TI816x U-Boot EA3
1
TI816x U- Boot EA3
U-Boot
In TI816x the ROM code serves as the first stage bootloader. The 2nd stage bootloader is based on U-Boot
[1]
. It
does the bare minimum configuration needed to boot the kernel and in the process relocates itself to DDR.
In case of NAND/SPI boot mode, the ROM code loads the U-Boot image from the flash memory into OCMC
RAM1. In case of NOR boot mode, the ROM code passes the control to the U-Boot image in NOR memory after
some basic initialization.
Size of U-Boot (TEXT + BSS section) cannot exceed 255KB (Applicable for all modes except SD boot mode.
For details refer here
Note
To avoid over-writing U-Boot when it is executing make sure that an address greater than 0x80800000 is used when
downloading the kernel and/or filesystem images
Building U-Boot
Note
The pre-built U-Boot binaries that comes in the release package has been built for DDR2 based EVM. The binaries
MLO and u-boot.bin are meant for SD boot and u-boot.noxip.bin is for flashing to NAND. The following steps can
be skipped if you have a DDR2 based EVM and wish to use the pre-built U-Boot image for flashing to NAND or if
you want to use SD boot.
Change to the base of the U-Boot directory.
$ cd ./u-boot
Remove the intermediate files generated during build. This step is not necessary when building for the first time.
$ make CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm distclean
NOTE: U-Boot can be built to boot out of NAND, NOR or SPI flash. The default behavior is to place the ENV
section of U-Boot (where the environment variables are stored) in the same media for which U-Boot was built.
If you want to build U-Boot for DDR3 based EVM make the following change in include/configs/ti8168_evm.h in
U-Boot source code:
#define CONFIG_TI816X_EVM_DDR2 ==> #undef CONFIG_TI816X_EVM_DDR2
#undef CONFIG_TI816X_EVM_DDR3 ==> #define CONFIG_TI816X_EVM_DDR3
Choose one of the following configuration for TI8168 EVM
Default target (built for NAND currently)
$ make CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm ti8168_evm_config
To explicitly select NAND boot
剩余23页未读，继续阅读
评论0