diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/mkexynosspl.c | 167 |
1 files changed, 124 insertions, 43 deletions
diff --git a/tools/mkexynosspl.c b/tools/mkexynosspl.c index ef685b7..32b786c 100644 --- a/tools/mkexynosspl.c +++ b/tools/mkexynosspl.c @@ -14,93 +14,174 @@ #include <compiler.h> #define CHECKSUM_OFFSET (14*1024-4) -#define BUFSIZE (14*1024) #define FILE_PERM (S_IRUSR | S_IWUSR | S_IRGRP \ | S_IWGRP | S_IROTH | S_IWOTH) /* -* Requirement: -* IROM code reads first 14K bytes from boot device. -* It then calculates the checksum of 14K-4 bytes and compare with data at -* 14K-4 offset. -* -* This function takes two filenames: -* IN "u-boot-spl.bin" and -* OUT "$(BOARD)-spl.bin as filenames. -* It reads the "u-boot-spl.bin" in 16K buffer. -* It calculates checksum of 14K-4 Bytes and stores at 14K-4 offset in buffer. -* It writes the buffer to "$(BOARD)-spl.bin" file. -*/ + * Requirement for the fixed size SPL header: + * IROM code reads first (CHECKSUM_OFFSET + 4) bytes from boot device. It then + * calculates the checksum of CHECKSUM_OFFSET bytes and compares with data at + * CHECKSUM_OFFSET location. + * + * Requirement for the variable size SPL header: + + * IROM code reads the below header to find out the size of the blob (total + * size, header size included) and its checksum. Then it reads the rest of the + * blob [i.e size - sizeof(struct var_size_header) bytes], calculates the + * checksum and compares it with value read from the header. + */ +struct var_size_header { + uint32_t spl_size; + uint32_t spl_checksum; + uint32_t reserved[2]; +}; + +static const char *prog_name; + +static void write_to_file(int ofd, void *buffer, int size) +{ + if (write(ofd, buffer, size) == size) + return; + + fprintf(stderr, "%s: Failed to write to output file: %s\n", + prog_name, strerror(errno)); + exit(EXIT_FAILURE); +} +/* + * The argv is expected to include one optional parameter and two filenames: + * [--vs] IN OUT + * + * --vs - turns on the variable size SPL mode + * IN - the u-boot SPL binary, usually u-boot-spl.bin + * OUT - the prepared SPL blob, usually ${BOARD}-spl.bin + * + * This utility first reads the "u-boot-spl.bin" into a buffer. In case of + * fixed size SPL the buffer size is exactly CHECKSUM_OFFSET (such that + * smaller u-boot-spl.bin gets padded with 0xff bytes, the larger than limit + * u-boot-spl.bin causes an error). For variable size SPL the buffer size is + * eqaul to size of the IN file. + * + * Then it calculates checksum of the buffer by just summing up all bytes. + * Then + * + * - for fixed size SPL the buffer is written into the output file and the + * checksum is appended to the file in little endian format, which results + * in checksum added exactly at CHECKSUM_OFFSET. + * + * - for variable size SPL the checksum and file size are stored in the + * var_size_header structure (again, in little endian format) and the + * structure is written into the output file. Then the buffer is written + * into the output file. + */ int main(int argc, char **argv) { - unsigned char buffer[BUFSIZE]; + unsigned char *buffer; int i, ifd, ofd; uint32_t checksum = 0; off_t len; - ssize_t count; + int var_size_flag, read_size, count; struct stat stat; - - if (argc != 3) { - fprintf(stderr, "Usage: %s <infile> <outfile>\n", argv[0]); + const int if_index = argc - 2; /* Input