[U-Boot] [PATCH v6 2/6] efi_loader: AArch64: Run EFI payloads in EL2 if U-Boot runs in EL3
Alexander Graf
agraf at suse.de
Wed Oct 19 16:31:13 CEST 2016
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 <agraf at suse.de>
Reviewed-by: York Sun <york.sun at nxp.com>
---
v4 -> v5:
- Remove manual ttbr / tcr copy
- Regenerate page tables in EL2, getting us non-secured page tables
---
cmd/bootefi.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index c8079c4..a9910d7 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -226,6 +226,17 @@ static unsigned long do_bootefi_exec(void *efi, void *fdt)
return status == EFI_SUCCESS ? 0 : -EINVAL;
}
+#ifdef CONFIG_ARM64
+ /* On AArch64 we need to make sure we call our payload in < EL3 */
+ if (current_el() == 3) {
+ smp_kick_all_cpus();
+ dcache_disable(); /* flush cache before switch to EL2 */
+ armv8_switch_to_el2();
+ /* Enable caches again */
+ dcache_enable();
+ }
+#endif
+
return entry(&loaded_image_info, &systab);
}
--
1.8.5.6
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