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