I think the boot0 hook is suppose to add some data in the very beginning of the SPL image, am I right?
Rockchip SoCs bootrom design is like this: - First 2KB or 4KB internal memory is for bootrom stack and heap; - Then the first 4-byte suppose to be a TAG like 'RK33'; - The the following memory address end with '0004' is the first instruction load and running by bootrom;
Example for RK3288: Before this patch set, the SPL_TEXT_BASE is ff704004, and image write to media device after mkimage like this:
ff704000: 32334b52 00000000 00000000 00000000 RK32............ ff704010: 00000000 00000000 00000000 00000000 ................ ff704020: ea00000f e59ff014 e59ff014 e59ff014 ................ ff704030: e59ff014 e59ff014 e59ff014 e59ff014 ................
Where the first instruction from bootrom is '00000000', which is a undefined instruction. The '_start' and 'reset' have to align to 0x20 for the requirement of VBAR, the memory offset '004'~'01c' are filled with '00000000'.
We can use the boot0 hook to fix this issue, after this patch set, the SPL_TEXT_BASE is ff704000 and image write to media device after mkimage like this:
ff704000: 32334b52 ea00001d e320f000 e320f000 RK32...... ... . ff704010: e320f000 e320f000 e320f000 e320f000 .. ... ... ... . ff704020: ea000016 e59ff014 e59ff014 e59ff014 ................ ff704030: e59ff014 e59ff014 e59ff014 e59ff014 ................
The first instruction from bootrom is a 'b reset', and memory of '008'~'01c' are filled with 'nop' instruction.
This patch set does not provide patch for socfpga, bcm and sunxi SoCs which also enable BOOT0_HOOK, so this is a RFC patch, please advice how to make it compatible with those three platforms.
Kever Yang (5): armv7: move boot hook before '_start' rockchip: boot0: align to 0x20 for armv7 '_start' rockchip: enable BOOT0_HOOK for SoCs rockchip: configs: use aligned address for SPL_TEXT_BASE rockchip: mkimage: use spl_boot0 for all Rockchip SoCs
arch/arm/include/asm/arch-rockchip/boot0.h | 9 ++++++++- arch/arm/lib/vectors.S | 19 ++++++++++--------- arch/arm/mach-rockchip/Kconfig | 3 +++ include/configs/rk3036_common.h | 2 +- include/configs/rk3288_common.h | 2 +- tools/rkcommon.c | 8 ++++---- 6 files changed, 27 insertions(+), 16 deletions(-)