[PATCH] x86/boot: Handle better alignment for 32 bit code

[Frediano Ziglio <frediano.ziglio@cloud.com>]

Output file didn't have correct alignment.
Allows alignment into data or code up to 2mb.

Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
---
 xen/arch/x86/boot/Makefile        | 8 ++++----
 xen/tools/combine_two_binaries.py | 7 ++++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/boot/Makefile b/xen/arch/x86/boot/Makefile
index 13d4583173..9a8ecba7aa 100644
--- a/xen/arch/x86/boot/Makefile
+++ b/xen/arch/x86/boot/Makefile
@@ -40,8 +40,8 @@ LD32 := $(LD) $(subst x86_64,i386,$(LDFLAGS_DIRECT))
 # are affected by both text_diff and text_gap.  Ensure the sum of gap and diff
 # is greater than 2^16 so that any 16bit relocations if present in the object
 # file turns into a build-time error.
-text_gap := 0x010200
-text_diff := 0x408020
+text_gap := 0x01c240
+text_diff := 0x7e3dc0
 
 $(obj)/build32.base.lds: AFLAGS-y += -DGAP=$(text_gap) -DTEXT_DIFF=$(text_diff)
 $(obj)/build32.offset.lds: AFLAGS-y += -DGAP=$(text_gap) -DTEXT_DIFF=$(text_diff) -DAPPLY_OFFSET
@@ -69,7 +69,6 @@ $(obj)/built-in-32.%.bin: $(obj)/build32.%.lds $(obj)/built-in-32.tmp.o
 	$(LD32) $(orphan-handling-y) -N -T $< -o $(@:bin=o) $(filter %.o,$^)
 	$(NM) -p --format=bsd $(@:bin=o) > $(@:bin=map)
 	$(OBJCOPY) -j .text -O binary $(@:bin=o) $@
-	rm -f $(@:bin=o)
 
 quiet_cmd_combine = GEN     $@
 cmd_combine = \
@@ -80,6 +79,7 @@ cmd_combine = \
               --bin1      $(obj)/built-in-32.base.bin \
               --bin2      $(obj)/built-in-32.offset.bin \
               --map       $(obj)/built-in-32.base.map \
+              --align     $(shell $(OBJDUMP) -h $(obj)/built-in-32.base.o|sed '/text.*2\*\*/ {s/.*2\*\*//;p;}; d') \
               --exports   cmdline_parse_early,reloc,reloc_trampoline32 \
               --output    $@
 
@@ -90,4 +90,4 @@ $(obj)/built-in-32.S: $(obj)/built-in-32.base.bin $(obj)/built-in-32.offset.bin
                       $(srctree)/tools/combine_two_binaries.py FORCE
 	$(call if_changed,combine)
 
-clean-files := built-in-32.*.bin built-in-32.*.map build32.*.lds
+clean-files := built-in-32.*.bin built-in-32.*.map built-in-32.*.o build32.*.lds
diff --git a/xen/tools/combine_two_binaries.py b/xen/tools/combine_two_binaries.py
index 581e57cbc0..8e587c24fb 100755
--- a/xen/tools/combine_two_binaries.py
+++ b/xen/tools/combine_two_binaries.py
@@ -26,6 +26,10 @@ parser.add_argument('--text-diff', dest='text_diff',
                     required=True,
                     type=auto_int,
                     help='Difference between code section start')
+parser.add_argument('--align', dest='align',
+                    default=2,
+                    type=auto_int,
+                    help='Alignment in power of 2')
 parser.add_argument('--output', dest='output',
                     help='Output file')
 parser.add_argument('--map', dest='mapfile',
@@ -93,7 +97,7 @@ if size1 > size2:
     file1, file2 = file2, file1
     size1, size2 = size2, size1
 if size2 != size1 + gap:
-    raise Exception('File sizes do not match')
+    raise Exception('File sizes do not match %d != %d + %d' % (size2, size1, gap))
 del size2
 
 file1.seek(0, 0)
@@ -219,6 +223,7 @@ print('''/*
  * File autogenerated by combine_two_binaries.py DO NOT EDIT
  */''', file=out)
 print('\t' + args.section_header, file=out)
+print('\t.p2align\t' + str(args.align), file=out)
 print('obj32_start:', file=out)
 output(out)
 print('\n\t.section .note.GNU-stack,"",@progbits', file=out)
-- 
2.34.1