1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Compact binary representation of ihex records. Some devices need their |
4 | * firmware loaded in strange orders rather than a single big blob, but |
5 | * actually parsing ihex-as-text within the kernel seems silly. Thus,... |
6 | */ |
7 | |
8 | #ifndef __LINUX_IHEX_H__ |
9 | #define __LINUX_IHEX_H__ |
10 | |
11 | #include <linux/types.h> |
12 | #include <linux/firmware.h> |
13 | #include <linux/device.h> |
14 | |
15 | /* Intel HEX files actually limit the length to 256 bytes, but we have |
16 | drivers which would benefit from using separate records which are |
17 | longer than that, so we extend to 16 bits of length */ |
18 | struct ihex_binrec { |
19 | __be32 addr; |
20 | __be16 len; |
21 | uint8_t data[]; |
22 | } __attribute__((packed)); |
23 | |
24 | static inline uint16_t ihex_binrec_size(const struct ihex_binrec *p) |
25 | { |
26 | return be16_to_cpu(p->len) + sizeof(*p); |
27 | } |
28 | |
29 | /* Find the next record, taking into account the 4-byte alignment */ |
30 | static inline const struct ihex_binrec * |
31 | __ihex_next_binrec(const struct ihex_binrec *rec) |
32 | { |
33 | const void *p = rec; |
34 | |
35 | return p + ALIGN(ihex_binrec_size(rec), 4); |
36 | } |
37 | |
38 | static inline const struct ihex_binrec * |
39 | ihex_next_binrec(const struct ihex_binrec *rec) |
40 | { |
41 | rec = __ihex_next_binrec(rec); |
42 | |
43 | return be16_to_cpu(rec->len) ? rec : NULL; |
44 | } |
45 | |
46 | /* Check that ihex_next_binrec() won't take us off the end of the image... */ |
47 | static inline int ihex_validate_fw(const struct firmware *fw) |
48 | { |
49 | const struct ihex_binrec *end, *rec; |
50 | |
51 | rec = (const void *)fw->data; |
52 | end = (const void *)&fw->data[fw->size - sizeof(*end)]; |
53 | |
54 | for (; rec <= end; rec = __ihex_next_binrec(rec)) { |
55 | /* Zero length marks end of records */ |
56 | if (rec == end && !be16_to_cpu(rec->len)) |
57 | return 0; |
58 | } |
59 | return -EINVAL; |
60 | } |
61 | |
62 | /* Request firmware and validate it so that we can trust we won't |
63 | * run off the end while reading records... */ |
64 | static inline int request_ihex_firmware(const struct firmware **fw, |
65 | const char *fw_name, |
66 | struct device *dev) |
67 | { |
68 | const struct firmware *lfw; |
69 | int ret; |
70 | |
71 | ret = request_firmware(fw: &lfw, name: fw_name, device: dev); |
72 | if (ret) |
73 | return ret; |
74 | ret = ihex_validate_fw(fw: lfw); |
75 | if (ret) { |
76 | dev_err(dev, "Firmware \"%s\" not valid IHEX records\n" , |
77 | fw_name); |
78 | release_firmware(fw: lfw); |
79 | return ret; |
80 | } |
81 | *fw = lfw; |
82 | return 0; |
83 | } |
84 | #endif /* __LINUX_IHEX_H__ */ |
85 | |