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-rw-r--r--README23
1 files changed, 23 insertions, 0 deletions
diff --git a/README b/README
index 7129df8..d072370 100644
--- a/README
+++ b/README
@@ -1000,6 +1000,7 @@ The following options need to be configured:
CONFIG_CMD_IMLS List all images found in NOR flash
CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
CONFIG_CMD_IMMAP * IMMR dump support
+ CONFIG_CMD_IOTRACE * I/O tracing for debugging
CONFIG_CMD_IMPORTENV * import an environment
CONFIG_CMD_INI * import data from an ini file into the env
CONFIG_CMD_IRQ * irqinfo
@@ -1171,6 +1172,28 @@ The following options need to be configured:
Note that if the GPIO device uses I2C, then the I2C interface
must also be configured. See I2C Support, below.
+- I/O tracing:
+ When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
+ accesses and can checksum them or write a list of them out
+ to memory. See the 'iotrace' command for details. This is
+ useful for testing device drivers since it can confirm that
+ the driver behaves the same way before and after a code
+ change. Currently this is supported on sandbox and arm. To
+ add support for your architecture, add '#include <iotrace.h>'
+ to the bottom of arch/<arch>/include/asm/io.h and test.
+
+ Example output from the 'iotrace stats' command is below.
+ Note that if the trace buffer is exhausted, the checksum will
+ still continue to operate.
+
+ iotrace is enabled
+ Start: 10000000 (buffer start address)
+ Size: 00010000 (buffer size)
+ Offset: 00000120 (current buffer offset)
+ Output: 10000120 (start + offset)
+ Count: 00000018 (number of trace records)
+ CRC32: 9526fb66 (CRC32 of all trace records)
+
- Timestamp Support:
When CONFIG_TIMESTAMP is selected, the timestamp