1bf457786SArd Biesheuvel /* 2bf457786SArd Biesheuvel * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> 3bf457786SArd Biesheuvel * 4bf457786SArd Biesheuvel * This file implements the EFI boot stub for the arm64 kernel. 5bf457786SArd Biesheuvel * Adapted from ARM version by Mark Salter <msalter@redhat.com> 6bf457786SArd Biesheuvel * 7bf457786SArd Biesheuvel * This program is free software; you can redistribute it and/or modify 8bf457786SArd Biesheuvel * it under the terms of the GNU General Public License version 2 as 9bf457786SArd Biesheuvel * published by the Free Software Foundation. 10bf457786SArd Biesheuvel * 11bf457786SArd Biesheuvel */ 12bf457786SArd Biesheuvel #include <linux/efi.h> 13bf457786SArd Biesheuvel #include <asm/efi.h> 14170976bcSMark Rutland #include <asm/memory.h> 15bf457786SArd Biesheuvel #include <asm/sections.h> 1642b55734SArd Biesheuvel #include <asm/sysreg.h> 17bf457786SArd Biesheuvel 182b5fe07aSArd Biesheuvel #include "efistub.h" 192b5fe07aSArd Biesheuvel 2042b55734SArd Biesheuvel efi_status_t check_platform_features(efi_system_table_t *sys_table_arg) 2142b55734SArd Biesheuvel { 2242b55734SArd Biesheuvel u64 tg; 2342b55734SArd Biesheuvel 2442b55734SArd Biesheuvel /* UEFI mandates support for 4 KB granularity, no need to check */ 2542b55734SArd Biesheuvel if (IS_ENABLED(CONFIG_ARM64_4K_PAGES)) 2642b55734SArd Biesheuvel return EFI_SUCCESS; 2742b55734SArd Biesheuvel 2842b55734SArd Biesheuvel tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf; 2942b55734SArd Biesheuvel if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) { 3042b55734SArd Biesheuvel if (IS_ENABLED(CONFIG_ARM64_64K_PAGES)) 3142b55734SArd Biesheuvel pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n"); 3242b55734SArd Biesheuvel else 3342b55734SArd Biesheuvel pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n"); 3442b55734SArd Biesheuvel return EFI_UNSUPPORTED; 3542b55734SArd Biesheuvel } 3642b55734SArd Biesheuvel return EFI_SUCCESS; 3742b55734SArd Biesheuvel } 38bf457786SArd Biesheuvel 39dae31fd2SArd Biesheuvel efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg, 40bf457786SArd Biesheuvel unsigned long *image_addr, 41bf457786SArd Biesheuvel unsigned long *image_size, 42bf457786SArd Biesheuvel unsigned long *reserve_addr, 43bf457786SArd Biesheuvel unsigned long *reserve_size, 44bf457786SArd Biesheuvel unsigned long dram_base, 45bf457786SArd Biesheuvel efi_loaded_image_t *image) 46bf457786SArd Biesheuvel { 47bf457786SArd Biesheuvel efi_status_t status; 48bf457786SArd Biesheuvel unsigned long kernel_size, kernel_memsize = 0; 49bf457786SArd Biesheuvel void *old_image_addr = (void *)*image_addr; 502dc10ad8SLinus Torvalds unsigned long preferred_offset; 512b5fe07aSArd Biesheuvel u64 phys_seed = 0; 522b5fe07aSArd Biesheuvel 532b5fe07aSArd Biesheuvel if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 5460f38de7SArd Biesheuvel if (!nokaslr()) { 552b5fe07aSArd Biesheuvel status = efi_get_random_bytes(sys_table_arg, 562b5fe07aSArd Biesheuvel sizeof(phys_seed), 572b5fe07aSArd Biesheuvel (u8 *)&phys_seed); 582b5fe07aSArd Biesheuvel if (status == EFI_NOT_FOUND) { 592b5fe07aSArd Biesheuvel pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n"); 602b5fe07aSArd Biesheuvel } else if (status != EFI_SUCCESS) { 612b5fe07aSArd Biesheuvel pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n"); 622b5fe07aSArd Biesheuvel return status; 632b5fe07aSArd Biesheuvel } 642b5fe07aSArd Biesheuvel } else { 652b5fe07aSArd Biesheuvel pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n"); 662b5fe07aSArd Biesheuvel } 672b5fe07aSArd Biesheuvel } 682dc10ad8SLinus Torvalds 692dc10ad8SLinus Torvalds /* 702dc10ad8SLinus Torvalds * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond 712dc10ad8SLinus Torvalds * a 2 MB aligned base, which itself may be lower than dram_base, as 722dc10ad8SLinus Torvalds * long as the resulting offset equals or exceeds it. 732dc10ad8SLinus Torvalds */ 742b5fe07aSArd