From 44fa7a529656c1ec8a445cac4ee7b40351a7c753 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Tue, 28 Jul 2020 22:00:26 +0200
Subject: Make the bin smaller so direct pointers are enough

This is not a final sollution but will work for the moment. I'm just too
confused by assembly so I implemented some tricks to shrink the binary.
---
 src/entry.asm | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

(limited to 'src/entry.asm')

diff --git a/src/entry.asm b/src/entry.asm
index 4b8b247..5fdf4c2 100644
--- a/src/entry.asm
+++ b/src/entry.asm
@@ -311,8 +311,9 @@ kernel_load:
 	xor ax, ax ; Clear ax
 	mov dx, ax ; Clear dx
 
-	cmp cx, EXT2_DIRECT_POINTER_COUNT ; Indirect pointer needed?
-	jge .indirect ; Singly indirect pointer
+	; TODO: Add singly pointer support (until ~12KiB)
+	;cmp cx, EXT2_DIRECT_POINTER_COUNT ; Indirect pointer needed?
+	;jge .indirect ; Singly indirect pointer
 
 	mov ax, [di] ; Set ax = block pointer
 	shl ax, 1 ; Multiply ax by 2
@@ -328,22 +329,23 @@ kernel_load:
 
 	xor ebx, ebx
 
+	; Read singly indirect pointer
 	mov bx, EXT2_GET_ADDRESS(EXT2_KERNEL_INODE) ; First block
 	lea di, [bx + EXT2_IND_POINTER_OFFSET] ; Address of singly indirect pointer
 	mov bx, 0x3000 ; Arbitrary address
-
 	mov ax, [di] ; Set ax = block pointer
 	shl ax, 1 ; Multiply ax by 2
 	mov [lba], ax
 	mov [dest], bx
 	call disk_read
 
+	; Read data
 	sub cx, EXT2_DIRECT_POINTER_COUNT
 	lea di, [ebx + 4 * ecx]
 	mov bx, 0x4000 ; Arbitrary address
-
 	mov ax, [di]
 	shl ax, 1
+	;sub bx, 0x400
 	mov [lba], ax
 	mov [dest], bx
 	call disk_read
-- 
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