Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> |
| 3 | * |
| 4 | * This file implements the EFI boot stub for the arm64 kernel. |
| 5 | * Adapted from ARM version by Mark Salter <msalter@redhat.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | */ |
Ard Biesheuvel | 94c47d4 | 2017-08-18 20:49:36 +0100 | [diff] [blame] | 12 | |
| 13 | /* |
| 14 | * To prevent the compiler from emitting GOT-indirected (and thus absolute) |
| 15 | * references to the section markers, override their visibility as 'hidden' |
| 16 | */ |
| 17 | #pragma GCC visibility push(hidden) |
| 18 | #include <asm/sections.h> |
| 19 | #pragma GCC visibility pop |
| 20 | |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 21 | #include <linux/efi.h> |
Ard Biesheuvel | a13b007 | 2014-07-02 14:54:41 +0200 | [diff] [blame] | 22 | #include <asm/efi.h> |
Ard Biesheuvel | 42b5573 | 2016-02-17 12:36:02 +0000 | [diff] [blame] | 23 | #include <asm/sysreg.h> |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 24 | |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 25 | #include "efistub.h" |
| 26 | |
| 27 | extern bool __nokaslr; |
| 28 | |
Ard Biesheuvel | 42b5573 | 2016-02-17 12:36:02 +0000 | [diff] [blame] | 29 | efi_status_t check_platform_features(efi_system_table_t *sys_table_arg) |
| 30 | { |
| 31 | u64 tg; |
| 32 | |
| 33 | /* UEFI mandates support for 4 KB granularity, no need to check */ |
| 34 | if (IS_ENABLED(CONFIG_ARM64_4K_PAGES)) |
| 35 | return EFI_SUCCESS; |
| 36 | |
| 37 | tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf; |
| 38 | if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) { |
| 39 | if (IS_ENABLED(CONFIG_ARM64_64K_PAGES)) |
| 40 | pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n"); |
| 41 | else |
| 42 | pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n"); |
| 43 | return EFI_UNSUPPORTED; |
| 44 | } |
| 45 | return EFI_SUCCESS; |
| 46 | } |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 47 | |
Ard Biesheuvel | dae31fd | 2016-02-17 12:35:57 +0000 | [diff] [blame] | 48 | efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg, |
| 49 | unsigned long *image_addr, |
| 50 | unsigned long *image_size, |
| 51 | unsigned long *reserve_addr, |
| 52 | unsigned long *reserve_size, |
| 53 | unsigned long dram_base, |
| 54 | efi_loaded_image_t *image) |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 55 | { |
| 56 | efi_status_t status; |
| 57 | unsigned long kernel_size, kernel_memsize = 0; |
Ard Biesheuvel | e38457c | 2015-07-24 12:38:27 +0100 | [diff] [blame] | 58 | void *old_image_addr = (void *)*image_addr; |
Ard Biesheuvel | 73effcc | 2015-10-29 15:07:25 +0100 | [diff] [blame] | 59 | unsigned long preferred_offset; |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 60 | u64 phys_seed = 0; |
| 61 | |
| 62 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
| 63 | if (!__nokaslr) { |
| 64 | status = efi_get_random_bytes(sys_table_arg, |
| 65 | sizeof(phys_seed), |
| 66 | (u8 *)&phys_seed); |
| 67 | if (status == EFI_NOT_FOUND) { |
| 68 | pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n"); |
| 69 | } else if (status != EFI_SUCCESS) { |
| 70 | pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n"); |
| 71 | return status; |
| 72 | } |
| 73 | } else { |
| 74 | pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n"); |
| 75 | } |
| 76 | } |
Ard Biesheuvel | 73effcc | 2015-10-29 15:07:25 +0100 | [diff] [blame] | 77 | |
| 78 | /* |
| 79 | * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond |
| 80 | * a 2 MB aligned base, which itself may be lower than dram_base, as |
| 81 | * long as the resulting offset equals or exceeds it. |
| 82 | */ |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 83 | preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET; |
