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PureOS / Core Packages / flashrom
8 commits behind, 59 commits ahead of the upstream repository.
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Edward O'Callaghan authored
The ChromiumOS flashrom fork has since const'ify flashctx in a few places. This aligns the function signatures to match with downstream to ease forward porting patches out of downstream back into mainline flashrom. This patch is minimum viable alignment and so feedback is welcome. Change-Id: Iff6dbda13cb0d941481c0d204b9c30895630fbd1 Signed-off-by:
Edward O'Callaghan <quasisec@google.com> Reviewed-on: https://review.coreboot.org/c/flashrom/+/40324 Reviewed-by:
Angel Pons <th3fanbus@gmail.com> Tested-by:
build bot (Jenkins) <no-reply@coreboot.org>
Edward O'Callaghan authoredThe ChromiumOS flashrom fork has since const'ify flashctx in a few places. This aligns the function signatures to match with downstream to ease forward porting patches out of downstream back into mainline flashrom. This patch is minimum viable alignment and so feedback is welcome. Change-Id: Iff6dbda13cb0d941481c0d204b9c30895630fbd1 Signed-off-by:
Edward O'Callaghan <quasisec@google.com> Reviewed-on: https://review.coreboot.org/c/flashrom/+/40324 Reviewed-by:
Angel Pons <th3fanbus@gmail.com> Tested-by:
build bot (Jenkins) <no-reply@coreboot.org>
buspirate_spi.c 19.02 KiB
/*
* This file is part of the flashrom project.
*
* Copyright (C) 2009, 2010, 2011, 2012 Carl-Daniel Hailfinger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#include <strings.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>
#include "flash.h"
#include "programmer.h"
#include "spi.h"
/* Change this to #define if you want to test without a serial implementation */
#undef FAKE_COMMUNICATION
struct buspirate_speeds {
const char *name;
const int speed;
};
#define BP_DEFAULTBAUD 115200
#ifndef FAKE_COMMUNICATION
static int buspirate_serialport_setup(char *dev)
{
/* 115200bps, 8 databits, no parity, 1 stopbit */
sp_fd = sp_openserport(dev, BP_DEFAULTBAUD);
if (sp_fd == SER_INV_FD)
return 1;
return 0;
}
#else
#define buspirate_serialport_setup(...) 0
#define serialport_shutdown(...) 0
#define serialport_write(...) 0
#define serialport_read(...) 0
#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)
{
unsigned int i;
int ret = 0;
msg_pspew("%s: write %i, read %i ", __func__, writecnt, readcnt);
if (!writecnt && !readcnt) {
msg_perr("Zero length command!\n");
return 1;
}
if (writecnt)
msg_pspew("Sending");
for (i = 0; i < writecnt; i++)
msg_pspew(" 0x%02x", buf[i]);
#ifdef FAKE_COMMUNICATION
/* Placate the caller for now. */
if (readcnt) {
buf[0] = 0x01;
memset(buf + 1, 0xff, readcnt - 1);
}
ret = 0;
#else
if (writecnt)
ret = serialport_write(buf, writecnt);
if (ret)
return ret;
if (readcnt)
ret = serialport_read(buf, readcnt);
if (ret)
return ret;
#endif
if (readcnt)
msg_pspew(", receiving");
for (i = 0; i < readcnt; i++)
msg_pspew(" 0x%02x", buf[i]);
msg_pspew("\n");
return 0;
}
static int buspirate_wait_for_string(unsigned char *buf, const char *key)
{
unsigned int keylen = strlen(key);
int ret;
ret = buspirate_sendrecv(buf, 0, keylen);
while (!ret) {
if (!memcmp(buf, key, keylen))
return 0;
memmove(buf, buf + 1, keylen - 1);
ret = buspirate_sendrecv(buf + keylen - 1, 0, 1);
}
return ret;
}
static int buspirate_spi_send_command_v1(const struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr);
static int buspirate_spi_send_command_v2(const struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr);
static struct spi_master spi_master_buspirate = {
.features = SPI_MASTER_4BA,
.max_data_read = MAX_DATA_UNSPECIFIED,
.max_data_write = MAX_DATA_UNSPECIFIED,
.command = NULL,
.multicommand = default_spi_send_multicommand,
