Move cmos.default handling to bootblock

The cmos.default code wasn't actually used so far, due to an oversight
when forward-porting this feature from an old branch.

- Extend walkcbfs' use by factoring out the stage handling into C code.
- New sanitize_cmos() function that looks if CMOS data is invalid and
  cmos.default exists and if so overwrites CMOS with cmos.default data.
- Use sanitize_cmos() in both bootblock implementations.
- Drop the need to reboot after writing CMOS: CMOS wasn't used so far,
  so we can go on without a reboot.
- Remove the restriction that cmos.default only works on CAR boards.
- Always build in cmos.default support on boards that
  USE_OPTION_TABLE.

Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Acked-by: Stefan Reinauer <stefan.reinauer@coreboot.org>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6436 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/arch/x86/lib/walkcbfs.S

@@ -15,19 +15,13 @@
 
 #define CBFS_FILE_STRUCTSIZE (CBFS_FILE_OFFSET + 4)
 
-#define CBFS_STAGE_COMPRESSION 0
-#define CBFS_STAGE_ENTRY (CBFS_STAGE_COMPRESSION + 4)
-#define CBFS_STAGE_LOAD (CBFS_STAGE_ENTRY + 8)
-#define CBFS_STAGE_LEN (CBFS_STAGE_LOAD + 8)
-#define CBFS_STAGE_MEMLEN (CBFS_STAGE_LEN + 4)
-
 /*
   input %esi: filename
   input %esp: return address (not pointer to return address!)
   output %eax: entry point
   clobbers %ebx, %ecx, %edi
 */
-walkcbfs:
+walkcbfs_asm:
 	cld
 
 	mov CBFS_HEADER_PTR, %eax
@@ -67,8 +61,6 @@ walker:
 	mov CBFS_FILE_OFFSET(%ebx), %eax
 	bswap %eax
 	add %ebx, %eax
-	add $CBFS_STAGE_ENTRY, %eax /* eax = ((cbfs_stage* (cbfs_file* ebx)->offset)->entry) */
-	mov 0(%eax), %eax
 	jmp *%esp
 
 tryharder: