diff mbox series

[PULL,3/3] m68k: align bootinfo strings and data to 4 bytes

Message ID 20220927062633.618677-4-laurent@vivier.eu (mailing list archive)
State New, archived
Headers show
Series [PULL,1/3] target/m68k: increase size of m68k CPU features from uint32_t to uint64_t | expand

Commit Message

Laurent Vivier Sept. 27, 2022, 6:26 a.m. UTC 
From: "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>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220926113900.1256630-2-Jason@zx2c4.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 hw/m68k/bootinfo.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h
index bd8b212fd35c..897162b8189c 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