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"Das U-Boot" Source Tree
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 <blk.h>
13#include <bootdev.h>
14#include <dm.h>
15#include <log.h>
16#include <malloc.h>
17#include <os.h>
18#include <sandbox_host.h>
19#include <dm/device-internal.h>
20
21static int host_sb_attach_file(struct udevice *dev, const char *filename)
22{
23 struct host_sb_plat *plat = dev_get_plat(dev);
24 struct blk_desc *desc;
25 struct udevice *blk;
26 int ret, fd;
27 off_t size;
28 char *fname;
29
30 if (!filename)
31 return -EINVAL;
32
33 if (plat->fd)
34 return log_msg_ret("fd", -EEXIST);
35
36 /* Sanity check that host_sb_bind() has been used */
37 ret = blk_find_from_parent(dev, &blk);
38 if (ret)
39 return ret;
40
41 fd = os_open(filename, OS_O_RDWR);
42 if (fd == -1) {
43 printf("Failed to access host backing file '%s', trying read-only\n",
44 filename);
45 fd = os_open(filename, OS_O_RDONLY);
46 if (fd == -1) {
47 printf("- still failed\n");
48 return log_msg_ret("open", -ENOENT);
49 }
50 }
51
52 fname = strdup(filename);
53 if (!fname) {
54 ret = -ENOMEM;
55 goto err_fname;
56 }
57
58 size = os_filesize(fd);
59 desc = dev_get_uclass_plat(blk);
60 if (size % desc->blksz) {
61 printf("The size of host backing file '%s' is not multiple of "
62 "the device block size\n", filename);
63 ret = -EINVAL;
64 goto err_fname;
65 }
66 desc->lba = size / desc->blksz;
67
68 /* write this in last, when nothing can go wrong */
69 plat = dev_get_plat(dev);
70 plat->fd = fd;
71 plat->filename = fname;
72
73 return 0;
74
75err_fname:
76 os_close(fd);
77
78 return ret;
79}
80
81static int host_sb_detach_file(struct udevice *dev)
82{
83 struct host_sb_plat *plat = dev_get_plat(dev);
84 int ret;
85
86 if (!plat->fd)
87 return log_msg_ret("fd", -ENOENT);
88
89 ret = device_remove(dev, DM_REMOVE_NORMAL);
90 if (ret)
91 return log_msg_ret("rem", ret);
92
93 /* Unbind all children */
94 ret = device_chld_unbind(dev, NULL);
95 if (ret)
96 return log_msg_ret("unb", ret);
97
98 os_close(plat->fd);
99 plat->fd = 0;
100 free(plat->filename);
101 free(plat->label);
102
103 return 0;
104}
105
106static int host_sb_bind(struct udevice *dev)
107{
108 struct udevice *blk, *bdev;
109 struct blk_desc *desc;
110 int ret;
111
112 ret = blk_create_devicef(dev, "sandbox_host_blk", "blk", UCLASS_HOST,
113 dev_seq(dev), DEFAULT_BLKSZ, 0, &blk);
114 if (ret)
115 return log_msg_ret("blk", ret);
116
117 desc = dev_get_uclass_plat(blk);
118 snprintf(desc->vendor, BLK_VEN_SIZE, "U-Boot");
119 snprintf(desc->product, BLK_PRD_SIZE, "hostfile");
120 snprintf(desc->revision, BLK_REV_SIZE, "1.0");
121
122 if (CONFIG_IS_ENABLED(BOOTSTD)) {
123 ret = bootdev_bind(dev, "host_bootdev", "bootdev", &bdev);
124 if (ret)
125 return log_msg_ret("bd", ret);
126 }
127
128 return 0;
129}
130
131static struct host_ops host_sb_ops = {
132 .attach_file = host_sb_attach_file,
133 .detach_file = host_sb_detach_file,
134};
135
136static const struct udevice_id host_ids[] = {
137 { .compatible = "sandbox,host" },
138 { }
139};
140
141U_BOOT_DRIVER(host_sb_drv) = {
142 .name = "host_sb_drv",
143 .id = UCLASS_HOST,
144 .of_match = host_ids,
145 .ops = &host_sb_ops,
146 .bind = host_sb_bind,
147 .plat_auto = sizeof(struct host_sb_plat),
148};