Convert CONFIG_BOOTCOUNT_EXT to Kconfig

[people/ms/u-boot.git] / doc / README.log

diff --git a/doc/README.log b/doc/README.log
index 54d9a8e1b90ea4f13418390522c49a6b86ed113d..dc9e2deec50602e4f8d53bbd00a3ba7b33a30792 100644 (file)
--- a/doc/README.log
+++ b/doc/README.log
@@ -51,6 +51,7 @@ The following main categories are defined:
    LOGC_BOARD  - Related to board-specific code
    LOGC_CORE   - Related to core driver-model support
    LOGC_DT     - Related to device tree control
+   LOGC_EFI    - Related to EFI implementation
 
 
 Enabling logging
@@ -148,6 +149,14 @@ Also debug() and error() will generate log records  - these use LOG_CATEGORY
 as the category, so you should #define this right at the top of the source
 file to ensure the category is correct.
 
+You can also define CONFIG_LOG_ERROR_RETURN to enable the log_ret() macro. This
+can be used whenever your function returns an error value:
+
+   return log_ret(uclass_first_device(UCLASS_MMC, &dev));
+
+This will write a log record when an error code is detected (a value < 0). This
+can make it easier to trace errors that are generated deep in the call stack.
+
 
 Code size
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