Align data segment using SEGMENT_SIZE

[Alan Modra <amodra at bigpond dot net dot au>]

The aim of this patch is to allow Jakub's DATA_SEGMENT_ALIGN idea to
work on targets like powerpc64-linux where we want text and data to
reside in separate 256M address ranges.  I originally extended the
DATA_SEGMENT_ALIGN token to take an extra "alignment" parameter (which
is why I was poking around in ldexp.c), then realized that I could do
the same thing in the script.  The trick is to handle the
COMMONPAGESIZE case by first moving "dot" up to the same address
within a page just below the SEGMENT_SIZE alignment address.

	* genscripts.sh (SEGMENT_SIZE): Use MAXPAGESIZE before
	TARGET_PAGE_SIZE.
	* scripttempl/elf.sc (DATA_SEGMENT_ALIGN): Incorporate
	SEGMENT_SIZE alignment.
	* emulparams/elf64ppc.sh (DATA_ADDR): Delete.
	(SEGMENT_SIZE): Define.

Applying mainline, but not the branch just yet as I have a sneaking
suspicion that DATA_SEGMENT_ALIGN is responsible for a report I
received about "stubs don't match calculated size" on powerpc64-linux.

Index: ld/genscripts.sh
===================================================================
RCS file: /cvs/src/src/ld/genscripts.sh,v
retrieving revision 1.9
diff -u -p -r1.9 genscripts.sh
--- ld/genscripts.sh	22 May 2002 08:44:50 -0000	1.9
+++ ld/genscripts.sh	25 Sep 2002 02:43:49 -0000
@@ -90,7 +90,7 @@ if [ "x$SCRIPT_NAME" = "xelf" ]; then
   GENERATE_COMBRELOC_SCRIPT=yes
 fi
 
-SEGMENT_SIZE=${SEGMENT_SIZE-${TARGET_PAGE_SIZE}}
+SEGMENT_SIZE=${SEGMENT_SIZE-${MAXPAGESIZE-${TARGET_PAGE_SIZE}}}
 
 # Determine DATA_ALIGNMENT for the 5 variants, using
 # values specified in the emulparams/<emulation>.sh file or default.
Index: ld/emulparams/elf64ppc.sh
===================================================================
RCS file: /cvs/src/src/ld/emulparams/elf64ppc.sh,v
retrieving revision 1.7
diff -u -p -r1.7 elf64ppc.sh
--- ld/emulparams/elf64ppc.sh	24 Sep 2002 04:02:03 -0000	1.7
+++ ld/emulparams/elf64ppc.sh	25 Sep 2002 02:43:50 -0000
@@ -5,7 +5,7 @@ GENERATE_SHLIB_SCRIPT=yes
 SCRIPT_NAME=elf
 OUTPUT_FORMAT="elf64-powerpc"
 TEXT_START_ADDR=0x10000000
-DATA_ADDR="ALIGN (0x10000000) + (. & (${MAXPAGESIZE} - 1))"
+SEGMENT_SIZE=0x10000000
 MAXPAGESIZE=0x40000
 COMMONPAGESIZE=0x1000
 ARCH=powerpc:common64
Index: ld/scripttempl/elf.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/elf.sc,v
retrieving revision 1.34
diff -u -p -r1.34 elf.sc
--- ld/scripttempl/elf.sc	1 Aug 2002 14:02:59 -0000	1.34
+++ ld/scripttempl/elf.sc	25 Sep 2002 02:43:50 -0000
@@ -74,10 +74,10 @@ test -z "${ALIGNMENT}" && ALIGNMENT="${E
 test "$LD_FLAG" = "N" && DATA_ADDR=.
 test -n "$CREATE_SHLIB" && test -n "$SHLIB_DATA_ADDR" && COMMONPAGESIZE=""
 test -z "$CREATE_SHLIB" && test -n "$DATA_ADDR" && COMMONPAGESIZE=""
-DATA_SEGMENT_ALIGN="ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1))"
+DATA_SEGMENT_ALIGN="ALIGN(${SEGMENT_SIZE}) + (. & (${MAXPAGESIZE} - 1))"
 DATA_SEGMENT_END=""
 if test -n "${COMMONPAGESIZE}"; then
-  DATA_SEGMENT_ALIGN="DATA_SEGMENT_ALIGN(${MAXPAGESIZE}, ${COMMONPAGESIZE})"
+  DATA_SEGMENT_ALIGN="ALIGN (${SEGMENT_SIZE}) - ((${MAXPAGESIZE} - .) & (${MAXPAGESIZE} - 1)); . = DATA_SEGMENT_ALIGN (${MAXPAGESIZE}, ${COMMONPAGESIZE})"
   DATA_SEGMENT_END=". = DATA_SEGMENT_END (.);"
 fi
 INTERP=".interp       ${RELOCATING-0} : { *(.interp) }"

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre