1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Bootmethod for extlinux boot from a block device
4  *
5  * Copyright 2021 Google LLC
6  * Written by Simon Glass <sjg@chromium.org>
7  */
8 
9 #define LOG_CATEGORY UCLASS_BOOTSTD
10 
11 #include <asm/cache.h>
12 #include <bootdev.h>
13 #include <bootflow.h>
14 #include <bootmeth.h>
15 #include <bootstd.h>
16 #include <command.h>
17 #include <dm.h>
18 #include <extlinux.h>
19 #include <fs.h>
20 #include <malloc.h>
21 #include <mapmem.h>
22 #include <mmc.h>
23 #include <pxe_utils.h>
24 
25 struct extlinux_plat {
26 	bool use_fallback;
27 };
28 
29 enum extlinux_option_type {
30 	EO_FALLBACK,
31 	EO_INVALID
32 };
33 
34 struct extlinux_option {
35 	char *name;
36 	enum extlinux_option_type option;
37 };
38 
39 static const struct extlinux_option options[] = {
40 	{"fallback", EO_FALLBACK},
41 	{NULL, EO_INVALID}
42 };
43 
get_option(const char * option)44 static enum extlinux_option_type get_option(const char *option)
45 {
46 	int i = 0;
47 
48 	while (options[i].name) {
49 		if (!strcmp(options[i].name, option))
50 			return options[i].option;
51 
52 		i++;
53 	}
54 
55 	return EO_INVALID;
56 };
57 
extlinux_get_state_desc(struct udevice * dev,char * buf,int maxsize)58 static int extlinux_get_state_desc(struct udevice *dev, char *buf, int maxsize)
59 {
60 	if (IS_ENABLED(CONFIG_SANDBOX)) {
61 		int len;
62 
63 		len = snprintf(buf, maxsize, "OK");
64 
65 		return len + 1 < maxsize ? 0 : -ENOSPC;
66 	}
67 
68 	return 0;
69 }
70 
extlinux_getfile(struct pxe_context * ctx,const char * file_path,char * file_addr,enum bootflow_img_t type,ulong * sizep)71 static int extlinux_getfile(struct pxe_context *ctx, const char *file_path,
72 			    char *file_addr, enum bootflow_img_t type,
73 			    ulong *sizep)
74 {
75 	struct extlinux_info *info = ctx->userdata;
76 	ulong addr;
77 	int ret;
78 
79 	addr = simple_strtoul(file_addr, NULL, 16);
80 
81 	/* Allow up to 1GB */
82 	*sizep = 1 << 30;
83 	ret = bootmeth_read_file(info->dev, info->bflow, file_path, addr,
84 				 type, sizep);
85 	if (ret)
86 		return log_msg_ret("read", ret);
87 
88 	return 0;
89 }
90 
extlinux_check(struct udevice * dev,struct bootflow_iter * iter)91 static int extlinux_check(struct udevice *dev, struct bootflow_iter *iter)
92 {
93 	int ret;
94 
95 	/* This only works on block devices */
96 	ret = bootflow_iter_check_blk(iter);
97 	if (ret)
98 		return log_msg_ret("blk", ret);
99 
100 	return 0;
101 }
102 
103 /**
104  * extlinux_fill_info() - Decode the extlinux file to find out its info
105  *
106  * @bflow: Bootflow to process
107  * @return 0 if OK, -ve on error
108  */
extlinux_fill_info(struct bootflow * bflow)109 static int extlinux_fill_info(struct bootflow *bflow)
110 {
111 	struct membuf mb;
112 	char line[200];
113 	char *data;
114 	int len;
115 
116 	log_debug("parsing bflow file size %x\n", bflow->size);
117 	membuf_init(&mb, bflow->buf, bflow->size);
118 	membuf_putraw(&mb, bflow->size, true, &data);
119 	while (len = membuf_readline(&mb, line, sizeof(line) - 1, ' ', true), len) {
120 		char *tok, *p = line;
121 
122 		tok = strsep(&p, " ");
123 		if (p) {
124 			if (!strcmp("label", tok)) {
125 				bflow->os_name = strdup(p);
126 				if (!bflow->os_name)
127 					return log_msg_ret("os", -ENOMEM);
128 			}
129 		}
130 	}
131 
132 	return 0;
133 }
134 
extlinux_read_bootflow(struct udevice * dev,struct bootflow * bflow)135 static int extlinux_read_bootflow(struct udevice *dev, struct bootflow *bflow)
136 {
137 	struct blk_desc *desc;
138 	const char *const *prefixes;
139 	struct udevice *bootstd;
140 	const char *prefix;
141 	loff_t size;
142 	int ret, i;
