Add optional platform error handler API

This patch adds an optional API to the platform port:

    void plat_error_handler(int err) __dead2;

The platform error handler is called when there is a specific error
condition after which Trusted Firmware cannot continue. While panic()
simply prints the crash report (if enabled) and spins, the platform
error handler can be used to hand control over to the platform port
so it can perform specific bookeeping or post-error actions (for
example, reset the system). This function must not return.

The parameter indicates the type of error using standard codes from
errno.h. Possible errors reported by the generic code are:

    -EAUTH  : a certificate or image could not be authenticated
              (when Trusted Board Boot is enabled)
    -ENOENT : the requested image or certificate could not be found
              or an IO error was detected
    -ENOMEM : resources exhausted. Trusted Firmware does not use
              dynamic memory, so this error is usually an indication
              of an incorrect array size

A default weak implementation of this function has been provided.
It simply implements an infinite loop.

Change-Id: Iffaf9eee82d037da6caa43b3aed51df555e597a3

1 files changed, 1 insertions, 5 deletions

diff --git a/bl1/bl1_main.c b/bl1/bl1_main.c
index dad64e25..50cf4e0d 100644
--- a/bl1/bl1_main.c
+++ b/bl1/bl1_main.c
@@ -174,12 +174,8 @@ void bl1_main(void)
 			 &bl2_ep);
 
 	if (err) {
-		/*
-		 * TODO: print failure to load BL2 but also add a tzwdog timer
-		 * which will reset the system eventually.
-		 */
 		ERROR("Failed to load BL2 firmware.\n");
-		panic();
+		plat_error_handler(err);
 	}
 
 	/*