On 11/21/2016 01:07 PM, Alexander Graf wrote: > > > On 21/11/2016 21:45, york sun wrote: >> 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. > > We always call some random function pointer in the new flow. That can be > a kernel entry point, but it can also just be a function pointer. In > this case, the code would basically look like this: > > static ulong efi_run_in_el2(ulong (*entry), void *arg1, void *arg2) > { > dcache_enable(); > return entry(arg1, arg2); > } > > if (current_el() == 3) { > ... > return armv8_switch_to_el2(efi_run_in_el2, entry, > &loaded_image_info, &systab); > } >
Alex, Since you are most familiar with EFI boot code, can you send a patch to address this? I can squash it with Alison's patch after testing. My current test branch is http://git.denx.de/?p=u-boot/u-boot-fsl-qoriq.git;a=shortlog;h=refs/heads/test_qoriq. Thanks. York _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