Ard Biesheuvel | 73effcc | 2015-10-29 15:07:25 +0100 | [diff] [blame] | 84 | if (preferred_offset < dram_base) |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 85 | preferred_offset += MIN_KIMG_ALIGN; |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 86 | |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 87 | kernel_size = _edata - _text; |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 88 | kernel_memsize = kernel_size + (_end - _edata); |
Ard Biesheuvel | e38457c | 2015-07-24 12:38:27 +0100 | [diff] [blame] | 89 | |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 90 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { |
Ard Biesheuvel | e38457c | 2015-07-24 12:38:27 +0100 | [diff] [blame] | 91 | /* |
Ard Biesheuvel | 6f26b36 | 2016-04-18 17:09:48 +0200 | [diff] [blame] | 92 | * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a |
| 93 | * displacement in the interval [0, MIN_KIMG_ALIGN) that |
| 94 | * is a multiple of the minimal segment alignment (SZ_64K) |
| 95 | */ |
| 96 | u32 mask = (MIN_KIMG_ALIGN - 1) & ~(SZ_64K - 1); |
| 97 | u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ? |
| 98 | (phys_seed >> 32) & mask : TEXT_OFFSET; |
| 99 | |
| 100 | /* |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 101 | * If KASLR is enabled, and we have some randomness available, |
| 102 | * locate the kernel at a randomized offset in physical memory. |
| 103 | */ |
Ard Biesheuvel | 6f26b36 | 2016-04-18 17:09:48 +0200 | [diff] [blame] | 104 | *reserve_size = kernel_memsize + offset; |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 105 | status = efi_random_alloc(sys_table_arg, *reserve_size, |
| 106 | MIN_KIMG_ALIGN, reserve_addr, |
Ard Biesheuvel | 6f26b36 | 2016-04-18 17:09:48 +0200 | [diff] [blame] | 107 | (u32)phys_seed); |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 108 | |
Ard Biesheuvel | 6f26b36 | 2016-04-18 17:09:48 +0200 | [diff] [blame] | 109 | *image_addr = *reserve_addr + offset; |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 110 | } else { |
| 111 | /* |
| 112 | * Else, try a straight allocation at the preferred offset. |
Ard Biesheuvel | e38457c | 2015-07-24 12:38:27 +0100 | [diff] [blame] | 113 | * This will work around the issue where, if dram_base == 0x0, |
| 114 | * efi_low_alloc() refuses to allocate at 0x0 (to prevent the |
| 115 | * address of the allocation to be mistaken for a FAIL return |
| 116 | * value or a NULL pointer). It will also ensure that, on |
| 117 | * platforms where the [dram_base, dram_base + TEXT_OFFSET) |
| 118 | * interval is partially occupied by the firmware (like on APM |
| 119 | * Mustang), we can still place the kernel at the address |
| 120 | * 'dram_base + TEXT_OFFSET'. |
| 121 | */ |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 122 | if (*image_addr == preferred_offset) |
| 123 | return EFI_SUCCESS; |
Ard Biesheuvel | e38457c | 2015-07-24 12:38:27 +0100 | [diff] [blame] | 124 | |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 125 | *image_addr = *reserve_addr = preferred_offset; |
| 126 | *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN); |
| 127 | |
| 128 | status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, |
| 129 | EFI_LOADER_DATA, |
| 130 | *reserve_size / EFI_PAGE_SIZE, |
| 131 | (efi_physical_addr_t *)reserve_addr); |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 132 | } |
| 133 | |
Ard Biesheuvel | 2b5fe07 | 2016-01-26 14:48:29 +0100 | [diff] [blame] | 134 | if (status != EFI_SUCCESS) { |
| 135 | *reserve_size = kernel_memsize + TEXT_OFFSET; |
| 136 | status = efi_low_alloc(sys_table_arg, *reserve_size, |
| 137 | MIN_KIMG_ALIGN, reserve_addr); |
| 138 | |
| 139 | if (status != EFI_SUCCESS) { |
| 140 | pr_efi_err(sys_table_arg, "Failed to relocate kernel\n"); |
| 141 | *reserve_size = 0; |
| 142 | return status; |
| 143 | } |
| 144 | *image_addr = *reserve_addr + TEXT_OFFSET; |
| 145 | } |
| 146 | memcpy((void *)*image_addr, old_image_addr, kernel_size); |
Mark Salter | 3c7f255 | 2014-04-15 22:47:52 -0400 | [diff] [blame] | 147 | |
| 148 | return EFI_SUCCESS; |
| 149 | } |