diff options
Diffstat (limited to 'arch/arm64/kernel/start.S')
| -rw-r--r-- | arch/arm64/kernel/start.S | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/arch/arm64/kernel/start.S b/arch/arm64/kernel/start.S index 3cf58d2..2a5e2ae 100644 --- a/arch/arm64/kernel/start.S +++ b/arch/arm64/kernel/start.S @@ -38,12 +38,16 @@ reset: /* keep the dtb pointer before anything clobbers x0 */ mov x19, x0 - /* park secondary cores, they have nothing to do yet */ + /* + * park secondary cores, they have nothing to do yet. at + * EL3 they still get the monitor: a firmware call on any + * PE must land in a handler, a secondary with no EL3 + * vectors traps into nothing. + */ mrs x0, mpidr_el1 and x0, x0, #0xff - cbnz x0, park + cbnz x0, secondary_boot - /* which EL are we in, 0x8 per level shifted into bits 3:2 */ mrs x0, CurrentEL lsr x0, x0, #2 cmp x0, #3 @@ -54,12 +58,34 @@ reset: b.eq mmu_check b park +secondary_boot: + mrs x0, CurrentEL + lsr x0, x0, #2 + cmp x0, #3 + b.ne park + /* + * the same security state as the primary: SCR_EL3.NS + * clear leaves a PE secure, and a secondary released + * into the kernel secure is the inconsistent mode boot + * the kernel warns about, its calls trap to EL3 as if + * they were firmware's own. + */ + mrs x0, scr_el3 + orr x0, x0, #1 + msr scr_el3, x0 + isb + bl tb_monitor_init + b park + from_el3: /* - * EL3 holds the security state. the kernel runs non-secure, so - * set SCR_EL3.NS before dropping to EL2, which the kernel - * prefers (booting.rst, EL2 RECOMMENDED). + * EL3 holds the security state, so the monitor lives here: + * vectors, its own stack, the SMC conduit. it is resident + * after this, the kernel's firmware calls trap into it. */ + bl tb_monitor_init + + /* the kernel runs non-secure, drop to the EL2 it prefers */ mrs x0, scr_el3 orr x0, x0, #1 /* SCR_EL3.NS = 1, non-secure */ msr scr_el3, x0 |