xref: /linux/arch/riscv/kernel/kexec_image.c (revision 119b1e61a769aa98e68599f44721661a4d8c55f3)
1*809a11eeSSong Shuai // SPDX-License-Identifier: GPL-2.0
2*809a11eeSSong Shuai /*
3*809a11eeSSong Shuai  * RISC-V Kexec image loader
4*809a11eeSSong Shuai  *
5*809a11eeSSong Shuai  */
6*809a11eeSSong Shuai 
7*809a11eeSSong Shuai #define pr_fmt(fmt)	"kexec_file(Image): " fmt
8*809a11eeSSong Shuai 
9*809a11eeSSong Shuai #include <linux/err.h>
10*809a11eeSSong Shuai #include <linux/errno.h>
11*809a11eeSSong Shuai #include <linux/kernel.h>
12*809a11eeSSong Shuai #include <linux/kexec.h>
13*809a11eeSSong Shuai #include <linux/pe.h>
14*809a11eeSSong Shuai #include <linux/string.h>
15*809a11eeSSong Shuai #include <asm/byteorder.h>
16*809a11eeSSong Shuai #include <asm/image.h>
17*809a11eeSSong Shuai 
image_probe(const char * kernel_buf,unsigned long kernel_len)18*809a11eeSSong Shuai static int image_probe(const char *kernel_buf, unsigned long kernel_len)
19*809a11eeSSong Shuai {
20*809a11eeSSong Shuai 	const struct riscv_image_header *h = (const struct riscv_image_header *)kernel_buf;
21*809a11eeSSong Shuai 
22*809a11eeSSong Shuai 	if (!h || kernel_len < sizeof(*h))
23*809a11eeSSong Shuai 		return -EINVAL;
24*809a11eeSSong Shuai 
25*809a11eeSSong Shuai 	/* According to Documentation/riscv/boot-image-header.rst,
26*809a11eeSSong Shuai 	 * use "magic2" field to check when version >= 0.2.
27*809a11eeSSong Shuai 	 */
28*809a11eeSSong Shuai 
29*809a11eeSSong Shuai 	if (h->version >= RISCV_HEADER_VERSION &&
30*809a11eeSSong Shuai 	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
31*809a11eeSSong Shuai 		return -EINVAL;
32*809a11eeSSong Shuai 
33*809a11eeSSong Shuai 	return 0;
34*809a11eeSSong Shuai }
35*809a11eeSSong Shuai 
image_load(struct kimage * image,char * kernel,unsigned long kernel_len,char * initrd,unsigned long initrd_len,char * cmdline,unsigned long cmdline_len)36*809a11eeSSong Shuai static void *image_load(struct kimage *image,
37*809a11eeSSong Shuai 			char *kernel, unsigned long kernel_len,
38*809a11eeSSong Shuai 			char *initrd, unsigned long initrd_len,
39*809a11eeSSong Shuai 			char *cmdline, unsigned long cmdline_len)
40*809a11eeSSong Shuai {
41*809a11eeSSong Shuai 	struct riscv_image_header *h;
42*809a11eeSSong Shuai 	u64 flags;
43*809a11eeSSong Shuai 	bool be_image, be_kernel;
44*809a11eeSSong Shuai 	struct kexec_buf kbuf;
45*809a11eeSSong Shuai 	int ret;
46*809a11eeSSong Shuai 
47*809a11eeSSong Shuai 	/* Check Image header */
48*809a11eeSSong Shuai 	h = (struct riscv_image_header *)kernel;
49*809a11eeSSong Shuai 	if (!h->image_size) {
50*809a11eeSSong Shuai 		ret = -EINVAL;
51*809a11eeSSong Shuai 		goto out;
52*809a11eeSSong Shuai 	}
53*809a11eeSSong Shuai 
54*809a11eeSSong Shuai 	/* Check endianness */
55*809a11eeSSong Shuai 	flags = le64_to_cpu(h->flags);
56*809a11eeSSong Shuai 	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
57*809a11eeSSong Shuai 	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
58*809a11eeSSong Shuai 	if (be_image != be_kernel) {
59*809a11eeSSong Shuai 		ret = -EINVAL;
60*809a11eeSSong Shuai 		goto out;
61*809a11eeSSong Shuai 	}
62*809a11eeSSong Shuai 
63*809a11eeSSong Shuai 	/* Load the kernel image */
64*809a11eeSSong Shuai 	kbuf.image = image;
65*809a11eeSSong Shuai 	kbuf.buf_min = 0;
66*809a11eeSSong Shuai 	kbuf.buf_max = ULONG_MAX;
67*809a11eeSSong Shuai 	kbuf.top_down = false;
68*809a11eeSSong Shuai 
69*809a11eeSSong Shuai 	kbuf.buffer = kernel;
70*809a11eeSSong Shuai 	kbuf.bufsz = kernel_len;
71*809a11eeSSong Shuai 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
72*809a11eeSSong Shuai 	kbuf.memsz = le64_to_cpu(h->image_size);
73*809a11eeSSong Shuai 	kbuf.buf_align = le64_to_cpu(h->text_offset);
74*809a11eeSSong Shuai 
75*809a11eeSSong Shuai 	ret = kexec_add_buffer(&kbuf);
76*809a11eeSSong Shuai 	if (ret) {
77*809a11eeSSong Shuai 		pr_err("Error add kernel image ret=%d\n", ret);
78*809a11eeSSong Shuai 		goto out;
79*809a11eeSSong Shuai 	}
80*809a11eeSSong Shuai 
81*809a11eeSSong Shuai 	image->start = kbuf.mem;
82*809a11eeSSong Shuai 
83*809a11eeSSong Shuai 	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
84*809a11eeSSong Shuai 		kbuf.mem, kbuf.bufsz, kbuf.memsz);
85*809a11eeSSong Shuai 
86*809a11eeSSong Shuai 	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
87*809a11eeSSong Shuai 				  initrd, initrd_len, cmdline, cmdline_len);
88*809a11eeSSong Shuai 
89*809a11eeSSong Shuai out:
90*809a11eeSSong Shuai 	return ret ? ERR_PTR(ret) : NULL;
91*809a11eeSSong Shuai }
92*809a11eeSSong Shuai 
93*809a11eeSSong Shuai const struct kexec_file_ops image_kexec_ops = {
94*809a11eeSSong Shuai 	.probe = image_probe,
95*809a11eeSSong Shuai 	.load = image_load,
96*809a11eeSSong Shuai };
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