X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=bootcensus;a=blobdiff_plain;f=src%2Fboot%2Fboot2.s;h=5aeebaa66a0e54dd2c043bbec8620a808d5c8c32;hp=7067a8f308c3f4520f494962fe2ca4ca1e83ddbc;hb=6ddbba6fc0185f6aaf64c661c303549eb088010f;hpb=28d44c4b65b11f37ffd69a2b0227f14ca5c4f137

diff --git a/src/boot/boot2.s b/src/boot/boot2.s
index 7067a8f..5aeebaa 100644
--- a/src/boot/boot2.s
+++ b/src/boot/boot2.s
@@ -230,7 +230,7 @@ ldloop:
 	# just in case we were loaded from floppy, turn all floppy motors off
 	mov $0x3f2, %dx
 	in %dx, %al
-	and $0xf0, %al
+	and $0xf, %al
 	out %al, %dx
 
 	mov $10, %ax
@@ -766,6 +766,7 @@ saved_ebp: .long 0
 saved_eax: .long 0
 saved_es: .word 0
 saved_ds: .word 0
+saved_flags: .word 0
 
 	# drop back to unreal mode to call 16bit interrupt
 	.global int86
@@ -778,7 +779,7 @@ int86:
 	sidt (saved_idtr)
 	lidt (rmidt)
 
-	# modify the int instruction do this here before the
+	# modify the int instruction. do this here before the
 	# cs-load jumps, to let them flush the instruction cache
 	mov $int_op, %ebx
 	movb 8(%ebp), %al
@@ -802,6 +803,7 @@ int86:
 	nop
 
 	# load registers from the int86regs struct
+	# point esp to the regs struct to load registers with popa/popf
 	mov %esp, saved_esp
 	mov %ebp, saved_ebp
 	mov 12(%ebp), %esp
@@ -818,12 +820,17 @@ int86:
 
 	# call 16bit interrupt
 int_op:	int $0
+	# BIOS call might have enabled interrupts, cli for good measure
+	cli
 
 	# save all registers that we'll clobber before having the
 	# chance to populate the int86regs structure
 	mov %eax, saved_eax
 	mov %ds, saved_ds
 	mov %es, saved_es
+	pushfw
+	pop %ax
+	mov %ax, saved_flags
 
 	# re-enable protection
 	mov %cr0, %eax
@@ -840,6 +847,7 @@ int_op:	int $0
 	mov %ax, %ss
 	nop
 
+	# point the esp to our regs struct, to fill it with pusha/pushf
 	mov saved_ebp, %ebp
 	mov 12(%ebp), %esp
 	add $38, %esp
@@ -847,7 +855,8 @@ int_op:	int $0
 	pushw %ax
 	mov saved_es, %ax
 	pushw %ax
-	pushfw
+	mov saved_flags, %ax
+	pushw %ax
 	mov saved_eax, %eax
 	pushal
 	mov saved_esp, %esp