diff options
Diffstat (limited to 'arch/arm64/kernel/efi-entry.S')
| -rw-r--r-- | arch/arm64/kernel/efi-entry.S | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm64/kernel/efi-entry.S b/arch/arm64/kernel/efi-entry.S new file mode 100644 index 000000000..0073b24b5 --- /dev/null +++ b/arch/arm64/kernel/efi-entry.S @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * EFI entry point. + * + * Copyright (C) 2013, 2014 Red Hat, Inc. + * Author: Mark Salter <msalter@redhat.com> + */ +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/assembler.h> + + __INIT + +SYM_CODE_START(efi_enter_kernel) + /* + * efi_pe_entry() will have copied the kernel image if necessary and we + * end up here with device tree address in x1 and the kernel entry + * point stored in x0. Save those values in registers which are + * callee preserved. + */ + ldr w2, =primary_entry_offset + add x19, x0, x2 // relocated Image entrypoint + mov x20, x1 // DTB address + + /* + * Clean the copied Image to the PoC, and ensure it is not shadowed by + * stale icache entries from before relocation. + */ + ldr w1, =kernel_size + bl __clean_dcache_area_poc + ic ialluis + + /* + * Clean the remainder of this routine to the PoC + * so that we can safely disable the MMU and caches. + */ + adr x0, 0f + ldr w1, 3f + bl __clean_dcache_area_poc +0: + /* Turn off Dcache and MMU */ + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL2 + b.ne 1f + mrs x0, sctlr_el2 + bic x0, x0, #1 << 0 // clear SCTLR.M + bic x0, x0, #1 << 2 // clear SCTLR.C + pre_disable_mmu_workaround + msr sctlr_el2, x0 + isb + b 2f +1: + mrs x0, sctlr_el1 + bic x0, x0, #1 << 0 // clear SCTLR.M + bic x0, x0, #1 << 2 // clear SCTLR.C + pre_disable_mmu_workaround + msr sctlr_el1, x0 + isb +2: + /* Jump to kernel entry point */ + mov x0, x20 + mov x1, xzr + mov x2, xzr + mov x3, xzr + br x19 +SYM_CODE_END(efi_enter_kernel) +3: .long . - 0b |