From: Michael Brown <mcb30@etherboot.org>
Date: Wed, 24 May 2006 12:19:16 +0000 (+0000)
Subject: Set carry flag before calling INT 15,e801 and INT 15,e820.
X-Git-Tag: fredrik-command-line-merge-1~116
X-Git-Url: http://git.etherboot.org/people/xl0/gpxe.git/commitdiff_plain/53935e9dc6c61a002511f31b3fd536ed2a30dc6b

Set carry flag before calling INT 15,e801 and INT 15,e820.

Ignore carry flag for INT 15,88; the Ralf Brown interrupt list says
that CF is unreliable for this call.
---

diff --git a/src/arch/i386/firmware/pcbios/memmap.c b/src/arch/i386/firmware/pcbios/memmap.c
index 3e508fb1..a1e69e02 100644
--- a/src/arch/i386/firmware/pcbios/memmap.c
+++ b/src/arch/i386/firmware/pcbios/memmap.c
@@ -76,6 +76,7 @@ static unsigned int extmemsize_e801 ( void ) {
 	unsigned int extmem;
 
 	REAL_EXEC ( rm_mem_e801,
+		    "stc\n\t"
 		    "int $0x15\n\t"
 		    "pushfw\n\t"
 		    "popw %w0\n\t",
@@ -111,10 +112,8 @@ static unsigned int extmemsize_88 ( void ) {
 	uint16_t extmem;
 
 	REAL_EXEC ( rm_mem_88,
-		    "int $0x15\n\t"
-		    "jnc 1f\n\t"
-		    "xorw %%ax, %%ax\n\t"
-		    "\n1:\n\t",
+		    /* Ignore CF; it is not reliable for this call */
+		    "int $0x15\n\t",
 		    1,
 		    OUT_CONSTRAINTS ( "=a" ( extmem ) ),
 		    IN_CONSTRAINTS ( "a" ( 0x8800 ) ),
@@ -155,6 +154,7 @@ static int meme820 ( struct memory_region *memmap, unsigned int entries ) {
 
 	do {
 		REAL_EXEC ( rm_mem_e820,
+			    "stc\n\t"
 			    "int $0x15\n\t"
 			    "pushfw\n\t"
 			    "popw %w0\n\t",