1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for sandbox host interface, used to access files on the host which
4 * contain partitions and filesystem
5 *
6 * Copyright 2022 Google LLC
7 * Written by Simon Glass <sjg@chromium.org>
8 */
9
10 #define LOG_CATEGORY UCLASS_HOST
11
12 #include <common.h>
13 #include <blk.h>
14 #include <bootdev.h>
15 #include <dm.h>
16 #include <log.h>
17 #include <malloc.h>
18 #include <os.h>
19 #include <sandbox_host.h>
20 #include <dm/device-internal.h>
21
host_sb_attach_file(struct udevice * dev,const char * filename)22 static int host_sb_attach_file(struct udevice *dev, const char *filename)
23 {
24 struct host_sb_plat *plat = dev_get_plat(dev);
25 struct blk_desc *desc;
26 struct udevice *blk;
27 int ret, fd;
28 off_t size;
29 char *fname;
30
31 if (!filename)
32 return -EINVAL;
33
34 if (plat->fd)
35 return log_msg_ret("fd", -EEXIST);
36
37 /* Sanity check that host_sb_bind() has been used */
38 ret = blk_find_from_parent(dev, &blk);
39 if (ret)
40 return ret;
41
42 fd = os_open(filename, OS_O_RDWR);
43 if (fd == -1) {
44 printf("Failed to access host backing file '%s', trying read-only\n",
45 filename);
46 fd = os_open(filename, OS_O_RDONLY);
47 if (fd == -1) {
48 printf("- still failed\n");
49 return log_msg_ret("open", -ENOENT);
50 }
51 }
52
53 fname = strdup(filename);
54 if (!fname) {
55 ret = -ENOMEM;
56 goto err_fname;
57 }
58
59 size = os_filesize(fd);
60 desc = dev_get_uclass_plat(blk);
61 desc->lba = size / desc->blksz;
62
63 /* write this in last, when nothing can go wrong */
64 plat = dev_get_plat(dev);
65 plat->fd = fd;
66 plat->filename = fname;
67
68 return 0;
69
70 err_fname:
71 os_close(fd);
72
73 return ret;
74 }
75
host_sb_detach_file(struct udevice * dev)76 int host_sb_detach_file(struct udevice *dev)
77 {
78 struct host_sb_plat *plat = dev_get_plat(dev);
79 int ret;
80
81 if (!plat->fd)
82 return log_msg_ret("fd", -ENOENT);
83
84 ret = device_remove(dev, DM_REMOVE_NORMAL);
85 if (ret)
86 return log_msg_ret("rem", ret);
87
88 /* Unbind all children */
89 ret = device_chld_unbind(dev, NULL);
90 if (ret)
91 return log_msg_ret("unb", ret);
92
93 os_close(plat->fd);
94 plat->fd = 0;
95 free(plat->filename);
96 free(plat->label);
97
98 return 0;
99 }
100
host_sb_bind(struct udevice * dev)101 static int host_sb_bind(struct udevice *dev)
102 {
103 struct udevice *blk, *bdev;
104 struct blk_desc *desc;
105 int ret;
106
107 ret = blk_create_devicef(dev, "sandbox_host_blk", "blk", UCLASS_HOST,
108 dev_seq(dev), 512, 0, &blk);
109 if (ret)
110 return log_msg_ret("blk", ret);
111
112 desc = dev_get_uclass_plat(blk);
113 snprintf(desc->vendor, BLK_VEN_SIZE, "U-Boot");
114 snprintf(desc->product, BLK_PRD_SIZE, "hostfile");
115 snprintf(desc->revision, BLK_REV_SIZE, "1.0");
116
117 if (CONFIG_IS_ENABLED(BOOTSTD)) {
118 ret = bootdev_bind(dev, "host_bootdev", "bootdev", &bdev);
119 if (ret)
120 return log_msg_ret("bd", ret);
121 }
122
123 return 0;
124 }
125
126 struct host_ops host_sb_ops = {
127 .attach_file = host_sb_attach_file,
128 .detach_file = host_sb_detach_file,
129 };
130
131 static const struct udevice_id host_ids[] = {
132 { .compatible = "sandbox,host" },
133 { }
134 };
135
136 U_BOOT_DRIVER(host_sb_drv) = {
137 .name = "host_sb_drv",
138 .id = UCLASS_HOST,
139 .of_match = host_ids,
140 .ops = &host_sb_ops,
141 .bind = host_sb_bind,
142 .plat_auto = sizeof(struct host_sb_plat),
143 };
144