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