On 21/11/2016 21:23, york sun wrote:
On 11/09/2016 07:02 PM, Alison Wang wrote:
To support loading a 32-bit OS, the execution state will change from AArch64 to AArch32 when jumping to kernel.
The architecture information will be got through checking FIT image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
Signed-off-by: Ebony Zhu ebony.zhu@nxp.com Signed-off-by: Alison Wang alison.wang@nxp.com Signed-off-by: Chenhui Zhao chenhui.zhao@nxp.com
Changes in v8:
- Fix the issue when U-Boot is running in EL2 or EL1.
Alison,
There is a conflict when merging with upstream code. Alex Graf merged his change to support EFI booting. See commit 69bd459d343fe1e5a68a6f187d8c99c78c6fc6ce. Specifically these lines
if (current_el() == 3) { smp_kick_all_cpus(); dcache_disable(); armv8_switch_to_el2(); dcache_enable(); }Function armv8_switch_to_el2() didn't take any argument before you change. With your proposed change to support 32-bit OS, you added arguments to this function, and presume this function always load OS. This may be flawed. Would it be possible to keep armv8_switch_to_el2() but introduce another function to carry out switching EL while loading OS?
Alison introduced it based on my comments - and I'd prefer if we only have the function call based version :).
It should be reasonably straight forward to move to it here. Just create a new helper stub that enables the dcache and calls entry().
Alex