file name index in argv. */ + const int of_index = argc - 1; /* Output file name index in argv. */ + + /* Strip path off the program name. */ + prog_name = strrchr(argv[0], '/'); + if (prog_name) + prog_name++; + else + prog_name = argv[0]; + + if ((argc < 3) || + (argc > 4) || + ((argc == 4) && strcmp(argv[1], "--vs"))) { + fprintf(stderr, "Usage: %s [--vs] <infile> <outfile>\n", + prog_name); exit(EXIT_FAILURE); } - ifd = open(argv[1], O_RDONLY); + /* four args mean variable size SPL wrapper is required */ + var_size_flag = (argc == 4); + + ifd = open(argv[if_index], O_RDONLY); if (ifd < 0) { fprintf(stderr, "%s: Can't open %s: %s\n", - argv[0], argv[1], strerror(errno)); + prog_name, argv[if_index], strerror(errno)); exit(EXIT_FAILURE); } - ofd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, FILE_PERM); + ofd = open(argv[of_index], O_WRONLY | O_CREAT | O_TRUNC, FILE_PERM); if (ifd < 0) { fprintf(stderr, "%s: Can't open %s: %s\n", - argv[0], argv[2], strerror(errno)); - close(ifd); + prog_name, argv[of_index], strerror(errno)); exit(EXIT_FAILURE); } if (fstat(ifd, &stat)) { fprintf(stderr, "%s: Unable to get size of %s: %s\n", - argv[0], argv[1], strerror(errno)); - close(ifd); - close(ofd); + prog_name, argv[if_index], strerror(errno)); exit(EXIT_FAILURE); } len = stat.st_size; - count = (len < CHECKSUM_OFFSET) ? len : CHECKSUM_OFFSET; - - if (read(ifd, buffer, count) != count) { - fprintf(stderr, "%s: Can't read %s: %s\n", - argv[0], argv[1], strerror(errno)); + if (var_size_flag) { + read_size = len; + count = len; + } else { + if (len > CHECKSUM_OFFSET) { + fprintf(stderr, + "%s: %s is too big (exceeds %d bytes)\n", + prog_name, argv[if_index], CHECKSUM_OFFSET); + exit(EXIT_FAILURE); + } + count = CHECKSUM_OFFSET; + read_size = len; + } - close(ifd); - close(ofd); + buffer = malloc(count); + if (!buffer) { + fprintf(stderr, + "%s: Failed to allocate %d bytes to store %s\n", + prog_name, count, argv[if_index]); + exit(EXIT_FAILURE); + } + if (read(ifd, buffer, read_size) != read_size) { + fprintf(stderr, "%s: Can't read %s: %s\n", + prog_name, argv[if_index], strerror(errno)); exit(EXIT_FAILURE); } - for (i = 0, checksum = 0; i < CHECKSUM_OFFSET; i++) - checksum += buffer[i]; + /* Pad if needed with 0xff to make flashing faster. */ + if (read_size < count) + memset((char *)buffer + read_size, 0xff, count - read_size); + for (i = 0, checksum = 0; i < count; i++) + checksum += buffer[i]; checksum = cpu_to_le32(checksum); - memcpy(&buffer[CHECKSUM_OFFSET], &checksum, sizeof(checksum)); - - if (write(ofd, buffer, BUFSIZE) != BUFSIZE) { - fprintf(stderr, "%s: Can't write %s: %s\n", - argv[0], argv[2], strerror(errno)); + if (var_size_flag) { + /* Prepare and write out the variable size SPL header. */ + struct var_size_header vsh; + uint32_t spl_size; - close(ifd); - close(ofd); + memset(&vsh, 0, sizeof(vsh)); + memcpy(&vsh.spl_checksum, &checksum, sizeof(checksum)); - exit(EXIT_FAILURE); + spl_size = cpu_to_le32(count + sizeof(struct var_size_header)); + memcpy(&vsh.spl_size, &spl_size, sizeof(spl_size)); + write_to_file(ofd, &vsh, sizeof(vsh)); } + write_to_file(ofd, buffer, count); + + /* For fixed size SPL checksum is appended in the end. */ + if (!var_size_flag) + write_to_file(ofd, &checksum, sizeof(checksum)); + close(ifd); close(ofd); + free(buffer); return EXIT_SUCCESS; } |