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4febfb8d | 1 | // SPDX-License-Identifier: GPL-2.0 |
3c7f2550 MS |
2 | /* |
3 | * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> | |
4 | * | |
5 | * This file implements the EFI boot stub for the arm64 kernel. | |
6 | * Adapted from ARM version by Mark Salter <msalter@redhat.com> | |
3c7f2550 | 7 | */ |
0426a4e6 | 8 | |
0426a4e6 | 9 | |
3c7f2550 | 10 | #include <linux/efi.h> |
a13b0077 | 11 | #include <asm/efi.h> |
170976bc | 12 | #include <asm/memory.h> |
6f05106e | 13 | #include <asm/sections.h> |
42b55734 | 14 | #include <asm/sysreg.h> |
3c7f2550 | 15 | |
2b5fe07a AB |
16 | #include "efistub.h" |
17 | ||
cd33a5c1 | 18 | efi_status_t check_platform_features(void) |
42b55734 AB |
19 | { |
20 | u64 tg; | |
21 | ||
22 | /* UEFI mandates support for 4 KB granularity, no need to check */ | |
23 | if (IS_ENABLED(CONFIG_ARM64_4K_PAGES)) | |
24 | return EFI_SUCCESS; | |
25 | ||
26 | tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf; | |
26f55386 | 27 | if (tg < ID_AA64MMFR0_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_TGRAN_SUPPORTED_MAX) { |
42b55734 | 28 | if (IS_ENABLED(CONFIG_ARM64_64K_PAGES)) |
793473c2 | 29 | efi_err("This 64 KB granular kernel is not supported by your CPU\n"); |
42b55734 | 30 | else |
793473c2 | 31 | efi_err("This 16 KB granular kernel is not supported by your CPU\n"); |
42b55734 AB |
32 | return EFI_UNSUPPORTED; |
33 | } | |
34 | return EFI_SUCCESS; | |
35 | } | |
3c7f2550 | 36 | |
5b94046e AB |
37 | /* |
38 | * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail | |
39 | * to provide space, and fail to zero it). Check for this condition by double | |
40 | * checking that the first and the last byte of the image are covered by the | |
41 | * same EFI memory map entry. | |
42 | */ | |
43 | static bool check_image_region(u64 base, u64 size) | |
44 | { | |
45 | unsigned long map_size, desc_size, buff_size; | |
46 | efi_memory_desc_t *memory_map; | |
47 | struct efi_boot_memmap map; | |
48 | efi_status_t status; | |
49 | bool ret = false; | |
50 | int map_offset; | |
51 | ||
52 | map.map = &memory_map; | |
53 | map.map_size = &map_size; | |
54 | map.desc_size = &desc_size; | |
55 | map.desc_ver = NULL; | |
56 | map.key_ptr = NULL; | |
57 | map.buff_size = &buff_size; | |
58 | ||
59 | status = efi_get_memory_map(&map); | |
60 | if (status != EFI_SUCCESS) | |
61 | return false; | |
62 | ||
63 | for (map_offset = 0; map_offset < map_size; map_offset += desc_size) { | |
64 | efi_memory_desc_t *md = (void *)memory_map + map_offset; | |
65 | u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE; | |
66 | ||
67 | /* | |
68 | * Find the region that covers base, and return whether | |
69 | * it covers base+size bytes. | |
70 | */ | |
71 | if (base >= md->phys_addr && base < end) { | |
72 | ret = (base + size) <= end; | |
73 | break; | |
74 | } | |
75 | } | |
76 | ||
77 | efi_bs_call(free_pool, memory_map); | |
78 | ||
79 | return ret; | |
80 | } | |
81 | ||
cd33a5c1 | 82 | efi_status_t handle_kernel_image(unsigned long *image_addr, |
dae31fd2 AB |
83 | unsigned long *image_size, |
84 | unsigned long *reserve_addr, | |
85 | unsigned long *reserve_size, | |
dae31fd2 | 86 | efi_loaded_image_t *image) |
3c7f2550 MS |
87 | { |
88 | efi_status_t status; | |
89 | unsigned long kernel_size, kernel_memsize = 0; | |
5d12da9d | 90 | u32 phys_seed = 0; |
2b5fe07a | 91 | |
3a262423 AB |
92 | /* |
