: ', 0
+READ_NERR:
+  db 'No err reading, continuing: ', 0
 HELLO:
   db 'Bootloader init: ', 0
 CURSOR_LOC:
@@ -103,45 +105,12 @@ CURSOR_LOC:
 LBA_DISK_READ_PACKET:
   db 0x10
   db 0
-  dw 1      ; number of blocks to read, reset to # actually read when done
+  dw 32     ; number of blocks to read, reset to # actually read when done
   dw 0x7e00 ; read destination address
-  dw 0
+  dw 0x0000
   dd 1      ; lba to read from
   dd 0      ; for extended lba adresses (not really used here)
 
   times 510-($-$$) db 0
   db 0x55
   db 0xAA
-
-cursor_next_line:
-  mov di, [CURSOR_LOC]
-  add di, 160
-  mov [CURSOR_LOC], di
-  ret
-
-cursor_prev_line:
-  mov di, [CURSOR_LOC]
-  sub di, 160
-  mov [CURSOR_LOC], di
-  ret
-
-cursor_backspace:
-  push ax
-  call cursor_back_one
-  mov ax, 0x00
-  call write_char_default_attr
-  call cursor_back_one
-  pop ax
-  ret
-
-cursor_back_one:
-  mov di, [CURSOR_LOC]
-  dec di
-  dec di
-  mov [CURSOR_LOC], di
-  ret
-
-VERIFY:
-  db '[x] read next block: ', 0
-
-  times 1024-($-$$) db 0