.read = default_spi_read,
.write_256 = default_spi_write_256,
.write_aai = default_spi_write_aai,
};
static const struct buspirate_speeds spispeeds[] = {
{"30k", 0x0},
{"125k", 0x1},
{"250k", 0x2},
{"1M", 0x3},
{"2M", 0x4},
{"2.6M", 0x5},
{"4M", 0x6},
{"8M", 0x7},
{NULL, 0x0}
};
static const struct buspirate_speeds serialspeeds[] = {
{"115200", 115200},
{"230400", 230400},
{"250000", 250000},
{"2000000", 2000000},
{"2M", 2000000},
{NULL, 0}
};
static int buspirate_spi_shutdown(void *data)
{
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) */
bp_commbuf[0] = 0x00;
if ((ret = buspirate_sendrecv(bp_commbuf, 1, 0)))
goto out_shutdown;
if ((ret = buspirate_wait_for_string(bp_commbuf, "BBIO")))
goto out_shutdown;
if ((ret = buspirate_sendrecv(bp_commbuf, 0, 1)))
goto out_shutdown;
msg_pdbg("Raw bitbang mode version %c\n", bp_commbuf[0]);
if (bp_commbuf[0] != '1') {
msg_perr("Can't handle raw bitbang mode version %c!\n", bp_commbuf[0]);
ret = 1;
goto out_shutdown;
}
/* Reset Bus Pirate (return to user terminal) */
bp_commbuf[0] = 0x0f;
ret = buspirate_sendrecv(bp_commbuf, 1, 0);
out_shutdown:
/* Shut down serial port communication */
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)
msg_pdbg("Bus Pirate shutdown failed.\n");
else
msg_pdbg("Bus Pirate shutdown completed.\n");
return ret;
}
#define BP_FWVERSION(a,b) ((a) << 8 | (b))
#define BP_HWVERSION(a,b) BP_FWVERSION(a,b)
/**
* The Bus Pirate's PIC microcontroller supports custom baud rates by manually specifying a
* clock divisor that can be calculated with the formula (16000000 / (4 * baud)) - 1.
*/
#define BP_DIVISOR(baud) ((4000000/(baud)) - 1)
int buspirate_spi_init(void)
{
char *tmp;
char *dev;
int i;
int cnt;
unsigned int fw_version_major = 0;
unsigned int fw_version_minor = 0;
unsigned int hw_version_major = 0;
unsigned int hw_version_minor = 0;
int spispeed = 0x7;
int serialspeed_index = -1;
int ret = 0;
int pullup = 0;
dev = extract_programmer_param("dev");
if (dev && !strlen(dev)) {
free(dev);
dev = NULL;
}
if (!dev) {
msg_perr("No serial device given. Use flashrom -p buspirate_spi:dev=/dev/ttyUSB0\n");
return 1;
}
tmp = extract_programmer_param("spispeed");
if (tmp) {
for (i = 0; spispeeds[i].name; i++) {
if (!strncasecmp(spispeeds[i].name, tmp, strlen(spispeeds[i].name))) {
spispeed = spispeeds[i].speed;
break;
}
}
if (!spispeeds[i].name)
msg_perr("Invalid SPI speed, using default.\n");
}
free(tmp);
/* Extract serialspeed parameter */
tmp = extract_programmer_param("serialspeed");
if (tmp) {
for (i = 0; serialspeeds[i].name; i++) {
if (!strncasecmp(serialspeeds[i].name, tmp, strlen(serialspeeds[i].name))) {
serialspeed_index = i;
break;
}
}
if (!serialspeeds[i].name)
msg_perr("Invalid serial speed %s, using default.\n", tmp);
}
free(tmp);
tmp = extract_programmer_param("pullups");
if (tmp) {
if (strcasecmp("on", tmp) == 0)
pullup = 1;
else if (strcasecmp("off", tmp) == 0)
; // ignore
else
msg_perr("Invalid pullups state, not using them.\n");
}
free(tmp);
/* 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");
free(dev);
return ERROR_OOM;
}
bp_commbufsize = DEFAULT_BUFSIZE;
ret = buspirate_serialport_setup(dev);
free(dev);
if (ret) {
bp_commbufsize = 0;
free(bp_commbuf);
bp_commbuf = NULL;
return ret;
}
if (register_shutdown(buspirate_spi_shutdown, NULL) != 0) {
bp_commbufsize = 0;
free(bp_commbuf);
bp_commbuf = NULL;
return 1;
}
/* This is the brute force version, but it should work.
* It is likely to fail if a previous flashrom run was aborted during a write with the new SPI commands
* in firmware v5.5 because that firmware may wait for up to 4096 bytes of input before responding to
* 0x00 again. The obvious workaround (sending 4096 bytes of \0) may cause significant startup delays.
