1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Bootmethod for extlinux boot using PXE (network boot)
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 <bootdev.h>
12 #include <bootflow.h>
13 #include <bootmeth.h>
14 #include <command.h>
15 #include <dm.h>
16 #include <env.h>
17 #include <extlinux.h>
18 #include <fs.h>
19 #include <log.h>
20 #include <malloc.h>
21 #include <mapmem.h>
22 #include <mmc.h>
23 #include <net.h>
24 #include <pxe_utils.h>
25 
extlinux_pxe_getfile(struct pxe_context * ctx,const char * file_path,char * file_addr,enum bootflow_img_t type,ulong * sizep)26 static int extlinux_pxe_getfile(struct pxe_context *ctx, const char *file_path,
27 				char *file_addr, enum bootflow_img_t type,
28 				ulong *sizep)
29 {
30 	struct extlinux_info *info = ctx->userdata;
31 	ulong addr;
32 	int ret;
33 
34 	addr = simple_strtoul(file_addr, NULL, 16);
35 
36 	/* Allow up to 1GB */
37 	*sizep = 1 << 30;
38 	ret = bootmeth_read_file(info->dev, info->bflow, file_path, addr,
39 				 type, sizep);
40 	if (ret)
41 		return log_msg_ret("read", ret);
42 
43 	return 0;
44 }
45 
extlinux_pxe_check(struct udevice * dev,struct bootflow_iter * iter)46 static int extlinux_pxe_check(struct udevice *dev, struct bootflow_iter *iter)
47 {
48 	int ret;
49 
50 	/* This only works on network devices */
51 	ret = bootflow_iter_check_net(iter);
52 	if (ret)
53 		return log_msg_ret("net", ret);
54 
55 	if (iter->method_flags & BOOTFLOW_METHF_DHCP_ONLY)
56 		return log_msg_ret("dhcp", -ENOTSUPP);
57 
58 	return 0;
59 }
60 
extlinux_pxe_read_bootflow(struct udevice * dev,struct bootflow * bflow)61 static int extlinux_pxe_read_bootflow(struct udevice *dev,
62 				      struct bootflow *bflow)
63 {
64 	const char *addr_str;
65 	char fname[200];
66 	char *bootdir;
67 	ulong addr;
68 	ulong size;
69 	char *buf;
70 	int ret;
71 
72 	addr_str = env_get("pxefile_addr_r");
73 	if (!addr_str)
74 		return log_msg_ret("pxeb", -EPERM);
75 	addr = simple_strtoul(addr_str, NULL, 16);
76 
77 	ret = dhcp_run(addr, NULL, false);
78 	if (ret)
79 		return log_msg_ret("dhc", ret);
80 
81 	log_debug("calling pxe_get()\n");
82 	ret = pxe_get(addr, &bootdir, &size, false);
83 	log_debug("pxe_get() returned %d\n", ret);
84 	if (ret)
85 		return log_msg_ret("pxeb", ret);
86 	bflow->size = size;
87 
88 	/* Use the directory of the dhcp bootdir as our subdir, if provided */
89 	if (bootdir) {
90 		const char *last_slash;
91 		int path_len;
92 
93 		last_slash = strrchr(bootdir, '/');
94 		if (last_slash) {
95 			path_len = (last_slash - bootdir) + 1;
96 			bflow->subdir = malloc(path_len + 1);
97 			memcpy(bflow->subdir, bootdir, path_len);
98 			bflow->subdir[path_len] = '\0';
99 		}
100 	}
101 	snprintf(fname, sizeof(fname), "%s%s",
102 		 bflow->subdir ? bflow->subdir : "", EXTLINUX_FNAME);
103 
104 	bflow->fname = strdup(fname);
105 	if (!bflow->fname)
106 		return log_msg_ret("name", -ENOMEM);
107 
108 	bflow->state = BOOTFLOWST_READY;
