build: fix .text section address alignment

Some linkers verify that sections have a start address that is aligned
with the minimum alignment of that section.  Add extra padding to the
".text" section to ensure it is always aligned with the maximum
alignment of any section placed in ".text".

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported by: Ed Maste <emaste@FreeBSD.org>

(cherry picked from commit 3910de0dee216d5b5bf23cfa29bfc80d082b2ee7)

diff --git a/scripts/layoutrom.py b/scripts/layoutrom.py
index b976fb0564d86e9a96b4752f09a6deb0a81228a7..6616721d1b584892074491b292bac669c33ef104 100755 (executable)
--- a/scripts/layoutrom.py
+++ b/scripts/layoutrom.py
@@ -34,18 +34,22 @@ COMMONTRAILER = """
 # Determine section locations
 ######################################################################
 
-# Align 'pos' to 'alignbytes' offset
+# Align 'pos' up to 'alignbytes' offset
 def alignpos(pos, alignbytes):
     mask = alignbytes - 1
     return (pos + mask) & ~mask
 
+# Align 'pos' down to 'alignbytes' offset
+def aligndown(pos, alignbytes):
+    mask = alignbytes - 1
+    return pos & ~mask
+
 # Determine the final addresses for a list of sections that end at an
 # address.
 def setSectionsStart(sections, endaddr, minalign=1, segoffset=0):
     totspace = 0
     for section in sections:
-        if section.align > minalign:
-            minalign = section.align
+        minalign = max(minalign, section.align)
         totspace = alignpos(totspace, section.align) + section.size
     startaddr = int((endaddr - totspace) / minalign) * minalign
     curaddr = startaddr
@@ -269,7 +273,7 @@ def doLayout(sections, config, genreloc):
         final_sec32low_end = BUILD_LOWRAM_END
         zonelow_base = final_sec32low_end - 64*1024
     relocdelta = final_sec32low_end - sec32low_end
-    li.sec32low_start, li.sec32low_align = setSectionsStart(
+    li.sec32low_start, sec32low_align = setSectionsStart(
         sections32low, sec32low_end, 16
         , segoffset=zonelow_base - relocdelta)
     li.sec32low_end = sec32low_end
@@ -405,6 +409,8 @@ def writeLinkerScripts(li, out16, out32seg, out32flat):
     if li.config.get('CONFIG_MULTIBOOT'):
         multiboot_header = "LONG(0x1BADB002) LONG(0) LONG(-0x1BADB002)"
         sec32all_start -= 3 * 4
+    sec32all_align = max([section.align for section in li.sections])
+    sec32all_start = aligndown(sec32all_start, sec32all_align)
     out += outXRefs(filesections32flat, exportsyms=[li.entrysym]) + """
     _reloc_min_align = 0x%x ;
     zonefseg_start = 0x%x ;