143 
144 	ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
145 	if (ret)
146 		return log_msg_ret("std", ret);
147 
148 	/* If a block device, we require a partition table */
149 	if (bflow->blk && !bflow->part)
150 		return -ENOENT;
151 
152 	prefixes = bootstd_get_prefixes(bootstd);
153 	i = 0;
154 	desc = bflow->blk ? dev_get_uclass_plat(bflow->blk) : NULL;
155 	do {
156 		prefix = prefixes ? prefixes[i] : NULL;
157 
158 		ret = bootmeth_try_file(bflow, desc, prefix, EXTLINUX_FNAME);
159 	} while (ret && prefixes && prefixes[++i]);
160 	if (ret)
161 		return log_msg_ret("try", ret);
162 	size = bflow->size;
163 
164 	ret = bootmeth_alloc_file(bflow, 0x10000, ARCH_DMA_MINALIGN,
165 				  BFI_EXTLINUX_CFG);
166 	if (ret)
167 		return log_msg_ret("read", ret);
168 
169 	ret = extlinux_fill_info(bflow);
170 	if (ret)
171 		return log_msg_ret("inf", ret);
172 
173 	return 0;
174 }
175 
extlinux_boot(struct udevice * dev,struct bootflow * bflow)176 static int extlinux_boot(struct udevice *dev, struct bootflow *bflow)
177 {
178 	struct cmd_tbl cmdtp = {};	/* dummy */
179 	struct pxe_context ctx;
180 	struct extlinux_info info;
181 	struct extlinux_plat *plat;
182 	ulong addr;
183 	int ret;
184 
185 	addr = map_to_sysmem(bflow->buf);
186 	info.dev = dev;
187 	info.bflow = bflow;
188 
189 	plat = dev_get_plat(dev);
190 
191 	ret = pxe_setup_ctx(&ctx, &cmdtp, extlinux_getfile, &info, true,
192 			    bflow->fname, false, plat->use_fallback);
193 	if (ret)
194 		return log_msg_ret("ctx", -EINVAL);
195 
196 	ret = pxe_process(&ctx, addr, false);
197 	if (ret)
198 		return log_msg_ret("bread", -EINVAL);
199 
200 	return 0;
201 }
202 
extlinux_set_property(struct udevice * dev,const char * property,const char * value)203 static int extlinux_set_property(struct udevice *dev, const char *property, const char *value)
204 {
205 	struct extlinux_plat *plat;
206 	static enum extlinux_option_type option;
207 
208 	plat = dev_get_plat(dev);
209 
210 	option = get_option(property);
211 	if (option == EO_INVALID) {
212 		printf("Invalid option\n");
213 		return -EINVAL;
214 	}
215 
216 	switch (option) {
217 	case EO_FALLBACK:
218 		if (!strcmp(value, "1")) {
219 			plat->use_fallback = true;
220 		} else if (!strcmp(value, "0")) {
221 			plat->use_fallback = false;
222 		} else {
223 			printf("Unexpected value '%s'\n", value);
224 			return -EINVAL;
225 		}
226 		break;
227 	default:
228 		printf("Unrecognised property '%s'\n", property);
229 		return -EINVAL;
230 	}
231 
232 	return 0;
233 }
234 
extlinux_bootmeth_bind(struct udevice * dev)235 static int extlinux_bootmeth_bind(struct udevice *dev)
236 {
237 	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
238 
239 	plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
240 		"Extlinux boot from a block device" : "extlinux";
241 
242 	return 0;
243 }
244 
245 static struct bootmeth_ops extlinux_bootmeth_ops = {
246 	.get_state_desc	= extlinux_get_state_desc,
247 	.check		= extlinux_check,
248 	.read_bootflow	= extlinux_read_bootflow,
249 	.read_file	= bootmeth_common_read_file,
250 	.boot		= extlinux_boot,
251 	.set_property	= extlinux_set_property,
252 };
253 
254 static const struct udevice_id extlinux_bootmeth_ids[] = {
255 	{ .compatible = "u-boot,extlinux" },
256 	{ }
257 };
258 
259 /* Put a number before 'extlinux' to provide a default ordering */
260 U_BOOT_DRIVER(bootmeth_1extlinux) = {
261 	.name		= "bootmeth_extlinux",
262 	.id		= UCLASS_BOOTMETH,
263 	.of_match	= extlinux_bootmeth_ids,
264 	.ops		= &extlinux_bootmeth_ops,
265 	.bind		= extlinux_bootmeth_bind,
266 	.plat_auto	= sizeof(struct extlinux_plat)
267 };
268