Blame view
doc/README.SPL
3.27 KB
6a11cf48a spl: add initial ... |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
Generic SPL framework ===================== Overview -------- To unify all existing implementations for a secondary program loader (SPL) and to allow simply adding of new implementations this generic SPL framework has been created. With this framework almost all source files for a board can be reused. No code duplication or symlinking is necessary anymore. How it works ------------ |
c01f87c8d doc: README.SPL: ... |
15 |
The object files for SPL are built separately and placed in the "spl" directory. |
6a11cf48a spl: add initial ... |
16 17 |
The final binaries which are generated are u-boot-spl, u-boot-spl.bin and u-boot-spl.map. |
c01f87c8d doc: README.SPL: ... |
18 |
A config option named CONFIG_SPL_BUILD is enabled by Kconfig for SPL. |
6a11cf48a spl: add initial ... |
19 |
Source files can therefore be compiled for SPL with different settings. |
6a11cf48a spl: add initial ... |
20 21 22 23 |
For example: ifeq ($(CONFIG_SPL_BUILD),y) |
c01f87c8d doc: README.SPL: ... |
24 |
obj-y += board_spl.o |
6a11cf48a spl: add initial ... |
25 |
else |
c01f87c8d doc: README.SPL: ... |
26 |
obj-y += board.o |
6a11cf48a spl: add initial ... |
27 |
endif |
c01f87c8d doc: README.SPL: ... |
28 |
obj-$(CONFIG_SPL_BUILD) += foo.o |
6a11cf48a spl: add initial ... |
29 30 |
#ifdef CONFIG_SPL_BUILD |
04e5ae793 Minor coding styl... |
31 |
foo(); |
6a11cf48a spl: add initial ... |
32 |
#endif |
c01f87c8d doc: README.SPL: ... |
33 |
The building of SPL images can be enabled by CONFIG_SPL option in Kconfig. |
6a11cf48a spl: add initial ... |
34 |
|
fd3d28e7a doc: fix typos |
35 36 |
Because SPL images normally have a different text base, one has to be configured by defining CONFIG_SPL_TEXT_BASE. The linker script has to be |
6a11cf48a spl: add initial ... |
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 |
defined with CONFIG_SPL_LDSCRIPT. To support generic U-Boot libraries and drivers in the SPL binary one can optionally define CONFIG_SPL_XXX_SUPPORT. Currently following options are supported: CONFIG_SPL_LIBCOMMON_SUPPORT (common/libcommon.o) CONFIG_SPL_LIBDISK_SUPPORT (disk/libdisk.o) CONFIG_SPL_I2C_SUPPORT (drivers/i2c/libi2c.o) CONFIG_SPL_GPIO_SUPPORT (drivers/gpio/libgpio.o) CONFIG_SPL_MMC_SUPPORT (drivers/mmc/libmmc.o) CONFIG_SPL_SERIAL_SUPPORT (drivers/serial/libserial.o) CONFIG_SPL_SPI_FLASH_SUPPORT (drivers/mtd/spi/libspi_flash.o) CONFIG_SPL_SPI_SUPPORT (drivers/spi/libspi.o) CONFIG_SPL_FAT_SUPPORT (fs/fat/libfat.o) |
fae81c72c doc: Update docum... |
52 |
CONFIG_SPL_EXT_SUPPORT |
6a11cf48a spl: add initial ... |
53 |
CONFIG_SPL_LIBGENERIC_SUPPORT (lib/libgeneric.o) |
682b3a81e spl: Add POWER li... |
54 |
CONFIG_SPL_POWER_SUPPORT (drivers/power/libpower.o) |
12c2f1ee3 spl: add NAND Lib... |
55 |
CONFIG_SPL_NAND_SUPPORT (drivers/mtd/nand/libnand.o) |
6609916ef powerpc:mpc85xx: ... |
56 |
CONFIG_SPL_DRIVERS_MISC_SUPPORT (drivers/misc) |
3a0d60c50 SPL: Add DMA library |
57 |
CONFIG_SPL_DMA_SUPPORT (drivers/dma/libdma.o) |
18e8ff18f spl: add option f... |
58 |
CONFIG_SPL_POST_MEM_SUPPORT (post/drivers/memory.o) |
435199f38 arm, davinci: add... |
59 |
CONFIG_SPL_NAND_LOAD (drivers/mtd/nand/nand_spl_load.o) |
32b112739 sf: Add spi_boot(... |
60 |
CONFIG_SPL_SPI_LOAD (drivers/mtd/spi/spi_spl_load.o) |
c57b953da SPL: Add support ... |
61 |
CONFIG_SPL_RAM_DEVICE (common/spl/spl.c) |
a09f96498 arm, spl: add wat... |
62 |
CONFIG_SPL_WATCHDOG_SUPPORT (drivers/watchdog/libwatchdog.o) |
d22650afa mkconfig: add sup... |
63 |
|
f8e754d51 README.SPL: Add a... |
64 65 66 67 68 69 |
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. |
c3567d808 README.SPL: Move ... |
70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 |
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. |