diff options
| author | Kinsey Moore <kinsey.moore@oarcorp.com> | 2021-06-17 14:02:30 -0600 |
|---|---|---|
| committer | Gedare Bloom <gedare@rtems.org> | 2021-06-24 09:37:31 -0600 |
| commit | e613068ee6f4222ffa44790419e257235153f789 (patch) | |
| tree | 5eeb9f3687c5bf0fb6230a8edb23410c5e904203 | |
| parent | aarch64/xilinx-versal: new BSPs for qemu and vck190 (diff) | |
| download | rtems-e613068ee6f4222ffa44790419e257235153f789.tar.bz2 | |
aarch64: add support to drop EL3 to EL2
| -rw-r--r-- | bsps/aarch64/shared/start/start.S | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/bsps/aarch64/shared/start/start.S b/bsps/aarch64/shared/start/start.S index 3751545ee1..d0d9c2160a 100644 --- a/bsps/aarch64/shared/start/start.S +++ b/bsps/aarch64/shared/start/start.S @@ -98,7 +98,32 @@ _start: #endif msr SCTLR_EL1, x0 -#ifdef BSP_START_IN_HYP_SUPPORT +#ifdef BSP_START_IN_MON_SUPPORT + /* Drop from EL3 to EL2 */ + + /* Initialize HCR_EL2 and SCTLR_EL2 */ + msr HCR_EL2, XZR + msr SCTLR_EL2, XZR + /* Set EL2 Execution state via SCR_EL3 */ + mrs x0, SCR_EL3 + /* Set EL2 to AArch64 */ + orr x0, x0, #(1<<10) + /* Set EL1 to NS */ + orr x0, x0, #1 + msr SCR_EL3, x0 + + /* set EL2h mode for eret */ + mov x0, #0b01001 + msr SPSR_EL3, x0 + + /* Set EL2 entry point */ + adr x0, _el2_start + msr ELR_EL3, x0 + eret +#endif + +#if defined(BSP_START_IN_HYP_SUPPORT) || defined(BSP_START_IN_MON_SUPPORT) +_el2_start: /* Drop from EL2 to EL1 */ /* Configure HCR_EL2 */ |