*/
for (i = 0; i < 20; i++) {
/* Enter raw bitbang mode */
bp_commbuf[0] = 0x00;
/* Send the command, don't read the response. */
ret = buspirate_sendrecv(bp_commbuf, 1, 0);
if (ret)
return ret;
/* The old way to handle responses from a Bus Pirate already in BBIO mode was to flush any
* response which came in over serial. Unfortunately that does not work reliably on Linux
* with FTDI USB-serial.
*/
//sp_flush_incoming();
/* The Bus Pirate can't handle UART input buffer overflow in BBIO mode, and sending a sequence
* of 0x00 too fast apparently triggers such an UART input buffer overflow.
*/
internal_sleep(10000);
}
/* We know that 20 commands of \0 should elicit at least one BBIO1 response. */
if ((ret = buspirate_wait_for_string(bp_commbuf, "BBIO")))
return ret;
/* Reset the Bus Pirate. */
bp_commbuf[0] = 0x0f;
/* Send the command, don't read the response. */
if ((ret = buspirate_sendrecv(bp_commbuf, 1, 0)))
return ret;
if ((ret = buspirate_wait_for_string(bp_commbuf, "irate ")))
return ret;
/* Read the hardware version string. Last byte of the buffer is reserved for \0. */
for (i = 0; i < DEFAULT_BUFSIZE - 1; i++) {
if ((ret = buspirate_sendrecv(bp_commbuf + i, 0, 1)))
return ret;
if (strchr("\r\n\t ", bp_commbuf[i]))
break;
}
bp_commbuf[i] = '\0';
msg_pdbg("Detected Bus Pirate hardware ");
if (bp_commbuf[0] != 'v')
msg_pdbg("(unknown version number format)");
else if (!strchr("0123456789", bp_commbuf[1]))
msg_pdbg("(unknown version number format)");
else {
hw_version_major = strtoul((char *)bp_commbuf + 1, &tmp, 10);
while ((*tmp != '\0') && !strchr("0123456789", *tmp))
tmp++;
hw_version_minor = strtoul(tmp, NULL, 10);
msg_pdbg("%u.%u", hw_version_major, hw_version_minor);
}
msg_pdbg2(" (\"%s\")", bp_commbuf);
msg_pdbg("\n");
if ((ret = buspirate_wait_for_string(bp_commbuf, "irmware ")))
return ret;
/* Read the firmware version string. Last byte of the buffer is reserved for \0. */
for (i = 0; i < DEFAULT_BUFSIZE - 1; i++) {
if ((ret = buspirate_sendrecv(bp_commbuf + i, 0, 1)))
return ret;
if (strchr("\r\n\t ", bp_commbuf[i]))
break;
}
bp_commbuf[i] = '\0';
msg_pdbg("Detected Bus Pirate firmware ");
if (bp_commbuf[0] != 'v')
msg_pdbg("(unknown version number format)");
else if (!strchr("0123456789", bp_commbuf[1]))
msg_pdbg("(unknown version number format)");
else {
fw_version_major = strtoul((char *)bp_commbuf + 1, &tmp, 10);
while ((*tmp != '\0') && !strchr("0123456789", *tmp))
tmp++;
fw_version_minor = strtoul(tmp, NULL, 10);
msg_pdbg("%u.%u", fw_version_major, fw_version_minor);
}
msg_pdbg2(" (\"%s\")", bp_commbuf);
msg_pdbg("\n");
if ((ret = buspirate_wait_for_string(bp_commbuf, "HiZ>")))
return ret;
/* Tell the user about missing SPI binary mode in firmware 2.3 and older. */
if (BP_FWVERSION(fw_version_major, fw_version_minor) < BP_FWVERSION(2, 4)) {
msg_pinfo("Bus Pirate firmware 2.3 and older does not support binary SPI access.\n");
msg_pinfo("Please upgrade to the latest firmware (at least 2.4).\n");
return SPI_PROGRAMMER_ERROR;
}
/* Use fast SPI mode in firmware 5.5 and newer. */
if (BP_FWVERSION(fw_version_major, fw_version_minor) >= BP_FWVERSION(5, 5)) {
msg_pdbg("Using SPI command set v2.\n");
/* Sensible default buffer size. */
if (buspirate_commbuf_grow(260 + 5))
return ERROR_OOM;
spi_master_buspirate.max_data_read = 2048;
spi_master_buspirate.max_data_write = 256;
spi_master_buspirate.command = buspirate_spi_send_command_v2;
} else {
msg_pinfo("Bus Pirate firmware 5.4 and older does not support fast SPI access.\n");
