diff options
| -rw-r--r-- | mkubootenv.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/mkubootenv.c b/mkubootenv.c index 7c9922c..156e12d 100644 --- a/mkubootenv.c +++ b/mkubootenv.c @@ -1,4 +1,19 @@ /* + * mkubootenv.c + * + * Create a U-Boot environment image suitable for flashing. + * + * The input is a text file containing environment variable + * definitions in the following format (variables separated by + * newline): + * + * baudrate=115200 + * bootdelay=5 + * ethaddr=00:15:12:00:00:01 + * kernel_addr=4050000 + * boot_ram=bootm ${kernel_addr} + * bootcmd=run boot_ram + * * Copyright (c) 2009, Zurich University of Applied Science * Copyright (c) 2009, Tobias Klauser <klto@zhaw.ch> * @@ -131,7 +146,8 @@ int main(int argc, char **argv) * var=value\n */ - /* check whether the size hasn't been set or whether the source file + + /* + * check whether the size hasn't been set or whether the source file + * CRC + trailer fits into the specified size. */ min_img_size = CRC32_SIZE + s.sbuf.st_size + TRAILER_SIZE; @@ -151,7 +167,10 @@ int main(int argc, char **argv) goto err_out_munmap_s; } - /* seek to the end of the target file to write a byte */ + /* + * seek to the end of the target file to write a byte, so we have the + * whole target image size mapped for writing + */ if (lseek(t.fd, img_size - 1, SEEK_SET) < 0) { err("Can't seek in target image file '%s': %s\n", t.name, strerror(errno)); @@ -176,17 +195,14 @@ int main(int argc, char **argv) dbg("size: %zd\n", img_size); /* CRC32 placeholder, will be filled later */ - dbg("writing crc...\n"); + dbg("writing crc dummy...\n"); for (p = t.ptr; p < t.ptr + CRC32_SIZE; p++) *p = 0; /* copy the source file, replacing \n by \0 */ dbg("writing data...\n"); - for (q = s.ptr; q < s.ptr + s.sbuf.st_size; q++, p++) { - uint8_t c = (*q == '\n') ? '\0' : *q; - - *p = c; - } + for (q = s.ptr; q < s.ptr + s.sbuf.st_size; q++, p++) + *p = (*q == '\n') ? '\0' : *q; /* trailer */ dbg("writing trailer...\n"); |