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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#include <linux/efi.h>
13#include <asm/efi.h>
14#include <asm/sections.h>
15#include <asm/sysreg.h>
16
17#include "efistub.h"
18
19extern bool __nokaslr;
20
21efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
22{
23 u64 tg;
24
25 /* UEFI mandates support for 4 KB granularity, no need to check */
26 if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
27 return EFI_SUCCESS;
28
29 tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
30 if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
31 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
32 pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n");
33 else
34 pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n");
35 return EFI_UNSUPPORTED;
36 }
37 return EFI_SUCCESS;
38}
39
40efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
41 unsigned long *image_addr,
42 unsigned long *image_size,
43 unsigned long *reserve_addr,
44 unsigned long *reserve_size,
45 unsigned long dram_base,
46 efi_loaded_image_t *image)
47{
48 efi_status_t status;
49 unsigned long kernel_size, kernel_memsize = 0;
50 void *old_image_addr = (void *)*image_addr;
51 unsigned long preferred_offset;
52 u64 phys_seed = 0;
53
54 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
55 if (!__nokaslr) {
56 status = efi_get_random_bytes(sys_table_arg,
57 sizeof(phys_seed),
58 (u8 *)&phys_seed);
59 if (status == EFI_NOT_FOUND) {
60 pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n");
61 } else if (status != EFI_SUCCESS) {
62 pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n");
63 return status;
64 }
65 } else {
66 pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n");
67 }
68 }
69
70 /*
71 * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
72 * a 2 MB aligned base, which itself may be lower than dram_base, as
73 * long as the resulting offset equals or exceeds it.
74 */
75 preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET;
76 if (preferred_offset < dram_base)
77 preferred_offset += MIN_KIMG_ALIGN;
78
79 kernel_size = _edata - _text;
80 kernel_memsize = kernel_size + (_end - _edata);
81
82 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
83 /*
84 * If KASLR is enabled, and we have some randomness available,
85 * locate the kernel at a randomized offset in physical memory.
86 */
87 *reserve_size = kernel_memsize + TEXT_OFFSET;
88 status = efi_random_alloc(sys_table_arg, *reserve_size,
89 MIN_KIMG_ALIGN, reserve_addr,
90 phys_seed);
91
92 *image_addr = *reserve_addr + TEXT_OFFSET;
93 } else {
94 /*
95 * Else, try a straight allocation at the preferred offset.
96 * This will work around the issue where, if dram_base == 0x0,
97 * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
98 * address of the allocation to be mistaken for a FAIL return
99 * value or a NULL pointer). It will also ensure that, on
100 * platforms where the [dram_base, dram_base + TEXT_OFFSET)
101 * interval is partially occupied by the firmware (like on APM
102 * Mustang), we can still place the kernel at the address
103 * 'dram_base + TEXT_OFFSET'.
104 */
105 if (*image_addr == preferred_offset)
106 return EFI_SUCCESS;
107
108 *image_addr = *reserve_addr = preferred_offset;
109 *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN);
110
111 status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
112 EFI_LOADER_DATA,
113 *reserve_size / EFI_PAGE_SIZE,
114 (efi_physical_addr_t *)reserve_addr);
115 }
116
117 if (status != EFI_SUCCESS) {
118 *reserve_size = kernel_memsize + TEXT_OFFSET;
119 status = efi_low_alloc(sys_table_arg, *reserve_size,
120 MIN_KIMG_ALIGN, reserve_addr);
121
122 if (status != EFI_SUCCESS) {
123 pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
124 *reserve_size = 0;
125 return status;
126 }
127 *image_addr = *reserve_addr + TEXT_OFFSET;
128 }
129 memcpy((void *)*image_addr, old_image_addr, kernel_size);
130
131 return EFI_SUCCESS;
132}