Cyril Chemparathy wrote:
The current ARM1176 CPU specific code is too specific to the SMDK6400 architecture. The following changes were necessary prerequisites for the addition of other SoCs based on ARM1176.
Existing board's (SMDK6400) configuration has been modified to keep behavior unchanged despite these changes.
- Peripheral port remap configurability
The earlier code had hardcoded remap values specific to s3c64xx in start.S. This change makes the peripheral port remap addresses and sizes configurable.
- Skip low level initialization
Ability to skip low level initialization if necessary. Many other platforms have a similar capability, and this is quite useful during debug/bring-up.
- U-Boot code relocation support
Most architectures allow u-boot code to run initially at a different address (possibly in NOR) and then get relocated to its final resting place in RAM. Added support for this capability in ARM1176 architecture.
- Disable TCM if necessary
If a ROM based bootloader happened to have initialized TCM, we disable it here to keep things sane.
- Remove unnecessary SoC specific includes
ARM1176 code does not really need this SoC specific include. The presence of this include prevents builds on other ARM1176 archs.
- ARM926 style MMU disable when !CONFIG_ENABLE_MMU
The original MMU disable code masks out too many bits from the load address when it tries to figure out the physical address of the jump target label. Consequently, it ends up branching to the wrong address after disabling the MMU.
Signed-off-by: Cyril Chemparathy cyril@ti.com
This patch is premature. I need to see this patch within the context of the new SOC.
For a new SOC, I would like it be added as a new sub dir off of cpu/arm1176. At the same level as s3c64xx. So this dir would look like.
config.mk cpu.c Makefile new_soc_name s3c64xx start.S u-boot.lds
The common code that is sharable should also be at this level. This may mean moving and generalizing some s3c64xx/*.c. The SOC specific code must be in its own dir. An example of this may be the lowlevel_init needs to move from start.S to <SOC>/lowlevel_init.S
I do not want one SOC if-def-ing up another SOC.
The maintainer of the original s3c64xx SOC, Guennadi Liakhovetski g.liakhovetski@gmx.de, should be cc-ed on at least the initial changes so he has a heads up that some of his code is being moved/generalized.
Tom