[build] Fix building on mildly deranged versions of binutils

Some versions of binutils have curious concepts of what constitutes
subtraction.  For example:

  0x00000000000000f0 _text16_late = .
  0x0000000000000898 _mtext16 = .
  0x0000000000000898 _etext16 = .
  0x0000000000000898 _text16_late_filesz = ABSOLUTE ((_mtext16 - _text16_late))
  0x00000000000007a8 _text16_late_memsz = ABSOLUTE ((_etext16 - _text16_late))

This has interesting side-effects such as producing sizes for .bss
segments that are negative, causing the majority of addressable memory
to be zeroed out.

Fix by using the form

  ABSOLUTE ( x ) - ABSOLUTE ( y )

rather than

  ABSOLUTE ( x - y )

Reported-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds
index c5bc631fa92473063d2191ad2e825c07620f8e54..763b80d6514d65de3db8801d530ca76b8ba20aba 100644 (file)
--- a/src/arch/i386/scripts/i386.lds
+++ b/src/arch/i386/scripts/i386.lds
@@ -39,8 +39,8 @@ SECTIONS {
     } .bss.prefix (NOLOAD) : AT ( _end_lma ) {
        _eprefix = .;
     }
-    _prefix_filesz     = ABSOLUTE ( _mprefix - _prefix );
-    _prefix_memsz      = ABSOLUTE ( _eprefix - _prefix );
+    _prefix_filesz     = ABSOLUTE ( _mprefix ) - ABSOLUTE ( _prefix );
+    _prefix_memsz      = ABSOLUTE ( _eprefix ) - ABSOLUTE ( _prefix );
 
     /*
      * The 16-bit (real-mode) code section
@@ -63,11 +63,11 @@ SECTIONS {
     } .bss.text16 (NOLOAD) : AT ( _end_lma ) {
        _etext16 = .;
     }
-    _text16_early_filesz = ABSOLUTE ( _etext16_early - _text16 );
-    _text16_early_memsz        = ABSOLUTE ( _etext16_early - _text16 );
-    _text16_late_filesz        = ABSOLUTE ( _mtext16 - _text16_late );
-    _text16_late_memsz = ABSOLUTE ( _etext16 - _text16_late );
-    _text16_memsz      = ABSOLUTE ( _etext16 - _text16 );
+    _text16_early_filesz = ABSOLUTE ( _etext16_early ) - ABSOLUTE ( _text16 );
+    _text16_early_memsz        = ABSOLUTE ( _etext16_early ) - ABSOLUTE ( _text16 );
+    _text16_late_filesz        = ABSOLUTE ( _mtext16 ) - ABSOLUTE ( _text16_late );
+    _text16_late_memsz = ABSOLUTE ( _etext16 ) - ABSOLUTE ( _text16_late );
+    _text16_memsz      = ABSOLUTE ( _etext16 ) - ABSOLUTE ( _text16 );
 
     /*
      * The 16-bit (real-mode) data section
@@ -89,8 +89,8 @@ SECTIONS {
        *(.stack16.*)
        _edata16 = .;
     }
-    _data16_filesz     = ABSOLUTE ( _mdata16 - _data16 );
-    _data16_memsz      = ABSOLUTE ( _edata16 - _data16 );
+    _data16_filesz     = ABSOLUTE ( _mdata16 ) - ABSOLUTE ( _data16 );
+    _data16_memsz      = ABSOLUTE ( _edata16 ) - ABSOLUTE ( _data16 );
 
     /*
      * The 32-bit sections
@@ -118,8 +118,8 @@ SECTIONS {
        *(.stack.*)
        _etextdata = .;
     }
-    _textdata_filesz   = ABSOLUTE ( _mtextdata - _textdata );
-    _textdata_memsz    = ABSOLUTE ( _etextdata - _textdata );
+    _textdata_filesz   = ABSOLUTE ( _mtextdata ) - ABSOLUTE ( _textdata );
+    _textdata_memsz    = ABSOLUTE ( _etextdata ) - ABSOLUTE ( _textdata );
 
     /*
      * Compressor information block
@@ -134,8 +134,8 @@ SECTIONS {
     } .bss.zinfo (NOLOAD) : AT ( _end_lma ) {
        _ezinfo = .;
     }
-    _zinfo_filesz      = ABSOLUTE ( _mzinfo - _zinfo );
-    _zinfo_memsz       = ABSOLUTE ( _ezinfo - _zinfo );
+    _zinfo_filesz      = ABSOLUTE ( _mzinfo ) - ABSOLUTE ( _zinfo );
+    _zinfo_memsz       = ABSOLUTE ( _ezinfo ) - ABSOLUTE ( _zinfo );
 
     /*
      * Weak symbols that need zero values if not otherwise defined