On 06/20/2016 04:07 PM, Alexander Graf wrote:
> Some boards decided not to run ATF or other secure firmware in EL3, so
> they instead run U-Boot there. The uEFI spec doesn't know what EL3 is
> though - it only knows about EL2 and EL1. So if we see that we're running
> in EL3, let's get into EL2 to make payloads happy.
>
> Signed-off-by: Alexander Graf <ag...@suse.de>
> ---
> arch/arm/include/asm/armv8/mmu.h | 19 ++++++++++++-------
> cmd/bootefi.c | 11 +++++++++++
> 2 files changed, 23 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/include/asm/armv8/mmu.h
> b/arch/arm/include/asm/armv8/mmu.h
> index 0d08ed3..876a2b2 100644
> --- a/arch/arm/include/asm/armv8/mmu.h
> +++ b/arch/arm/include/asm/armv8/mmu.h
> @@ -116,19 +116,24 @@
> static inline void set_ttbr_tcr_mair(int el, u64 table, u64 tcr, u64 attr)
> {
> asm volatile("dsb sy");
> - if (el == 1) {
> + switch (el) {
> + case 1:
> asm volatile("msr ttbr0_el1, %0" : : "r" (table) : "memory");
> asm volatile("msr tcr_el1, %0" : : "r" (tcr) : "memory");
> asm volatile("msr mair_el1, %0" : : "r" (attr) : "memory");
> - } else if (el == 2) {
> - asm volatile("msr ttbr0_el2, %0" : : "r" (table) : "memory");
> - asm volatile("msr tcr_el2, %0" : : "r" (tcr) : "memory");
> - asm volatile("msr mair_el2, %0" : : "r" (attr) : "memory");
> - } else if (el == 3) {
> + break;
> + case 3:
> asm volatile("msr ttbr0_el3, %0" : : "r" (table) : "memory");
> asm volatile("msr tcr_el3, %0" : : "r" (tcr) : "memory");
> asm volatile("msr mair_el3, %0" : : "r" (attr) : "memory");
> - } else {
> +
> + /* We may switch to EL2 later, so set those too; fall through */
> + case 2:
> + asm volatile("msr ttbr0_el2, %0" : : "r" (table) : "memory");
> + asm volatile("msr tcr_el2, %0" : : "r" (tcr) : "memory");
> + asm volatile("msr mair_el2, %0" : : "r" (attr) : "memory");
> + break;
This may be problematic. If we use secure memory for EL3, the MMU tables
have to be within the secure memory. But EL2 will not be able to access
it. I believe you have verified this patch set actually work. I am
curious how it work.
York
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
