1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2012 Samsung Electronics
15 #define CHECKSUM_OFFSET (14*1024-4)
16 #define FILE_PERM (S_IRUSR | S_IWUSR | S_IRGRP \
17 | S_IWGRP | S_IROTH | S_IWOTH)
19 * Requirement for the fixed size SPL header:
20 * IROM code reads first (CHECKSUM_OFFSET + 4) bytes from boot device. It then
21 * calculates the checksum of CHECKSUM_OFFSET bytes and compares with data at
22 * CHECKSUM_OFFSET location.
24 * Requirement for the variable size SPL header:
26 * IROM code reads the below header to find out the size of the blob (total
27 * size, header size included) and its checksum. Then it reads the rest of the
28 * blob [i.e size - sizeof(struct var_size_header) bytes], calculates the
29 * checksum and compares it with value read from the header.
31 struct var_size_header
{
33 uint32_t spl_checksum
;
37 static const char *prog_name
;
39 static void write_to_file(int ofd
, void *buffer
, int size
)
41 if (write(ofd
, buffer
, size
) == size
)
44 fprintf(stderr
, "%s: Failed to write to output file: %s\n",
45 prog_name
, strerror(errno
));
50 * The argv is expected to include one optional parameter and two filenames:
53 * --vs - turns on the variable size SPL mode
54 * IN - the u-boot SPL binary, usually u-boot-spl.bin
55 * OUT - the prepared SPL blob, usually ${BOARD}-spl.bin
57 * This utility first reads the "u-boot-spl.bin" into a buffer. In case of
58 * fixed size SPL the buffer size is exactly CHECKSUM_OFFSET (such that
59 * smaller u-boot-spl.bin gets padded with 0xff bytes, the larger than limit
60 * u-boot-spl.bin causes an error). For variable size SPL the buffer size is
61 * eqaul to size of the IN file.
63 * Then it calculates checksum of the buffer by just summing up all bytes.
66 * - for fixed size SPL the buffer is written into the output file and the
67 * checksum is appended to the file in little endian format, which results
68 * in checksum added exactly at CHECKSUM_OFFSET.
70 * - for variable size SPL the checksum and file size are stored in the
71 * var_size_header structure (again, in little endian format) and the
72 * structure is written into the output file. Then the buffer is written
73 * into the output file.
75 int main(int argc
, char **argv
)
77 unsigned char *buffer
;
79 uint32_t checksum
= 0;
81 int var_size_flag
, read_size
, count
;
83 const int if_index
= argc
- 2; /* Input file name index in argv. */
84 const int of_index
= argc
- 1; /* Output file name index in argv. */
86 /* Strip path off the program name. */
87 prog_name
= strrchr(argv
[0], '/');
95 ((argc
== 4) && strcmp(argv
[1], "--vs"))) {
96 fprintf(stderr
, "Usage: %s [--vs] <infile> <outfile>\n",
101 /* four args mean variable size SPL wrapper is required */
102 var_size_flag
= (argc
== 4);
104 ifd
= open(argv
[if_index
], O_RDONLY
);
106 fprintf(stderr
, "%s: Can't open %s: %s\n",
107 prog_name
, argv
[if_index
], strerror(errno
));
111 ofd
= open(argv
[of_index
], O_WRONLY
| O_CREAT
| O_TRUNC
, FILE_PERM
);
113 fprintf(stderr
, "%s: Can't open %s: %s\n",
114 prog_name
, argv
[of_index
], strerror(errno
));
118 if (fstat(ifd
, &stat
)) {
119 fprintf(stderr
, "%s: Unable to get size of %s: %s\n",
120 prog_name
, argv
[if_index
], strerror(errno
));
130 if (len
> CHECKSUM_OFFSET
) {
132 "%s: %s is too big (exceeds %d bytes)\n",
133 prog_name
, argv
[if_index
], CHECKSUM_OFFSET
);
136 count
= CHECKSUM_OFFSET
;
140 buffer
= malloc(count
);
143 "%s: Failed to allocate %d bytes to store %s\n",
144 prog_name
, count
, argv
[if_index
]);
148 if (read(ifd
, buffer
, read_size
) != read_size
) {
149 fprintf(stderr
, "%s: Can't read %s: %s\n",
150 prog_name
, argv
[if_index
], strerror(errno
));
154 /* Pad if needed with 0xff to make flashing faster. */
155 if (read_size
< count
)
156 memset((char *)buffer
+ read_size
, 0xff, count
- read_size
);
158 for (i
= 0, checksum
= 0; i
< count
; i
++)
159 checksum
+= buffer
[i
];
160 checksum
= cpu_to_le32(checksum
);
163 /* Prepare and write out the variable size SPL header. */
164 struct var_size_header vsh
;
167 memset(&vsh
, 0, sizeof(vsh
));
168 memcpy(&vsh
.spl_checksum
, &checksum
, sizeof(checksum
));
170 spl_size
= cpu_to_le32(count
+ sizeof(struct var_size_header
));
171 memcpy(&vsh
.spl_size
, &spl_size
, sizeof(spl_size
));
172 write_to_file(ofd
, &vsh
, sizeof(vsh
));
175 write_to_file(ofd
, buffer
, count
);
177 /* For fixed size SPL checksum is appended in the end. */
179 write_to_file(ofd
, &checksum
, sizeof(checksum
));