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1// SPDX-License-Identifier: GPL-2.0
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>
7 */
8
9
10#include <linux/efi.h>
11#include <asm/efi.h>
12#include <asm/memory.h>
13#include <asm/sections.h>
14
15#include "efistub.h"
16
17efi_status_t handle_kernel_image(unsigned long *image_addr,
18 unsigned long *image_size,
19 unsigned long *reserve_addr,
20 unsigned long *reserve_size,
21 efi_loaded_image_t *image,
22 efi_handle_t image_handle)
23{
24 efi_status_t status;
25 unsigned long kernel_size, kernel_codesize, kernel_memsize;
26
27 if (image->image_base != _text) {
28 efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
29 image->image_base = _text;
30 }
31
32 if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN))
33 efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n",
34 SEGMENT_ALIGN >> 10);
35
36 kernel_size = _edata - _text;
37 kernel_codesize = __inittext_end - _text;
38 kernel_memsize = kernel_size + (_end - _edata);
39 *reserve_size = kernel_memsize;
40 *image_addr = (unsigned long)_text;
41
42 status = efi_kaslr_relocate_kernel(image_addr,
43 reserve_addr, reserve_size,
44 kernel_size, kernel_codesize,
45 kernel_memsize,
46 efi_kaslr_get_phys_seed(image_handle));
47 if (status != EFI_SUCCESS)
48 return status;
49
50 return EFI_SUCCESS;
51}
52
53asmlinkage void primary_entry(void);
54
55unsigned long primary_entry_offset(void)
56{
57 /*
58 * When built as part of the kernel, the EFI stub cannot branch to the
59 * kernel proper via the image header, as the PE/COFF header is
60 * strictly not part of the in-memory presentation of the image, only
61 * of the file representation. So instead, we need to jump to the
62 * actual entrypoint in the .text region of the image.
63 */
64 return (char *)primary_entry - _text;
65}
66
67void efi_icache_sync(unsigned long start, unsigned long end)
68{
69 caches_clean_inval_pou(start, end);
70}
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 */
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
21#include <linux/efi.h>
22#include <asm/efi.h>
23#include <asm/memory.h>
24#include <asm/sysreg.h>
25
26#include "efistub.h"
27
28efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
29{
30 u64 tg;
31
32 /* UEFI mandates support for 4 KB granularity, no need to check */
33 if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
34 return EFI_SUCCESS;
35
36 tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
37 if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
38 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
39 pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n");
40 else
41 pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n");
42 return EFI_UNSUPPORTED;
43 }
44 return EFI_SUCCESS;
45}
46
47efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
48 unsigned long *image_addr,
49 unsigned long *image_size,
50 unsigned long *reserve_addr,
51 unsigned long *reserve_size,
52 unsigned long dram_base,
53 efi_loaded_image_t *image)
54{
55 efi_status_t status;
56 unsigned long kernel_size, kernel_memsize = 0;
57 void *old_image_addr = (void *)*image_addr;
58 unsigned long preferred_offset;
59 u64 phys_seed = 0;
60
61 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
62 if (!nokaslr()) {
63 status = efi_get_random_bytes(sys_table_arg,
64 sizeof(phys_seed),
65 (u8 *)&phys_seed);
66 if (status == EFI_NOT_FOUND) {
67 pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n");
68 } else if (status != EFI_SUCCESS) {
69 pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n");
70 return status;
71 }
72 } else {
73 pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n");
74 }
75 }
76
77 /*
78 * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
79 * a 2 MB aligned base, which itself may be lower than dram_base, as
80 * long as the resulting offset equals or exceeds it.
81 */
82 preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET;
83 if (preferred_offset < dram_base)
84 preferred_offset += MIN_KIMG_ALIGN;
85
86 kernel_size = _edata - _text;
87 kernel_memsize = kernel_size + (_end - _edata);
88
89 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
90 /*
91 * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a
92 * displacement in the interval [0, MIN_KIMG_ALIGN) that
93 * doesn't violate this kernel's de-facto alignment
94 * constraints.
95 */
96 u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1);
97 u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ?
98 (phys_seed >> 32) & mask : TEXT_OFFSET;
99
100 /*
101 * With CONFIG_RANDOMIZE_TEXT_OFFSET=y, TEXT_OFFSET may not
102 * be a multiple of EFI_KIMG_ALIGN, and we must ensure that
103 * we preserve the misalignment of 'offset' relative to
104 * EFI_KIMG_ALIGN so that statically allocated objects whose
105 * alignment exceeds PAGE_SIZE appear correctly aligned in
106 * memory.
107 */
108 offset |= TEXT_OFFSET % EFI_KIMG_ALIGN;
109
110 /*
111 * If KASLR is enabled, and we have some randomness available,
112 * locate the kernel at a randomized offset in physical memory.
113 */
114 *reserve_size = kernel_memsize + offset;
115 status = efi_random_alloc(sys_table_arg, *reserve_size,
116 MIN_KIMG_ALIGN, reserve_addr,
117 (u32)phys_seed);
118
119 *image_addr = *reserve_addr + offset;
120 } else {
121 /*
122 * Else, try a straight allocation at the preferred offset.
123 * This will work around the issue where, if dram_base == 0x0,
124 * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
125 * address of the allocation to be mistaken for a FAIL return
126 * value or a NULL pointer). It will also ensure that, on
127 * platforms where the [dram_base, dram_base + TEXT_OFFSET)
128 * interval is partially occupied by the firmware (like on APM
129 * Mustang), we can still place the kernel at the address
130 * 'dram_base + TEXT_OFFSET'.
131 */
132 if (*image_addr == preferred_offset)
133 return EFI_SUCCESS;
134
135 *image_addr = *reserve_addr = preferred_offset;
136 *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN);
137
138 status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
139 EFI_LOADER_DATA,
140 *reserve_size / EFI_PAGE_SIZE,
141 (efi_physical_addr_t *)reserve_addr);
142 }
143
144 if (status != EFI_SUCCESS) {
145 *reserve_size = kernel_memsize + TEXT_OFFSET;
146 status = efi_low_alloc(sys_table_arg, *reserve_size,
147 MIN_KIMG_ALIGN, reserve_addr);
148
149 if (status != EFI_SUCCESS) {
150 pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
151 *reserve_size = 0;
152 return status;
153 }
154 *image_addr = *reserve_addr + TEXT_OFFSET;
155 }
156 memcpy((void *)*image_addr, old_image_addr, kernel_size);
157
158 return EFI_SUCCESS;
159}