X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Floader.S;h=dd87ea1c794bc1759ceca654fc953eaea082d763;hb=161bf03beb0aae6ad38aa884cd534a94737d396a;hp=a5819dd28429080f7e6e5f7b70dd277579d12950;hpb=a03618133f7df0954802a470a4bee7674f7aed45;p=pintos-anon

diff --git a/src/threads/loader.S b/src/threads/loader.S
index a5819dd..dd87ea1 100644
--- a/src/threads/loader.S
+++ b/src/threads/loader.S
@@ -29,11 +29,12 @@
 # Configure serial port so we can report progress without connected VGA.
 # See [IntrList] for details.
 	sub %dx, %dx			# Serial port 0.
-	mov $0x00e3, %ax		# 9600 bps, N-8-1.
+	mov $0xe3, %al			# 9600 bps, N-8-1.
+					# AH is already 0 (Initialize Port).
 	int $0x14			# Destroys AX.
 
 	call puts
-	.string "Pintos loader"
+	.string "PiLo"
 
 #### Read the partition table on each system hard disk and scan for a
 #### partition of type 0x20, which is the type that we use for a
@@ -209,8 +210,12 @@ putc:	pusha
 
 	mov $0x01, %ah			# Serial port output service.
 	sub %dx, %dx			# Serial port 0.
-	int $0x14			# Destroys AH.
+2:	int $0x14			# Destroys AH.
+	test $0x80, %ah			# Output timed out?
+	jz 3f
+	movw $0x9090, 2b		# Turn "int $0x14" above into NOPs.
 
+3:
 	cmp $'\r', %al
 	jne popa_ret
 	mov $'\n', %al
@@ -224,8 +229,9 @@ putc:	pusha
 
 read_sector:
 	pusha
-	sub %eax, %eax
-	push %eax			# LBA sector number [32:63]
+	sub %ax, %ax
+	push %ax			# LBA sector number [48:63]
+	push %ax			# LBA sector number [32:47]
 	push %ebx			# LBA sector number [0:31]
 	push %es			# Buffer segment
 	push %ax			# Buffer offset (always 0)