109 
110 	/* Allocate the buffer, including the \0 byte added by get_pxe_file() */
111 	buf = malloc(size + 1);
112 	if (!buf)
113 		return log_msg_ret("buf", -ENOMEM);
114 	memcpy(buf, map_sysmem(addr, 0), size + 1);
115 	bflow->buf = buf;
116 
117 	return 0;
118 }
119 
extlinux_pxe_read_file(struct udevice * dev,struct bootflow * bflow,const char * file_path,ulong addr,enum bootflow_img_t type,ulong * sizep)120 static int extlinux_pxe_read_file(struct udevice *dev, struct bootflow *bflow,
121 				  const char *file_path, ulong addr,
122 				  enum bootflow_img_t type, ulong *sizep)
123 {
124 	char *tftp_argv[] = {"tftp", NULL, NULL, NULL};
125 	struct pxe_context *ctx = dev_get_priv(dev);
126 	char file_addr[17];
127 	ulong size;
128 	int ret;
129 
130 	sprintf(file_addr, "%lx", addr);
131 	tftp_argv[1] = file_addr;
132 	tftp_argv[2] = (void *)file_path;
133 
134 	if (do_tftpb(ctx->cmdtp, 0, 3, tftp_argv))
135 		return -ENOENT;
136 	ret = pxe_get_file_size(&size);
137 	if (ret)
138 		return log_msg_ret("tftp", ret);
139 	if (size > *sizep)
140 		return log_msg_ret("spc", -ENOSPC);
141 	*sizep = size;
142 
143 	if (!bootflow_img_add(bflow, file_path, type, addr, size))
144 		return log_msg_ret("pxi", -ENOMEM);
145 
146 	return 0;
147 }
148 
extlinux_pxe_boot(struct udevice * dev,struct bootflow * bflow)149 static int extlinux_pxe_boot(struct udevice *dev, struct bootflow *bflow)
150 {
151 	struct pxe_context *ctx = dev_get_priv(dev);
152 	struct cmd_tbl cmdtp = {};	/* dummy */
153 	struct extlinux_info info;
154 	ulong addr;
155 	int ret;
156 
157 	addr = map_to_sysmem(bflow->buf);
158 	info.dev = dev;
159 	info.bflow = bflow;
160 	info.cmdtp = &cmdtp;
161 	ret = pxe_setup_ctx(ctx, &cmdtp, extlinux_pxe_getfile, &info, false,
162 			    bflow->subdir, false, false);
163 	if (ret)
164 		return log_msg_ret("ctx", -EINVAL);
165 
166 	ret = pxe_process(ctx, addr, false);
167 	if (ret)
168 		return log_msg_ret("bread", -EINVAL);
169 
170 	return 0;
171 }
172 
extlinux_bootmeth_pxe_bind(struct udevice * dev)173 static int extlinux_bootmeth_pxe_bind(struct udevice *dev)
174 {
175 	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
176 
177 	plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
178 		"PXE boot from a network device" : "PXE";
179 
180 	return 0;
181 }
182 
183 static struct bootmeth_ops extlinux_bootmeth_pxe_ops = {
184 	.check		= extlinux_pxe_check,
185 	.read_bootflow	= extlinux_pxe_read_bootflow,
186 	.read_file	= extlinux_pxe_read_file,
187 	.boot		= extlinux_pxe_boot,
188 };
189 
190 static const struct udevice_id extlinux_bootmeth_pxe_ids[] = {
191 	{ .compatible = "u-boot,extlinux-pxe" },
192 	{ }
193 };
194 
195 U_BOOT_DRIVER(bootmeth_zpxe) = {
196 	.name		= "bootmeth_pxe",
197 	.id		= UCLASS_BOOTMETH,
198 	.of_match	= extlinux_bootmeth_pxe_ids,
199 	.ops		= &extlinux_bootmeth_pxe_ops,
200 	.bind		= extlinux_bootmeth_pxe_bind,
201 	.priv_auto	= sizeof(struct pxe_context),
202 };
203