Biesheuvel preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET; 752dc10ad8SLinus Torvalds if (preferred_offset < dram_base) 762b5fe07aSArd Biesheuvel preferred_offset += MIN_KIMG_ALIGN; 77bf457786SArd Biesheuvel 78bf457786SArd Biesheuvel kernel_size = _edata - _text; 79bf457786SArd Biesheuvel kernel_memsize = kernel_size + (_end - _edata); 80bf457786SArd Biesheuvel 812b5fe07aSArd Biesheuvel if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { 82bf457786SArd Biesheuvel /* 836f26b367SArd Biesheuvel * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a 846f26b367SArd Biesheuvel * displacement in the interval [0, MIN_KIMG_ALIGN) that 85170976bcSMark Rutland * doesn't violate this kernel's de-facto alignment 86170976bcSMark Rutland * constraints. 876f26b367SArd Biesheuvel */ 88170976bcSMark Rutland u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1); 896f26b367SArd Biesheuvel u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ? 906f26b367SArd Biesheuvel (phys_seed >> 32) & mask : TEXT_OFFSET; 916f26b367SArd Biesheuvel 926f26b367SArd Biesheuvel /* 932b5fe07aSArd Biesheuvel * If KASLR is enabled, and we have some randomness available, 942b5fe07aSArd Biesheuvel * locate the kernel at a randomized offset in physical memory. 952b5fe07aSArd Biesheuvel */ 966f26b367SArd Biesheuvel *reserve_size = kernel_memsize + offset; 972b5fe07aSArd Biesheuvel status = efi_random_alloc(sys_table_arg, *reserve_size, 982b5fe07aSArd Biesheuvel MIN_KIMG_ALIGN, reserve_addr, 996f26b367SArd Biesheuvel (u32)phys_seed); 1002b5fe07aSArd Biesheuvel 1016f26b367SArd Biesheuvel *image_addr = *reserve_addr + offset; 1022b5fe07aSArd Biesheuvel } else { 1032b5fe07aSArd Biesheuvel /* 1042b5fe07aSArd Biesheuvel * Else, try a straight allocation at the preferred offset. 105bf457786SArd Biesheuvel * This will work around the issue where, if dram_base == 0x0, 106bf457786SArd Biesheuvel * efi_low_alloc() refuses to allocate at 0x0 (to prevent the 107bf457786SArd Biesheuvel * address of the allocation to be mistaken for a FAIL return 108bf457786SArd Biesheuvel * value or a NULL pointer). It will also ensure that, on 109bf457786SArd Biesheuvel * platforms where the [dram_base, dram_base + TEXT_OFFSET) 110bf457786SArd Biesheuvel * interval is partially occupied by the firmware (like on APM 111bf457786SArd Biesheuvel * Mustang), we can still place the kernel at the address 112bf457786SArd Biesheuvel * 'dram_base + TEXT_OFFSET'. 113bf457786SArd Biesheuvel */ 1142b5fe07aSArd Biesheuvel if (*image_addr == preferred_offset) 1152b5fe07aSArd Biesheuvel return EFI_SUCCESS; 1162b5fe07aSArd Biesheuvel 1172dc10ad8SLinus Torvalds *image_addr = *reserve_addr = preferred_offset; 1182b5fe07aSArd Biesheuvel *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN); 1192b5fe07aSArd Biesheuvel 120bf457786SArd Biesheuvel status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, 1212b5fe07aSArd Biesheuvel EFI_LOADER_DATA, 1222b5fe07aSArd Biesheuvel *reserve_size / EFI_PAGE_SIZE, 123bf457786SArd Biesheuvel (efi_physical_addr_t *)reserve_addr); 1242b5fe07aSArd Biesheuvel } 1252b5fe07aSArd Biesheuvel 126bf457786SArd Biesheuvel if (status != EFI_SUCCESS) { 1272b5fe07aSArd Biesheuvel *reserve_size = kernel_memsize + TEXT_OFFSET; 1282b5fe07aSArd Biesheuvel status = efi_low_alloc(sys_table_arg, *reserve_size, 1292b5fe07aSArd Biesheuvel MIN_KIMG_ALIGN, reserve_addr); 130bf457786SArd Biesheuvel 131bf457786SArd Biesheuvel if (status != EFI_SUCCESS) { 132bf457786SArd Biesheuvel pr_efi_err(sys_table_arg, "Failed to relocate kernel\n"); 1332b5fe07aSArd Biesheuvel *reserve_size = 0; 134bf457786SArd Biesheuvel return status; 135bf457786SArd Biesheuvel } 136bf457786SArd Biesheuvel *image_addr = *reserve_addr + TEXT_OFFSET; 137bf457786SArd Biesheuvel } 138bf457786SArd Biesheuvel memcpy((void *)*image_addr, old_image_addr, kernel_size); 139bf457786SArd Biesheuvel 140bf457786SArd Biesheuvel return EFI_SUCCESS; 141bf457786SArd Biesheuvel } 142