Ugly workaround for bug in GNU ld 2.17

GNU ld 2.17, which is still included with Debian 4.0 (etch),
mishandles PC-relative relocations to an absolute address.  Hack
around it by making pm_entry a segment-relative symbol, completely
unnecessarily so.

diff --git a/core/com32.inc b/core/com32.inc
index 9995420..bd6d727 100644 (file)
--- a/core/com32.inc
+++ b/core/com32.inc
@@ -26,8 +26,17 @@
 ; "mov ax,0x4cff; int 0x21" in 16-bit mode.  This will abort the
 ; program with an error if run in 16-bit mode.
 ;
-pm_idt:                equ 0x100000
-pm_entry:      equ 0x101000
+
+               ; We need to make this a proper section rather
+               ; than using absolute numbers, in order to work
+               ; around a bug in GNU ld 2.17, which is still in
+               ; use as of this writing in the form of Debian
+               ; 4.0 (etch).
+               bits 32
+               section .com32 exec write nobits align=16
+pm_idt         equ 0x100000            ; Needs to be absolute...
+               resb 4096
+pm_entry:                              ; Needs to not be...
 
                bits 16
                section .data

diff --git a/core/syslinux.ld b/core/syslinux.ld
index 28ef44e..f59e5b1 100644 (file)
--- a/core/syslinux.ld
+++ b/core/syslinux.ld
@@ -118,4 +118,9 @@ SECTIONS
        __bss1_dwords = (__bss1_len + 3) >> 2;
 
        . = ASSERT(__bss1_end <= 0x10000, "64K overflow");
+
+       . = 0x100000;
+       .com32 : {
+               *(.com32)
+       }
 }