93 | * Although relocatable kernels can fix up the misalignment with | |
94 | * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are | |
95 | * subtly out of sync with those recorded in the vmlinux when kaslr is | |
96 | * disabled but the image required relocation anyway. Therefore retain | |
97 | * 2M alignment if KASLR was explicitly disabled, even if it was not | |
98 | * going to be activated to begin with. | |
99 | */ | |
100 | u64 min_kimg_align = efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN; | |
101 | ||
2b5fe07a | 102 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
980771f6 | 103 | if (!efi_nokaslr) { |
cd33a5c1 | 104 | status = efi_get_random_bytes(sizeof(phys_seed), |
2b5fe07a AB |
105 | (u8 *)&phys_seed); |
106 | if (status == EFI_NOT_FOUND) { | |
1c761ee9 | 107 | efi_info("EFI_RNG_PROTOCOL unavailable\n"); |
d32de913 | 108 | efi_nokaslr = true; |
2b5fe07a | 109 | } else if (status != EFI_SUCCESS) { |
1c761ee9 | 110 | efi_err("efi_get_random_bytes() failed (0x%lx)\n", |
d32de913 AB |
111 | status); |
112 | efi_nokaslr = true; | |
2b5fe07a AB |
113 | } |
114 | } else { | |
793473c2 | 115 | efi_info("KASLR disabled on kernel command line\n"); |
2b5fe07a AB |
116 | } |
117 | } | |
73effccb | 118 | |
82046702 | 119 | if (image->image_base != _text) |
793473c2 | 120 | efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); |
3c7f2550 | 121 | |
634a9177 MC |
122 | if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN)) |
123 | efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n", | |
124 | SEGMENT_ALIGN >> 10); | |
c32ac11d | 125 | |
3c7f2550 | 126 | kernel_size = _edata - _text; |
2b5fe07a | 127 | kernel_memsize = kernel_size + (_end - _edata); |
120dc60d | 128 | *reserve_size = kernel_memsize; |
2b5fe07a AB |
129 | |
130 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { | |
131 | /* | |
132 | * If KASLR is enabled, and we have some randomness available, | |
133 | * locate the kernel at a randomized offset in physical memory. | |
134 | */ | |
3a262423 | 135 | status = efi_random_alloc(*reserve_size, min_kimg_align, |
5d12da9d | 136 | reserve_addr, phys_seed); |
ff80ef5b AB |
137 | if (status != EFI_SUCCESS) |
138 | efi_warn("efi_random_alloc() failed: 0x%lx\n", status); | |
2b5fe07a | 139 | } else { |
82046702 | 140 | status = EFI_OUT_OF_RESOURCES; |
2b5fe07a | 141 | } |
e38457c3 | 142 | |
2b5fe07a | 143 | if (status != EFI_SUCCESS) { |
5b94046e AB |
144 | if (!check_image_region((u64)_text, kernel_memsize)) { |
145 | efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n"); | |
3a262423 | 146 | } else if (IS_ALIGNED((u64)_text, min_kimg_align)) { |
82046702 AB |
147 | /* |
148 | * Just execute from wherever we were loaded by the | |
149 | * UEFI PE/COFF loader if the alignment is suitable. | |
150 | */ | |
151 | *image_addr = (u64)_text; | |
152 | *reserve_size = 0; | |
153 | return EFI_SUCCESS; | |
154 | } | |
155 | ||
e71356fe | 156 | status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, |
3a262423 | 157 | ULONG_MAX, min_kimg_align); |
2b5fe07a AB |
158 | |
159 | if (status != EFI_SUCCESS) { | |
793473c2 | 160 | efi_err("Failed to relocate kernel\n"); |
2b5fe07a AB |
161 | *reserve_size = 0; |
162 | return status; | |
3c7f2550 | 163 | } |
3c7f2550 | 164 | } |
c2136dce | 165 | |
120dc60d | 166 | *image_addr = *reserve_addr; |
c2136dce | 167 | memcpy((void *)*image_addr, _text, kernel_size); |
3c7f2550 MS |
168 | |
169 | return EFI_SUCCESS; | |
170 | } |