Bus Pirate buffer management revamp
The buffer management of the Bus Pirate driver has been revamped to use
grow-only buffers with a reasonable initial default size so realloc()
will not have to be called in normal operation. A side effect is the
ability to switch to a static buffer without major hassle.
Handle OOM gracefully.
Corresponding to flashrom svn r1541.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/buspirate_spi.c b/buspirate_spi.c
index f816afd..848868c 100644
--- a/buspirate_spi.c
+++ b/buspirate_spi.c
@@ -39,6 +39,7 @@
{
/* 115200bps, 8 databits, no parity, 1 stopbit */
sp_fd = sp_openserport(dev, 115200);
+ /* FIXME: Error checking */
return 0;
}
#else
@@ -49,6 +50,29 @@
#define sp_flush_incoming(...) 0
#endif
+static unsigned char *bp_commbuf = NULL;
+static int bp_commbufsize = 0;
+
+static int buspirate_commbuf_grow(int bufsize)
+{
+ unsigned char *tmpbuf;
+
+ /* Never shrink. realloc() calls are expensive. */
+ if (bufsize <= bp_commbufsize)
+ return 0;
+
+ tmpbuf = realloc(bp_commbuf, bufsize);
+ if (!tmpbuf) {
+ /* Keep the existing buffer because memory is already tight. */
+ msg_perr("Out of memory!\n");
+ return ERROR_OOM;
+ }
+
+ bp_commbuf = tmpbuf;
+ bp_commbufsize = bufsize;
+ return 0;
+}
+
static int buspirate_sendrecv(unsigned char *buf, unsigned int writecnt,
unsigned int readcnt)
{
@@ -116,42 +140,48 @@
static int buspirate_spi_shutdown(void *data)
{
- unsigned char buf[5];
- int ret = 0;
+ int ret = 0, ret2 = 0;
+ /* No need to allocate a buffer here, we know that bp_commbuf is at least DEFAULT_BUFSIZE big. */
/* Exit raw SPI mode (enter raw bitbang mode) */
- buf[0] = 0x00;
- ret = buspirate_sendrecv(buf, 1, 5);
+ bp_commbuf[0] = 0x00;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 5);
if (ret)
- return ret;
- if (memcmp(buf, "BBIO", 4)) {
+ goto out_shutdown;
+ if (memcmp(bp_commbuf, "BBIO", 4)) {
msg_perr("Entering raw bitbang mode failed!\n");
- return 1;
+ ret = 1;
+ goto out_shutdown;
}
- msg_pdbg("Raw bitbang mode version %c\n", buf[4]);
- if (buf[4] != '1') {
- msg_perr("Can't handle raw bitbang mode version %c!\n",
- buf[4]);
- return 1;
+ msg_pdbg("Raw bitbang mode version %c\n", bp_commbuf[4]);
+ if (bp_commbuf[4] != '1') {
+ msg_perr("Can't handle raw bitbang mode version %c!\n", bp_commbuf[4]);
+ ret = 1;
+ goto out_shutdown;
}
/* Reset Bus Pirate (return to user terminal) */
- buf[0] = 0x0f;
- ret = buspirate_sendrecv(buf, 1, 0);
- if (ret)
- return ret;
+ bp_commbuf[0] = 0x0f;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 0);
+out_shutdown:
/* Shut down serial port communication */
- ret = serialport_shutdown(NULL);
+ ret2 = serialport_shutdown(NULL);
+ /* Keep the oldest error, it is probably the best indicator. */
+ if (ret2 && !ret)
+ ret = ret2;
+ bp_commbufsize = 0;
+ free(bp_commbuf);
+ bp_commbuf = NULL;
if (ret)
- return ret;
- msg_pdbg("Bus Pirate shutdown completed.\n");
+ msg_pdbg("Bus Pirate shutdown failed.\n");
+ else
+ msg_pdbg("Bus Pirate shutdown completed.\n");
- return 0;
+ return ret;
}
int buspirate_spi_init(void)
{
- unsigned char buf[512];
char *dev = NULL;
char *speed = NULL;
int spispeed = 0x7;
@@ -181,10 +211,24 @@
/* This works because speeds numbering starts at 0 and is contiguous. */
msg_pdbg("SPI speed is %sHz\n", spispeeds[spispeed].name);
+ /* Default buffer size is 19: 16 bytes data, 3 bytes control. */
+#define DEFAULT_BUFSIZE (16 + 3)
+ bp_commbuf = malloc(DEFAULT_BUFSIZE);
+ if (!bp_commbuf) {
+ bp_commbufsize = 0;
+ msg_perr("Out of memory!\n");
+ return ERROR_OOM;
+ }
+ bp_commbufsize = DEFAULT_BUFSIZE;
+
ret = buspirate_serialport_setup(dev);
- if (ret)
- return ret;
free(dev);
+ if (ret) {
+ bp_commbufsize = 0;
+ free(bp_commbuf);
+ bp_commbuf = NULL;
+ return ret;
+ }
if (register_shutdown(buspirate_spi_shutdown, NULL))
return 1;
@@ -192,9 +236,9 @@
/* This is the brute force version, but it should work. */
for (i = 0; i < 19; i++) {
/* Enter raw bitbang mode */
- buf[0] = 0x00;
+ bp_commbuf[0] = 0x00;
/* Send the command, don't read the response. */
- ret = buspirate_sendrecv(buf, 1, 0);
+ ret = buspirate_sendrecv(bp_commbuf, 1, 0);
if (ret)
return ret;
/* Read any response and discard it. */
@@ -215,76 +259,78 @@
sp_flush_incoming();
}
