[PATCH qemu v2 2/2] m68k: align bootinfo strings and data to 4 bytes

["Jason A. Donenfeld" <Jason@zx2c4.com>]

Various tools, such as kexec-tools and m68k-bootinfo, expect each
bootinfo entry to be aligned to 4 bytes, not 2 bytes. So adjust the
padding to fill this out as such.

Also, break apart the padding additions from the other field length
additions, so that it's more clear why these magic numbers are being
added, and comment them too.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 hw/m68k/bootinfo.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h
index bd8b212fd3..897162b818 100644
--- a/hw/m68k/bootinfo.h
+++ b/hw/m68k/bootinfo.h
@@ -48,13 +48,14 @@
         stw_phys(as, base, id); \
         base += 2; \
         stw_phys(as, base, \
-                 (sizeof(struct bi_record) + strlen(string) + 2) & ~1); \
+                 (sizeof(struct bi_record) + strlen(string) + \
+                  1 /* null termination */ + 3 /* padding */) & ~3); \
         base += 2; \
         for (i = 0; string[i]; i++) { \
             stb_phys(as, base++, string[i]); \
         } \
         stb_phys(as, base++, 0); \
-        base = (base + 1) & ~1; \
+        base = (base + 3) & ~3; \
     } while (0)
 
 #define BOOTINFODATA(as, base, id, data, len) \
@@ -63,13 +64,14 @@
         stw_phys(as, base, id); \
         base += 2; \
         stw_phys(as, base, \
-                 (sizeof(struct bi_record) + len + 3) & ~1); \
+                 (sizeof(struct bi_record) + len + \
+                  2 /* length field */ + 3 /* padding */) & ~3); \
         base += 2; \
         stw_phys(as, base, len); \
         base += 2; \
         for (i = 0; i < len; ++i) { \
             stb_phys(as, base++, data[i]); \
         } \
-        base = (base + 1) & ~1; \
+        base = (base + 3) & ~3; \
     } while (0)
 #endif
-- 
2.37.3