gptmbr: shuffle slightly to reduce register pressure

Shuffle some code slightly to reduce register pressure; no size change
but this might make the code easier to follow and/or change.

diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S
index 138ac51..80b26ed 100644 (file)
--- a/mbr/gptmbr.S
+++ b/mbr/gptmbr.S
@@ -178,8 +178,6 @@ found_part:
        stosl
        movl    40(%si),%eax
        movl    48(%si),%edx
-       pushl   %eax
-       pushl   %edx
        call    saturate_stosl          /* Partition start */
 
        subl    32(%si),%eax
@@ -188,16 +186,15 @@ found_part:
        call    saturate_stosl          /* Partition length */
 
        rep; movsb                      /* GPT entry follows MBR entry */
-       popl    %edx
-       popl    %eax
        popw    %si
 
 /*
  * boot: invoke the actual bootstrap. %ds:%si points to the
- * partition information in memory, and %edx:%eax to the boot sector
- * on disk.
+ * partition information in memory.
  */
 boot:
+       movl    (40+16)(%si),%eax
+       movl    (48+16)(%si),%edx
        call    read_sector
        cmpw    $0xaa55, (bootsec+510)
        jne     missing_os      /* Not a valid boot sector */