/* Enter raw bitbang mode */
- buf[0] = 0x00;
- ret = buspirate_sendrecv(buf, 1, 5);
+ bp_commbuf[0] = 0x00;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 5);
if (ret)
return ret;
- if (memcmp(buf, "BBIO", 4)) {
+ if (memcmp(bp_commbuf, "BBIO", 4)) {
msg_perr("Entering raw bitbang mode failed!\n");
msg_pdbg("Got %02x%02x%02x%02x%02x\n",
- buf[0], buf[1], buf[2], buf[3], buf[4]);
+ bp_commbuf[0], bp_commbuf[1], bp_commbuf[2],
+ bp_commbuf[3], bp_commbuf[4]);
return 1;
}
- msg_pdbg("Raw bitbang mode version %c\n", buf[4]);
- if (buf[4] != '1') {
+ msg_pdbg("Raw bitbang mode version %c\n", bp_commbuf[4]);
+ if (bp_commbuf[4] != '1') {
msg_perr("Can't handle raw bitbang mode version %c!\n",
- buf[4]);
+ bp_commbuf[4]);
return 1;
}
/* Enter raw SPI mode */
- buf[0] = 0x01;
- ret = buspirate_sendrecv(buf, 1, 4);
+ bp_commbuf[0] = 0x01;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 4);
if (ret)
return ret;
- if (memcmp(buf, "SPI", 3)) {
+ if (memcmp(bp_commbuf, "SPI", 3)) {
msg_perr("Entering raw SPI mode failed!\n");
msg_pdbg("Got %02x%02x%02x%02x\n",
- buf[0], buf[1], buf[2], buf[3]);
+ bp_commbuf[0], bp_commbuf[1], bp_commbuf[2],
+ bp_commbuf[3]);
return 1;
}
- msg_pdbg("Raw SPI mode version %c\n", buf[3]);
- if (buf[3] != '1') {
+ msg_pdbg("Raw SPI mode version %c\n", bp_commbuf[3]);
+ if (bp_commbuf[3] != '1') {
msg_perr("Can't handle raw SPI mode version %c!\n",
- buf[3]);
+ bp_commbuf[3]);
return 1;
}
/* Initial setup (SPI peripherals config): Enable power, CS high, AUX */
- buf[0] = 0x40 | 0xb;
- ret = buspirate_sendrecv(buf, 1, 1);
+ bp_commbuf[0] = 0x40 | 0xb;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
- if (buf[0] != 0x01) {
+ if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while setting power/CS/AUX!\n");
return 1;
}
/* Set SPI speed */
- buf[0] = 0x60 | spispeed;
- ret = buspirate_sendrecv(buf, 1, 1);
+ bp_commbuf[0] = 0x60 | spispeed;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
- if (buf[0] != 0x01) {
+ if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while setting SPI speed!\n");
return 1;
}
/* Set SPI config: output type, idle, clock edge, sample */
- buf[0] = 0x80 | 0xa;
- ret = buspirate_sendrecv(buf, 1, 1);
+ bp_commbuf[0] = 0x80 | 0xa;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
- if (buf[0] != 0x01) {
+ if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while setting SPI config!\n");
return 1;
}
/* De-assert CS# */
- buf[0] = 0x03;
- ret = buspirate_sendrecv(buf, 1, 1);
+ bp_commbuf[0] = 0x03;
+ ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
- if (buf[0] != 0x01) {
+ if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while raising CS#!\n");
return 1;
}
@@ -300,7 +346,6 @@
const unsigned char *writearr,
unsigned char *readarr)
{
- static unsigned char *buf = NULL;
unsigned int i = 0;
int ret = 0;
@@ -308,48 +353,45 @@
return SPI_INVALID_LENGTH;
/* 3 bytes extra for CS#, len, CS#. */
- buf = realloc(buf, writecnt + readcnt + 3);
- if (!buf) {
- msg_perr("Out of memory!\n");
- exit(1); // -1
- }
+ if (buspirate_commbuf_grow(writecnt + readcnt + 3))
+ return ERROR_OOM;
/* Assert CS# */
- buf[i++] = 0x02;
+ bp_commbuf[i++] = 0x02;
- buf[i++] = 0x10 | (writecnt + readcnt - 1);
- memcpy(buf + i, writearr, writecnt);
+ bp_commbuf[i++] = 0x10 | (writecnt + readcnt - 1);
+ memcpy(bp_commbuf + i, writearr, writecnt);
i += writecnt;
- memset(buf + i, 0, readcnt);
+ memset(bp_commbuf + i, 0, readcnt);
i += readcnt;
/* De-assert CS# */
- buf[i++] = 0x03;
+ bp_commbuf[i++] = 0x03;
- ret = buspirate_sendrecv(buf, i, i);
+ ret = buspirate_sendrecv(bp_commbuf, i, i);
if (ret) {
msg_perr("Bus Pirate communication error!\n");
return SPI_GENERIC_ERROR;
}
- if (buf[0] != 0x01) {
+ if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while lowering CS#!\n");
return SPI_GENERIC_ERROR;
}
- if (buf[1] != 0x01) {
+ if (bp_commbuf[1] != 0x01) {
msg_perr("Protocol error while reading/writing SPI!\n");
return SPI_GENERIC_ERROR;
}
- if (buf[i - 1] != 0x01) {
+ if (bp_commbuf[i - 1] != 0x01) {
msg_perr("Protocol error while raising CS#!\n");
return SPI_GENERIC_ERROR;
}
/* Skip CS#, length, writearr. */
- memcpy(readarr, buf + 2 + writecnt, readcnt);
+ memcpy(readarr, bp_commbuf + 2 + writecnt, readcnt);
return ret;
}