msg_pinfo("Reading/writing a flash chip may take hours.\n");
msg_pinfo("It is recommended to upgrade to firmware 5.5 or newer.\n");
/* Sensible default buffer size. */
if (buspirate_commbuf_grow(16 + 3))
return ERROR_OOM;
spi_master_buspirate.max_data_read = 12;
spi_master_buspirate.max_data_write = 12;
spi_master_buspirate.command = buspirate_spi_send_command_v1;
}
/* Workaround for broken speed settings in firmware 6.1 and older. */
if (BP_FWVERSION(fw_version_major, fw_version_minor) < BP_FWVERSION(6, 2))
if (spispeed > 0x4) {
msg_perr("Bus Pirate firmware 6.1 and older does not support SPI speeds above 2 MHz. "
"Limiting speed to 2 MHz.\n");
msg_pinfo("It is recommended to upgrade to firmware 6.2 or newer.\n");
spispeed = 0x4;
}
/* This works because speeds numbering starts at 0 and is contiguous. */
msg_pdbg("SPI speed is %sHz\n", spispeeds[spispeed].name);
/* Set 2M baud serial speed by default on hardware 3.0 and newer if a custom speed was not set */
if (serialspeed_index == -1 && BP_HWVERSION(hw_version_major, hw_version_minor) >= BP_HWVERSION(3, 0)) {
serialspeed_index = ARRAY_SIZE(serialspeeds) - 2;
msg_pdbg("Bus Pirate v3 or newer detected. Set serial speed to 2M baud.\n");
}
/* Set custom serial speed if specified */
if (serialspeed_index != -1) {
if (BP_FWVERSION(fw_version_major, fw_version_minor) < BP_FWVERSION(5, 5)) {
/* This feature requires firmware 5.5 or newer */
msg_perr("Bus Pirate firmware 5.4 and older does not support custom serial speeds."
"Using default speed of 115200 baud.\n");
} else if (serialspeeds[serialspeed_index].speed != BP_DEFAULTBAUD) {
/* Set the serial speed to match the user's choice if it doesn't already */
if (BP_HWVERSION(hw_version_major, hw_version_minor) < BP_HWVERSION(3, 0))
msg_pwarn("Increased serial speeds may not work on older (<3.0) Bus Pirates."
" Continue at your own risk.\n");
/* Enter baud rate configuration mode */
cnt = snprintf((char *)bp_commbuf, DEFAULT_BUFSIZE, "b\n");
if ((ret = buspirate_sendrecv(bp_commbuf, cnt, 0)))
return ret;
if ((ret = buspirate_wait_for_string(bp_commbuf, ">")))
return ret;
/* Enter manual clock divisor entry mode */
cnt = snprintf((char *)bp_commbuf, DEFAULT_BUFSIZE, "10\n");
if ((ret = buspirate_sendrecv(bp_commbuf, cnt, 0)))
return ret;
if ((ret = buspirate_wait_for_string(bp_commbuf, ">")))
return ret;
/* Set the clock divisor to the value calculated from the user's input */
cnt = snprintf((char *)bp_commbuf, DEFAULT_BUFSIZE, "%d\n",
BP_DIVISOR(serialspeeds[serialspeed_index].speed));
if ((ret = buspirate_sendrecv(bp_commbuf, cnt, 0)))
return ret;
sleep(1);
/* Reconfigure the host's serial baud rate to the new value */
if ((ret = serialport_config(sp_fd, serialspeeds[serialspeed_index].speed))) {
msg_perr("Unable to configure system baud rate to specified value.");
return ret;
}
/* Return to the main prompt */
bp_commbuf[0] = ' ';
if ((ret = buspirate_sendrecv(bp_commbuf, 1, 0)))
return ret;
if ((ret = buspirate_wait_for_string(bp_commbuf, "HiZ>")))
return ret;
msg_pdbg("Serial speed is %d baud\n", serialspeeds[serialspeed_index].speed);
}
}
/* Enter raw bitbang mode */
for (i = 0; i < 20; i++) {
bp_commbuf[0] = 0x00;
if ((ret = buspirate_sendrecv(bp_commbuf, 1, 0)))
return ret;
}
if ((ret = buspirate_wait_for_string(bp_commbuf, "BBIO")))
return ret;
if ((ret = buspirate_sendrecv(bp_commbuf, 0, 1)))
return ret;
msg_pdbg("Raw bitbang mode version %c\n", bp_commbuf[0]);
if (bp_commbuf[0] != '1') {
msg_perr("Can't handle raw bitbang mode version %c!\n", bp_commbuf[0]);
