Select the Log Level for the Event Log Dump on Measured Boot at build time.

Builds in Debug mode with Measured Boot enabled might run out of trusted
SRAM. This patch allows to change the Log Level at which the Measured Boot
driver will dump the event log, so the latter can be accessed even on
Release builds if necessary, saving space on RAM.

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I133689e313776cb3f231b774c26cbca4760fa120

docs/getting_started/build-options.rst

@@ -300,6 +300,10 @@ Common build options
    handled at EL3, and a panic will result. This is supported only for AArch64
    builds.
 
+-  ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when
+   ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``.
+   Default value is 40 (LOG_LEVEL_INFO).
+
 -  ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault
    injection from lower ELs, and this build option enables lower ELs to use
    Error Records accessed via System Registers to inject faults. This is

drivers/measured_boot/measured_boot.mk

@@ -4,6 +4,9 @@
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
+# Default log level to dump the event log (LOG_LEVEL_INFO)
+EVENT_LOG_LEVEL         ?= 40
+
 # TPM hash algorithm
 TPM_HASH_ALG			:=	sha256
 
@@ -31,6 +34,7 @@ $(eval $(call add_defines,\
         TPM_ALG_ID \
         TCG_DIGEST_SIZE \
         EVENT_LOG_SIZE \
+        EVENT_LOG_LEVEL \
 )))
 
 ifeq (${HASH_ALG}, sha256)

include/drivers/measured_boot/event_log.h

@@ -20,8 +20,6 @@
  * LOG_LEVEL_WARNING
  * LOG_LEVEL_VERBOSE
  */
-#define	EVENT_LOG_LEVEL	LOG_LEVEL_INFO
-
 #if EVENT_LOG_LEVEL   == LOG_LEVEL_ERROR
 #define	LOG_EVENT	ERROR
 #elif EVENT_LOG_LEVEL == LOG_LEVEL_NOTICE