Clean up stack checking code

Several small improvements of the stack checking code:
- move the CPU0 stack check right before jumping to the payload
  and out of hardwaremain (that file is too crowded anyways)
- fix prototype in lib.h
- print size of used stack
- use checkstack function both on CPU0 and CPU1-x
- print amount of stack used per core

Signed-off-by: Stefan Reinauer <reinauer@google.com>

Test: Boot coreboot on Link, see the following output:
     ...
     CPU1: stack: 00156000 - 00157000, lowest used address 00156c68,
           stack used: 920 bytes
     CPU2: stack: 00155000 - 00156000, lowest used address 00155c68,
           stack used: 920 bytes
     CPU3: stack: 00154000 - 00155000, lowest used address 00154c68,
           stack used: 920 bytes
     ...
     Jumping to boot code at 1110008
     CPU0: stack: 00157000 - 00158000, lowest used address 00157af8,
           stack used: 1288 bytes

Change-Id: I7b83eeee0186559a0a62daa12e3f7782990fd2df
Reviewed-on: http://review.coreboot.org/1787
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/lib/stack.c b/src/lib/stack.c
index 3f04b63828af..0a6637f2560d 100644
--- a/src/lib/stack.c
+++ b/src/lib/stack.c
@@ -35,15 +35,17 @@ int checkstack(void *top_of_stack, int core)
 		return -1;
 	}
 
-	for(i = 0; i < CONFIG_STACK_SIZE/sizeof(stack[0]); i++){
+	for(i = 1; i < CONFIG_STACK_SIZE/sizeof(stack[0]); i++){
 		if (stack[i] == 0xDEADBEEF)
 			continue;
-		printk(BIOS_SPEW, "CPU%d: stack from %p to %p:",
-			core,
-			stack,
+		printk(BIOS_SPEW, "CPU%d: stack: %p - %p, ",
+			core, stack,
 			&stack[CONFIG_STACK_SIZE/sizeof(stack[0])]);
-		printk(BIOS_SPEW, "Lowest stack address %p\n", &stack[i]);
-		return -1;
+		printk(BIOS_SPEW, "lowest used address %p, ", &stack[i]);
+		printk(BIOS_SPEW, "stack used: %ld bytes\n",
+			(unsigned long)&stack[CONFIG_STACK_SIZE /
+			sizeof(stack[0])] - (unsigned long)&stack[i]);
+		return 0;
 	}
 
 	return 0;