return 1;
}
/* Enter raw SPI mode */
bp_commbuf[0] = 0x01;
ret = buspirate_sendrecv(bp_commbuf, 1, 0);
if (ret)
return 1;
if ((ret = buspirate_wait_for_string(bp_commbuf, "SPI")))
return ret;
if ((ret = buspirate_sendrecv(bp_commbuf, 0, 1)))
return ret;
msg_pdbg("Raw SPI mode version %c\n", bp_commbuf[0]);
if (bp_commbuf[0] != '1') {
msg_perr("Can't handle raw SPI mode version %c!\n", bp_commbuf[0]);
return 1;
}
/* Initial setup (SPI peripherals config): Enable power, CS high, AUX */
bp_commbuf[0] = 0x40 | 0x0b;
if (pullup == 1) {
bp_commbuf[0] |= (1 << 2);
msg_pdbg("Enabling pull-up resistors.\n");
}
ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while setting power/CS/AUX(/Pull-up resistors)!\n");
return 1;
}
/* Set SPI speed */
bp_commbuf[0] = 0x60 | spispeed;
ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
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 */
bp_commbuf[0] = 0x80 | 0xa;
if (pullup == 1) {
bp_commbuf[0] &= ~(1 << 3);
msg_pdbg("Pull-ups enabled, so using HiZ pin output! (Open-Drain mode)\n");
}
ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while setting SPI config!\n");
return 1;
}
/* De-assert CS# */
bp_commbuf[0] = 0x03;
ret = buspirate_sendrecv(bp_commbuf, 1, 1);
if (ret)
return 1;
if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while raising CS#!\n");
return 1;
}
register_spi_master(&spi_master_buspirate);
return 0;
}
static int buspirate_spi_send_command_v1(const struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr)
{
unsigned int i = 0;
int ret = 0;
if (writecnt > 16 || readcnt > 16 || (readcnt + writecnt) > 16)
return SPI_INVALID_LENGTH;
/* 3 bytes extra for CS#, len, CS#. */
if (buspirate_commbuf_grow(writecnt + readcnt + 3))
return ERROR_OOM;
/* Assert CS# */
bp_commbuf[i++] = 0x02;
bp_commbuf[i++] = 0x10 | (writecnt + readcnt - 1);
memcpy(bp_commbuf + i, writearr, writecnt);
i += writecnt;
memset(bp_commbuf + i, 0, readcnt);
i += readcnt;
/* De-assert CS# */
bp_commbuf[i++] = 0x03;
ret = buspirate_sendrecv(bp_commbuf, i, i);
if (ret) {
msg_perr("Bus Pirate communication error!\n");
return SPI_GENERIC_ERROR;
}
if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while lowering CS#!\n");
return SPI_GENERIC_ERROR;
}
if (bp_commbuf[1] != 0x01) {
msg_perr("Protocol error while reading/writing SPI!\n");
return SPI_GENERIC_ERROR;
}
if (bp_commbuf[i - 1] != 0x01) {
msg_perr("Protocol error while raising CS#!\n");
return SPI_GENERIC_ERROR;
}
/* Skip CS#, length, writearr. */
memcpy(readarr, bp_commbuf + 2 + writecnt, readcnt);
return ret;
}
static int buspirate_spi_send_command_v2(const struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr)
{
int i = 0, ret = 0;
if (writecnt > 4096 || readcnt > 4096 || (readcnt + writecnt) > 4096)
return SPI_INVALID_LENGTH;
/* 5 bytes extra for command, writelen, readlen.
* 1 byte extra for Ack/Nack.
*/
if (buspirate_commbuf_grow(max(writecnt + 5, readcnt + 1)))
return ERROR_OOM;
/* Combined SPI write/read. */
bp_commbuf[i++] = 0x04;
bp_commbuf[i++] = (writecnt >> 8) & 0xff;
bp_commbuf[i++] = writecnt & 0xff;
bp_commbuf[i++] = (readcnt >> 8) & 0xff;
bp_commbuf[i++] = readcnt & 0xff;
memcpy(bp_commbuf + i, writearr, writecnt);
ret = buspirate_sendrecv(bp_commbuf, i + writecnt, 1 + readcnt);
if (ret) {
msg_perr("Bus Pirate communication error!\n");
return SPI_GENERIC_ERROR;
}
if (bp_commbuf[0] != 0x01) {
msg_perr("Protocol error while sending SPI write/read!\n");
return SPI_GENERIC_ERROR;
}
/* Skip Ack. */
memcpy(readarr, bp_commbuf + 1, readcnt);
return ret;
}