kexec_image.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * RISC-V Kexec image loader
 4 *
 5 */
 6
 7#define pr_fmt(fmt)	"kexec_file(Image): " fmt
 8
 9#include <linux/err.h>
10#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/kexec.h>
13#include <linux/pe.h>
14#include <linux/string.h>
15#include <asm/byteorder.h>
16#include <asm/image.h>
17
18static int image_probe(const char *kernel_buf, unsigned long kernel_len)
19{
20	const struct riscv_image_header *h = (const struct riscv_image_header *)kernel_buf;
21
22	if (!h || kernel_len < sizeof(*h))
23		return -EINVAL;
24
25	/* According to Documentation/arch/riscv/boot-image-header.rst,
26	 * use "magic2" field to check when version >= 0.2.
27	 */
28
29	if (h->version >= RISCV_HEADER_VERSION &&
30	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
31		return -EINVAL;
32
33	return 0;
34}
35
36static void *image_load(struct kimage *image,
37			char *kernel, unsigned long kernel_len,
38			char *initrd, unsigned long initrd_len,
39			char *cmdline, unsigned long cmdline_len)
40{
41	struct riscv_image_header *h;
42	u64 flags;
43	bool be_image, be_kernel;
44	struct kexec_buf kbuf = {};
45	int ret;
46
47	/* Check Image header */
48	h = (struct riscv_image_header *)kernel;
49	if (!h->image_size) {
50		ret = -EINVAL;
51		goto out;
52	}
53
54	/* Check endianness */
55	flags = le64_to_cpu(h->flags);
56	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
57	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
58	if (be_image != be_kernel) {
59		ret = -EINVAL;
60		goto out;
61	}
62
63	/* Load the kernel image */
64	kbuf.image = image;
65	kbuf.buf_min = 0;
66	kbuf.buf_max = ULONG_MAX;
67	kbuf.top_down = false;
68
69	kbuf.buffer = kernel;
70	kbuf.bufsz = kernel_len;
71	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
72	kbuf.memsz = le64_to_cpu(h->image_size);
73	kbuf.buf_align = le64_to_cpu(h->text_offset);
74
75	ret = kexec_add_buffer(&kbuf);
76	if (ret) {
77		pr_err("Error add kernel image ret=%d\n", ret);
78		goto out;
79	}
80
81	image->start = kbuf.mem;
82
83	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
84		kbuf.mem, kbuf.bufsz, kbuf.memsz);
85
86	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
87				  initrd, initrd_len, cmdline, cmdline_len);
88
89out:
90	return ret ? ERR_PTR(ret) : NULL;
91}
92
93const struct kexec_file_ops image_kexec_ops = {
94	.probe = image_probe,
95	.load = image_load,
96};