From 6a4ffe2abb885b7d39346d0ec3aa8346f3b5bfd3 Mon Sep 17 00:00:00 2001
From: hpa <hpa>
Date: Wed, 28 Mar 2001 05:11:21 +0000
Subject: [PATCH] Add hack that hopefully will make -s mode less necessary

---
 NEWS        |  3 +++
 ldlinux.asm | 18 +++++++++---------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/NEWS b/NEWS
index a0ad693..d57e63d 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,9 @@ Changes in 1.54:
 	* PXELINUX: Fix code for finding !PXE from PXENV+.  This was
 	  due to a spec bug; match the most recent spec since that
 	  seems to be what implementations actually do.
+	* SYSLINUX: Add some smarts to the boot sector, which
+	  hopefully should reduce the number of systems which require 
+	  stupid mode ("syslinux -s").
 
 Changes in 1.53:
 	* PXELINUX: Rename pxelinux.bin to pxelinux.0, to match what
diff --git a/ldlinux.asm b/ldlinux.asm
index 9617e25..39301e7 100644
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -588,10 +588,11 @@ wstr_1:         lodsb
 ;
 disk_error:	dec si			; SI holds the disk retry counter
 		jz kaboom
-		xchg ax,bx		; Shorter than MOV
 		pop bx			; <I>
 		pop cx			; <H>
 		pop dx			; <G>
+		pop ax			; <F> (AH = 0)
+		mov al,1		; Once we fail, only transfer 1 sector
 		jmp short disk_try_again
 
 return:		ret
@@ -670,20 +671,19 @@ gls_lastchunk:
 		mov dl,[bsDriveNumber]
 		xchg ax,bp		; Sector to transfer count
 					; (xchg shorter than mov)
-		push ax			; <F> Number of sectors we're transferring
-		mov ah,02h		; Read it!
+		mov si,retry_count	; # of times to retry a disk access
 ;
 ; Do the disk transfer... save the registers in case we fail :(
 ;
-		mov si,retry_count	; # of times to retry a disk access
-disk_try_again: push dx			; <G>
+disk_try_again: 
+		push ax			; <F> Number of sectors we're transferring
+		mov ah,02h		; READ DISK
+		push dx			; <G>
 		push cx			; <H>
 		push bx			; <I>
-		push ax			; <J>
-		push si			; <K>
+		push si			; <J>
 		int 13h
-		pop si			; <K>
-		pop bx			; <J>
+		pop si			; <J>
 		jc disk_error
 ;
 ; Disk access successful
-- 
2.7.4