diff options
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index c79db44ba128..434a16982e34 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -1410,7 +1410,11 @@ memdump: mov r12, r0 __hyp_reentry_vectors: W(b) . @ reset W(b) . @ undef +#ifdef CONFIG_EFI_STUB + W(b) __enter_kernel_from_hyp @ hvc from HYP +#else W(b) . @ svc +#endif W(b) . @ pabort W(b) . @ dabort W(b) __enter_kernel @ hyp @@ -1429,14 +1433,72 @@ __enter_kernel: reloc_code_end: #ifdef CONFIG_EFI_STUB +__enter_kernel_from_hyp: + mrc p15, 4, r0, c1, c0, 0 @ read HSCTLR + bic r0, r0, #0x5 @ disable MMU and caches + mcr p15, 4, r0, c1, c0, 0 @ write HSCTLR + isb + b __enter_kernel + ENTRY(efi_enter_kernel) mov r4, r0 @ preserve image base mov r8, r1 @ preserve DT pointer + ARM( adrl r0, call_cache_fn ) + THUMB( adr r0, call_cache_fn ) + adr r1, 0f @ clean the region of code we + bl cache_clean_flush @ may run with the MMU off + +#ifdef CONFIG_ARM_VIRT_EXT + @ + @ The EFI spec does not support booting on ARM in HYP mode, + @ since it mandates that the MMU and caches are on, with all + @ 32-bit addressable DRAM mapped 1:1 using short descriptors. + @ + @ While the EDK2 reference implementation adheres to this, + @ U-Boot might decide to enter the EFI stub in HYP mode + @ anyway, with the MMU and caches either on or off. + @ + mrs r0, cpsr @ get the current mode + msr spsr_cxsf, r0 @ record boot mode + and r0, r0, #MODE_MASK @ are we running in HYP mode? + cmp r0, #HYP_MODE + bne .Lefi_svc + + mrc p15, 4, r1, c1, c0, 0 @ read HSCTLR + tst r1, #0x1 @ MMU enabled at HYP? + beq 1f + + @ + @ When running in HYP mode with the caches on, we're better + @ off just carrying on using the cached 1:1 mapping that the + @ firmware provided. Set up the HYP vectors so HVC instructions + @ issued from HYP mode take us to the correct handler code. We + @ will disable the MMU before jumping to the kernel proper. + @ + adr r0, __hyp_reentry_vectors + mcr p15, 4, r0, c12, c0, 0 @ set HYP vector base (HVBAR) + isb + b .Lefi_hyp + + @ + @ When running in HYP mode with the caches off, we need to drop + @ into SVC mode now, and let the decompressor set up its cached + @ 1:1 mapping as usual. + @ +1: mov r9, r4 @ preserve image base + bl __hyp_stub_install @ install HYP stub vectors + safe_svcmode_maskall r1 @ drop to SVC mode + msr spsr_cxsf, r0 @ record boot mode + orr r4, r9, #1 @ restore image base and set LSB + b .Lefi_hyp +.Lefi_svc: +#endif mrc p15, 0, r0, c1, c0, 0 @ read SCTLR tst r0, #0x1 @ MMU enabled? orreq r4, r4, #1 @ set LSB if not +.Lefi_hyp: mov r0, r8 @ DT start add r1, r8, r2 @ DT end bl cache_clean_flush |