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Diffstat (limited to 'doc/README.SPL')
| -rw-r--r-- | doc/README.SPL | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/doc/README.SPL b/doc/README.SPL index e4a5ac3..4e1cb28 100644 --- a/doc/README.SPL +++ b/doc/README.SPL @@ -66,6 +66,7 @@ CONFIG_SPL_DMA_SUPPORT (drivers/dma/libdma.o) CONFIG_SPL_POST_MEM_SUPPORT (post/drivers/memory.o) CONFIG_SPL_NAND_LOAD (drivers/mtd/nand/nand_spl_load.o) CONFIG_SPL_SPI_LOAD (drivers/mtd/spi/spi_spl_load.o) +CONFIG_SPL_RAM_DEVICE (common/spl/spl.c) Normally CPU is assumed to be the same between the SPL and normal @@ -78,3 +79,33 @@ an SPL CPU in boards.cfg as follows: This this case CPU will be set to "normal_cpu" during the main u-boot build and "spl_cpu" during the SPL build. + + +Debugging +--------- + +When building SPL with DEBUG set you may also need to set CONFIG_PANIC_HANG +as in most cases do_reset is not defined within SPL. + + +Estimating stack usage +---------------------- + +With gcc 4.6 (and later) and the use of GNU cflow it is possible to estimate +stack usage at various points in run sequence of SPL. The -fstack-usage option +to gcc will produce '.su' files (such as arch/arm/cpu/armv7/syslib.su) that +will give stack usage information and cflow can construct program flow. + +Must have gcc 4.6 or later, which supports -fstack-usage + +1) Build normally +2) Perform the following shell command to generate a list of C files used in +SPL: +$ find spl -name '*.su' | sed -e 's:^spl/::' -e 's:[.]su$:.c:' > used-spl.list +3) Execute cflow: +$ cflow --main=board_init_r `cat used-spl.list` 2>&1 | $PAGER + +cflow will spit out a number of warnings as it does not parse +the config files and picks functions based on #ifdef. Parsing the '.i' +files instead introduces another set of headaches. These warnings are +not usually important to understanding the flow, however. |