diff options
| -rw-r--r-- | util/nvmutil/nvmutil.c | 40 |
1 files changed, 26 insertions, 14 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 5b541179..be02961c 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -17,7 +17,8 @@ void cmd_setchecksum(void), cmd_brick(void), swap(int partnum), writeGbe(void), cmd_dump(void), cmd_setmac(void), readGbe(void), checkdir(const char *path), macf(int partnum), hexdump(int partnum), openFiles(const char *path), - cmd_copy(void), parseMacString(const char *strMac, uint16_t *mac); + cmd_copy(void), parseMacString(const char *strMac, uint16_t *mac), + cmd_swap(void); int goodChecksum(int partnum); uint8_t hextonum(char chs), rhex(void); @@ -46,7 +47,7 @@ typedef struct op { op_t op[] = { { .str = "dump", .cmd = cmd_dump, .args = 3}, { .str = "setmac", .cmd = cmd_setmac, .args = 3}, -{ .str = "swap", .cmd = writeGbe, .args = 3}, +{ .str = "swap", .cmd = cmd_swap, .args = 3}, { .str = "copy", .cmd = cmd_copy, .args = 4}, { .str = "brick", .cmd = cmd_brick, .args = 4}, { .str = "setchecksum", .cmd = cmd_setchecksum, .args = 4}, @@ -148,8 +149,8 @@ main(int argc, char *argv[]) readGbe(); /* read gbe file into memory */ (*cmd)(); /* operate on gbe file in memory, as per user command */ - if ((gbeFileChanged) && (flags != O_RDONLY) && (cmd != writeGbe)) - writeGbe(); /* not called for swap cmd; swap calls writeGbe */ + if ((gbeFileChanged) && (flags != O_RDONLY)) + writeGbe(); err_if((errno != 0) && (cmd != cmd_dump)); /* don't err on dump */ return errno; /* errno can be set by the dump command */ @@ -197,7 +198,7 @@ openFiles(const char *path) void readGbe(void) { - if ((cmd == writeGbe) || (cmd == cmd_copy)) + if ((cmd == cmd_swap) || (cmd == cmd_copy)) nf = partsize; /* read/write the entire block */ else nf = 128; /* only read/write the nvm part of the block */ @@ -378,6 +379,20 @@ cmd_copy(void) /* we simply set the right nvm part as changed, and write the file */ } +/* swap contents between the two parts */ +void +cmd_swap(void) { + err_if(!(goodChecksum(0) || goodChecksum(1))); + errno = 0; + + /* speedhack: swap pointers, not words. (xor swap) */ + gbe[0] ^= gbe[1]; + gbe[1] ^= gbe[0]; + gbe[0] ^= gbe[1]; + + gbeFileChanged = nvmPartChanged[0] = nvmPartChanged[1] = 1; +} + /* verify nvm part checksum (return 1 if valid) */ int goodChecksum(int partnum) @@ -398,16 +413,13 @@ goodChecksum(int partnum) void writeGbe(void) { - if (cmd == writeGbe) /* cmd swap calls writeGbE; need valid checksum */ - err_if(!(goodChecksum(0) || goodChecksum(1))); - - for (int p = 0, x = (cmd == writeGbe) ? 1 : 0; p < 2; p++) { - if ((!nvmPartChanged[p]) && (cmd != writeGbe)) + for (int p = 0; p < 2; p++) { + if ((!nvmPartChanged[p])) continue; - swap(p ^ x); /* swap bytes on big-endian host CPUs */ + swap(p); /* swap bytes on big-endian host CPUs */ - err_if(pwrite(fd, (uint8_t *) gbe[p ^ x], nf, p * partsize) + err_if(pwrite(fd, (uint8_t *) gbe[p], nf, p * partsize) == -1); } @@ -417,8 +429,8 @@ writeGbe(void) /* swap byte order on big-endian CPUs. swap skipped on little endian */ void -swap(int partnum) -{ +swap(int partnum) /* swaps bytes in words, not pointers. */ +{ /* not to be confused with cmd_swap */ size_t w, x; uint8_t *n = (uint8_t *) gbe[partnum]; |