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-rw-r--r--tools/mkexynosspl.c167
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;
}