boot state: rebalance payload load vs actual boot

The notion of loading a payload in the current boot state
machine isn't actually loading the payload. The reason is
that cbfs is just walked to find the payload. The actual
loading and booting were occuring in selfboot(). Change this
balance so that loading occurs in one function and actual
booting happens in another. This allows for ample opportunity
to delay work until just before booting.

Change-Id: Ic91ed6050fc5d8bb90c8c33a44eea3b1ec84e32d
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/3139
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/include/cbfs.h

@@ -78,7 +78,8 @@ int run_address(void *f);
 
 /* Defined in src/lib/selfboot.c */
 struct lb_memory;
-int selfboot(struct lb_memory *mem, struct cbfs_payload *payload);
+void *selfload(struct lb_memory *mem, struct cbfs_payload *payload);
+void selfboot(void *entry);
 
 /* Defined in individual arch / board implementation. */
 int init_default_cbfs_media(struct cbfs_media *media);

src/lib/hardwaremain.c

@@ -198,6 +198,7 @@ static boot_state_t bs_write_tables(void *arg)
 static boot_state_t bs_payload_load(void *arg)
 {
 	void *payload;
+	void *entry;
 
 	timestamp_add_now(TS_LOAD_PAYLOAD);
 
@@ -206,15 +207,20 @@ static boot_state_t bs_payload_load(void *arg)
 	if (! payload)
 		die("Could not find a payload\n");
 
+	entry = selfload(get_lb_mem(), payload);
+
+	if (! entry)
+		die("Could not load payload\n");
+
 	/* Pass the payload to the next state. */
-	boot_states[BS_PAYLOAD_BOOT].arg = payload;
+	boot_states[BS_PAYLOAD_BOOT].arg = entry;
 
 	return BS_PAYLOAD_BOOT;
 }
 
-static boot_state_t bs_payload_boot(void *payload)
+static boot_state_t bs_payload_boot(void *entry)
 {
-	selfboot(get_lb_mem(), payload);
+	selfboot(entry);
 
 	printk(BIOS_EMERG, "Boot failed");
 	/* Returning from this state will fail because the following signals

src/lib/selfboot.c

@@ -512,7 +512,7 @@ static int load_self_segments(
 	return 1;
 }
 
-int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
+void *selfload(struct lb_memory *mem, struct cbfs_payload *payload)
 {
 	u32 entry=0;
 	struct segment head;
@@ -527,10 +527,18 @@ int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 
 	printk(BIOS_SPEW, "Loaded segments\n");
 
+	return (void *)entry;
+
+out:
+	return NULL;
+}
+
+void selfboot(void *entry)
+{
 	/* Reset to booting from this image as late as possible */
 	boot_successful();
 
-	printk(BIOS_DEBUG, "Jumping to boot code at %x\n", entry);
+	printk(BIOS_DEBUG, "Jumping to boot code at %p\n", entry);
 	post_code(POST_ENTER_ELF_BOOT);
 
 #if CONFIG_COLLECT_TIMESTAMPS
@@ -543,9 +551,5 @@ int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 	checkstack(_estack, 0);
 
 	/* Jump to kernel */
-	jmp_to_elf_entry((void*)entry, bounce_buffer, bounce_size);
-	return 1;
-
-out:
-	return 0;
+	jmp_to_elf_entry(entry, bounce_buffer, bounce_size);
 }