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util/nvmutil: do xor swap in a macro 

eventually, everything will be a macro!

Signed-off-by: Leah Rowe <leah@libreboot.org>
fsdg20230625
Leah Rowe 2023-06-01 07:21:30 +01:00
parent 293ca0fcbb
commit 7ab209d545
1 changed files with 8 additions and 14 deletions
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22
util/nvmutil/nvmutil.c
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@ -53,7 +53,7 @@ void cmd_swap(void);
void cmd_copy(void);
int validChecksum(int partnum);
void setWord(int pos16, int partnum, uint16_t val16);
void byteswap(int n, int partnum);
void xorswap_buf(int n, int partnum);
void writeGbeFile(int *fd, const char *filename, size_t nw);
void xpledge(const char *promises, const char *execpromises);
void xunveil(const char *path, const char *permissions);
@ -68,6 +68,7 @@ void err_if(int condition);
#define word(pos16, partnum) (buf16[pos16 + (partnum << 11)])
#define ERR() (errno = errno ? errno : ECANCELED)
#define xorswap(x, y) x ^= y, y ^= x, x ^= y
uint16_t buf16[SIZE_4KB];
uint8_t *buf;
@ -166,7 +167,7 @@ readGbeFile(int *fd, const char *path, int flags, size_t nr)
if (pread((*fd), (uint8_t *) gbe[p], nr, p << 12) == -1)
err(ERR(), "%s", path);
if (big_endian)
byteswap(nr, p);
xorswap_buf(nr, p);
}
}
@ -298,9 +299,7 @@ cmd_brick(void)
void
cmd_swap(void)
{
gbe[0] ^= gbe[1]; /* speedhack: swap ptr, not words */
gbe[1] ^= gbe[0];
gbe[0] ^= gbe[1];
xorswap(gbe[0], gbe[1]); /* speedhack: swap ptr, not words */
gbeFileModified = nvmPartModified[0] = nvmPartModified[1]
= validChecksum(1) | validChecksum(0);
}
@ -335,16 +334,11 @@ setWord(int pos16, int partnum, uint16_t val16)
}
void
byteswap(int n, int partnum)
xorswap_buf(int n, int partnum)
{
int b1, b2, wcount = n >> 1;
uint8_t *nbuf = (uint8_t *) gbe[partnum];
for (int w = 0; w < wcount; w++) {
b1 = b2 = w << 1;
nbuf[b1] ^= nbuf[++b2]; /* xor swap */
nbuf[b2] ^= nbuf[b1];
nbuf[b1] ^= nbuf[b2];
}
for (int w = 0; w < (n >> 1); w++)
xorswap(nbuf[w << 1], nbuf[(w << 1) + 1]);
}
void
@ -358,7 +352,7 @@ writeGbeFile(int *fd, const char *filename, size_t nw)
if (!nvmPartModified[p])
goto next_part;
if (big_endian)
byteswap(nw, p);
xorswap_buf(nw, p);
if (pwrite((*fd), (uint8_t *) gbe[p], nw, p << 12) == -1)
err(ERR(), "%s", filename);
next_part: