From 7f56e9a31c91099cd0147883a0282ec89ae0b346 Mon Sep 17 00:00:00 2001 From: Soby Mathew Date: Mon, 4 Sep 2017 11:49:29 +0100 Subject: Implement log framework This patch gives users control over logging messages printed from the C code using the LOG macros defined in debug.h Users now have the ability to reduce the log_level at run time using the tf_log_set_max_level() function. The default prefix string can be defined by platform by overriding the `plat_log_get_prefix()` platform API which is also introduced in this patch. The new log framework results in saving of some RO data. For example, when BL1 is built for FVP with LOG_LEVEL=LOG_LEVEL_VERBOSE, resulted in saving 384 bytes of RO data and increase of 8 bytes of RW data. The framework also adds about 108 bytes of code to the release build of FVP. Fixes ARM-software/tf-issues#462 Change-Id: I476013d9c3deedfdd4c8b0b0f125665ba6250554 Co-authored-by: Eleanor Bonnici Signed-off-by: Soby Mathew --- common/tf_log.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 common/tf_log.c (limited to 'common') diff --git a/common/tf_log.c b/common/tf_log.c new file mode 100644 index 000000000..54c0a4363 --- /dev/null +++ b/common/tf_log.c @@ -0,0 +1,61 @@ +/* + * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include +#include +#include + +/* Set the default maximum log level to the `LOG_LEVEL` build flag */ +static unsigned int max_log_level = LOG_LEVEL; + +/* + * The common log function which is invoked by ARM Trusted Firmware code. + * This function should not be directly invoked and is meant to be + * only used by the log macros defined in debug.h. The function + * expects the first character in the format string to be one of the + * LOG_MARKER_* macros defined in debug.h. + */ +void tf_log(const char *fmt, ...) +{ + unsigned int log_level; + va_list args; + const char *prefix_str; + + /* We expect the LOG_MARKER_* macro as the first character */ + log_level = fmt[0]; + + /* Verify that log_level is one of LOG_MARKER_* macro defined in debug.h */ + assert(log_level && log_level <= LOG_LEVEL_VERBOSE); + assert(log_level % 10 == 0); + + if (log_level > max_log_level) + return; + + prefix_str = plat_log_get_prefix(log_level); + + if (prefix_str != NULL) + tf_string_print(prefix_str); + + va_start(args, fmt); + tf_vprintf(fmt+1, args); + va_end(args); +} + +/* + * The helper function to set the log level dynamically by platform. The + * maximum log level is determined by `LOG_LEVEL` build flag at compile time + * and this helper can set a lower log level than the one at compile. + */ +void tf_log_set_max_level(unsigned int log_level) +{ + assert(log_level <= LOG_LEVEL_VERBOSE); + assert((log_level % 10) == 0); + + /* Cap log_level to the compile time maximum. */ + if (log_level < LOG_LEVEL) + max_log_level = log_level; + +} -- cgit v1.2.3