syslinux: fix sector arrays

The first sector ptr is in bs->NextSector not in the array in
the patch_area. And actually the ADV sectors counting is wrong for a
while ...

Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/core/adv.inc b/core/adv.inc
index 2dc1633..6725261 100644 (file)
--- a/core/adv.inc
+++ b/core/adv.inc
@@ -77,8 +77,8 @@ adv_init:
                mov bx,[DataSectors]
                shl bx,2
                mov ecx,[bsHidden]
-               mov eax,[bx+SectorPtrs]         ; First ADV sector
-               mov edx,[bx+SectorPtrs+4]       ; Second ADV sector
+               mov eax,[bx+SectorPtrs-4]; First ADV sector
+               mov edx,[bx+SectorPtrs] ; Second ADV sector
                add eax,ecx
                add edx,ecx
                mov [ADVSec0],eax

diff --git a/extlinux/main.c b/extlinux/main.c
index dea2d19..6bf6872 100644 (file)
--- a/extlinux/main.c
+++ b/extlinux/main.c
@@ -561,7 +561,7 @@ int patch_file_and_bootblock(int fd, const char *dir, int devfd)
     nptrs = get_16(&patcharea->secptrcnt);
 
     memset(wp, 0, nptrs * 4);
-    while (nsect--)
+    while (--nsect) /* the first sector in bs->NextSector */
        set_32(wp++, *sectp++);
 
     /* Poke in the base directory path */

diff --git a/libinstaller/syslxmod.c b/libinstaller/syslxmod.c
index e18d8a6..be06b9a 100644 (file)
--- a/libinstaller/syslxmod.c
+++ b/libinstaller/syslxmod.c
@@ -269,7 +269,7 @@ int syslinux_patch(const uint32_t * sectors, int nsectors,
                       get_16_sl(&patcharea->secptroffset));
     nptrs = get_16_sl(&patcharea->secptrcnt);
 
-    while (nsect--) {
+    while (--nsect) { /* the first sector is in bs->NextSector */
        set_32_sl(wp++, *sectors++);
        nptrs--;
     }