From 6e5828e4a8d11ce7f6d8a4868a6e0afa54e6ebf0 Mon Sep 17 00:00:00 2001 From: lbmkplaceholder Date: Fri, 23 Dec 2022 08:41:18 +0000 Subject: util/nvmutil: greatly optimise cmd_swap() instead of XOR-swapping every byte, have pointers to the two parts and *XOR swap the pointers*. at the end of the program execution, when writing, pwrite the two parts into the same file --- util/nvmutil/nvmutil.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) (limited to 'util') diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 80d515f7..b80616ae 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -57,7 +57,7 @@ void writeGbeFile(int *fd, const char *filename); #define SIZE_4KB 0x1000 #define SIZE_8KB 0x2000 -uint8_t gbe[SIZE_8KB]; +uint8_t *gbe = NULL, *gbe2 = NULL; int part, gbeFileModified = 0; uint8_t nvmPartModified[2]; @@ -73,6 +73,10 @@ main(int argc, char *argv[]) char *strRMac = "??:??:??:??:??:??"; void (*cmd)(void) = NULL; + if ((gbe = (uint8_t *) malloc(SIZE_8KB)) == NULL) + err(errno, NULL); + gbe2 = gbe + SIZE_4KB; + nvmPartModified[0] = 0; nvmPartModified[1] = 0; @@ -351,16 +355,18 @@ void cmd_swap(void) { int part0, part1; + size_t g1 = (size_t) gbe; + size_t g2 = (size_t) gbe2; part0 = validChecksum(0); part1 = validChecksum(1); if (part0 || part1) { - for(part0 = 0; part0 < SIZE_4KB; part0++) { - gbe[part0] ^= gbe[part1 = (part0 | SIZE_4KB)]; - gbe[part1] ^= gbe[part0]; - gbe[part0] ^= gbe[part1]; - } + g1 ^= g2; + g2 ^= g1; + g1 ^= g2; + gbe = (uint8_t *) g1; + gbe2 = (uint8_t *) g2; gbeFileModified = 1; nvmPartModified[0] = 1; @@ -438,9 +444,12 @@ writeGbeFile(int *fd, const char *filename) int partnum; errno = 0; - if (pwrite((*fd), gbe, SIZE_8KB, 0) == SIZE_8KB) - if (close((*fd))) - err(errno, "%s", filename); + if (pwrite((*fd), gbe, SIZE_4KB, 0) != SIZE_4KB) + err(errno, "%s", filename); + if (pwrite((*fd), gbe2, SIZE_4KB, SIZE_4KB) != SIZE_4KB) + err(errno, "%s", filename); + if (close((*fd))) + err(errno, "%s", filename); if (errno != 0) return; -- cgit v1.2.1