On 11/21/2016 12:40 PM, Alexander Graf wrote: > > > 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 <[email protected]> >>> Signed-off-by: Alison Wang <[email protected]> >>> Signed-off-by: Chenhui Zhao <[email protected]> >>> --- >>> 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, Do you always load OS when calling armv8_switch_to_el2()? In this case of efi booting, kernel entry point needs to be passed to the new armv8_switch_to_el2 function. The new armv8_switch_to_el2 function doesn't return, so you cannot continue to run the code. York _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
