core: move PartInfo back to the top of stack

Move PartInfo back to near the top of the stack.  This makes it less
likely that it ends up getting overwritten during the act of copying
itself.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/core/diskstart.inc b/core/diskstart.inc
index 7bb47dc..bd819a9 100644 (file)
--- a/core/diskstart.inc
+++ b/core/diskstart.inc
@@ -17,21 +17,20 @@
 ; Common early-bootstrap code for harddisk-based Syslinux derivatives.
 ;
 
-               section .earlybss
-               alignb 16
-PartInfo:                              ; Partition table info
-.mbr:          resb 16                 ; MBR partition info
-.gptlen:       resd 1
-.gpt:          resb 56                 ; GPT partition info (minus name)
-FloppyTable    resb 16                 ; Floppy info table (must follow PartInfo)
-
                section .init
 ;
 ; Some of the things that have to be saved very early are saved
 ; "close" to the initial stack pointer offset, in order to
 ; reduce the code size...
 ;
-StackBuf       equ STACK_TOP-44        ; Start the stack here (grow down - 4K)
+
+StackBuf       equ STACK_TOP-44-92     ; Start the stack here (grow down - 4K)
+PartInfo       equ StackBuf
+.mbr           equ PartInfo
+.gptlen                equ PartInfo+16
+.gpt           equ PartInfo+20
+FloppyTable    equ PartInfo+76
+; Total size of PartInfo + FloppyTable == 76+16 = 92 bytes
 Hidden         equ StackBuf-20         ; Partition offset
 OrigFDCTabPtr  equ StackBuf-12         ; The 2nd high dword on the stack
 OrigESDI       equ StackBuf-8          ; The high dword on the stack