1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 2018 Linaro Limited
6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
8 * Most code is derived from arm64 port of kexec-tools
11 #define pr_fmt(fmt) "kexec_file: " fmt
13 #include <linux/ioport.h>
14 #include <linux/kernel.h>
15 #include <linux/kexec.h>
16 #include <linux/libfdt.h>
17 #include <linux/memblock.h>
18 #include <linux/of_fdt.h>
19 #include <linux/random.h>
20 #include <linux/string.h>
21 #include <linux/types.h>
22 #include <linux/vmalloc.h>
23 #include <asm/byteorder.h>
25 /* relevant device tree properties */
26 #define FDT_PROP_INITRD_START "linux,initrd-start"
27 #define FDT_PROP_INITRD_END "linux,initrd-end"
28 #define FDT_PROP_BOOTARGS "bootargs"
29 #define FDT_PROP_KASLR_SEED "kaslr-seed"
30 #define FDT_PROP_RNG_SEED "rng-seed"
31 #define RNG_SEED_SIZE 128
33 const struct kexec_file_ops * const kexec_file_loaders[] = {
38 int arch_kimage_file_post_load_cleanup(struct kimage *image)
40 vfree(image->arch.dtb);
41 image->arch.dtb = NULL;
43 return kexec_image_post_load_cleanup_default(image);
46 static int setup_dtb(struct kimage *image,
47 unsigned long initrd_load_addr, unsigned long initrd_len,
48 char *cmdline, void *dtb)
52 ret = fdt_path_offset(dtb, "/chosen");
60 ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline);
64 ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS);
65 if (ret && (ret != -FDT_ERR_NOTFOUND))
70 if (initrd_load_addr) {
71 ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START,
76 ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END,
77 initrd_load_addr + initrd_len);
81 ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START);
82 if (ret && (ret != -FDT_ERR_NOTFOUND))
85 ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END);
86 if (ret && (ret != -FDT_ERR_NOTFOUND))
91 ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED);
92 if (ret == -FDT_ERR_NOTFOUND)
97 if (rng_is_initialized()) {
98 u64 seed = get_random_u64();
99 ret = fdt_setprop_u64(dtb, off, FDT_PROP_KASLR_SEED, seed);
103 pr_notice("RNG is not initialised: omitting \"%s\" property\n",
104 FDT_PROP_KASLR_SEED);
108 if (rng_is_initialized()) {
109 u8 rng_seed[RNG_SEED_SIZE];
110 get_random_bytes(rng_seed, RNG_SEED_SIZE);
111 ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, rng_seed,
116 pr_notice("RNG is not initialised: omitting \"%s\" property\n",
122 return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
128 * More space needed so that we can add initrd, bootargs, kaslr-seed, and
131 #define DTB_EXTRA_SPACE 0x1000
133 static int create_dtb(struct kimage *image,
134 unsigned long initrd_load_addr, unsigned long initrd_len,
135 char *cmdline, void **dtb)
142 cmdline_len = cmdline ? strlen(cmdline) : 0;
143 buf_size = fdt_totalsize(initial_boot_params)
144 + cmdline_len + DTB_EXTRA_SPACE;
147 buf = vmalloc(buf_size);
151 /* duplicate a device tree blob */
152 ret = fdt_open_into(initial_boot_params, buf, buf_size);
158 ret = setup_dtb(image, initrd_load_addr, initrd_len,
162 if (ret == -ENOMEM) {
163 /* unlikely, but just in case */
164 buf_size += DTB_EXTRA_SPACE;
179 int load_other_segments(struct kimage *image,
180 unsigned long kernel_load_addr,
181 unsigned long kernel_size,
182 char *initrd, unsigned long initrd_len,
185 struct kexec_buf kbuf;
187 unsigned long initrd_load_addr = 0, dtb_len;
191 /* not allocate anything below the kernel */
192 kbuf.buf_min = kernel_load_addr + kernel_size;
196 kbuf.buffer = initrd;
197 kbuf.bufsz = initrd_len;
198 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
199 kbuf.memsz = initrd_len;
201 /* within 1GB-aligned window of up to 32GB in size */
202 kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
203 + (unsigned long)SZ_1G * 32;
204 kbuf.top_down = false;
206 ret = kexec_add_buffer(&kbuf);
209 initrd_load_addr = kbuf.mem;
211 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
212 initrd_load_addr, initrd_len, initrd_len);
216 ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb);
218 pr_err("Preparing for new dtb failed\n");
222 dtb_len = fdt_totalsize(dtb);
224 kbuf.bufsz = dtb_len;
225 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
226 kbuf.memsz = dtb_len;
227 /* not across 2MB boundary */
228 kbuf.buf_align = SZ_2M;
229 kbuf.buf_max = ULONG_MAX;
230 kbuf.top_down = true;
232 ret = kexec_add_buffer(&kbuf);
235 image->arch.dtb = dtb;
236 image->arch.dtb_mem = kbuf.mem;
238 pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
239 kbuf.mem, dtb_len, dtb_len);