From 93a9c3d5e9ba566585fa4c082696422454491d78 Mon Sep 17 00:00:00 2001
From: Ain <41307858+nero@users.noreply.github.com>
Date: Thu, 19 Sep 2019 20:12:35 +0000
Subject: [PATCH] Make drive table data offsets available via defines

---
 kernel/drive.asm | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/kernel/drive.asm b/kernel/drive.asm
index 9f0b714..243b8e0 100644
--- a/kernel/drive.asm
+++ b/kernel/drive.asm
@@ -1,24 +1,23 @@
-%define drive_struct_len 0x0C
+; drive table
+%define drivetab_type    0x00 ; BYTE 0=unassigned, 1=BIOS/CHS, 2=BIOS/LBA
+%define drivetab_num     0x01 ; BYTE DL number
+%define drivetab_heads   0x02 ; CHS heads
+%define drivetab_spt     0x03 ; CHS sectors per track
+%define drivetab_sectors 0x04 ; total number of sectors
+%define drivetab_offset  0x08 ; partition offset
+%define drivetab_size    0x0C
 
 drive_table:
   dw 0
 .count:
   dw 4
 
-; Drive table
-; 00  BYTE     DL number
-; 01  BYTE     file system type
-; 02  BYTE     CHS heads (ignored if LBA)
-; 03  BYTE     CHS sectors per track (ignored if LBA)
-; 04  DWORD    total number of sectors
-; 08  DWORD    partition offset
-
 ; DI is incremented for the space taken
 ; IN	ES:DI
 drive_setup:
   xor cx, cx
   mov [drive_table], di
-  mov al, drive_struct_len
+  mov al, drivetab_size
   mov ah, BYTE [drive_table.count]
   mul ah
   xchg cx, ax
@@ -39,7 +38,7 @@ drive_load:
   mov si, [drive_table]
 
   push ax
-  mov al, drive_struct_len
+  mov al, drivetab_size
   mul dl
   add si, ax
   pop ax