diff --git a/bitbang_spi.c b/bitbang_spi.c
index 5ee52f5..51fc9c6 100644
--- a/bitbang_spi.c
+++ b/bitbang_spi.c
@@ -25,42 +25,37 @@
 #include "programmer.h"
 #include "spi.h"
 
-/* Length of half a clock period in usecs. */
-static int bitbang_spi_half_period;
-
-static const struct bitbang_spi_master *bitbang_spi_master = NULL;
-
 /* Note that CS# is active low, so val=0 means the chip is active. */
-static void bitbang_spi_set_cs(int val)
+static void bitbang_spi_set_cs(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_cs(val);
+	master->set_cs(val);
 }
 
-static void bitbang_spi_set_sck(int val)
+static void bitbang_spi_set_sck(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_sck(val);
+	master->set_sck(val);
 }
 
-static void bitbang_spi_set_mosi(int val)
+static void bitbang_spi_set_mosi(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_mosi(val);
+	master->set_mosi(val);
 }
 
-static int bitbang_spi_get_miso(void)
+static int bitbang_spi_get_miso(const const struct bitbang_spi_master *master)
 {
-	return bitbang_spi_master->get_miso();
+	return master->get_miso();
 }
 
-static void bitbang_spi_request_bus(void)
+static void bitbang_spi_request_bus(const const struct bitbang_spi_master *master)
 {
-	if (bitbang_spi_master->request_bus)
-		bitbang_spi_master->request_bus();
+	if (master->request_bus)
+		master->request_bus();
 }
 
-static void bitbang_spi_release_bus(void)
+static void bitbang_spi_release_bus(const const struct bitbang_spi_master *master)
 {
-	if (bitbang_spi_master->release_bus)
-		bitbang_spi_master->release_bus();
+	if (master->release_bus)
+		master->release_bus();
 }
 
 static int bitbang_spi_send_command(struct flashctx *flash,
@@ -78,67 +73,59 @@
 	.write_256	= default_spi_write_256,
 };
 
-int bitbang_spi_init(const struct bitbang_spi_master *master, int halfperiod)
+#if 0 // until it is needed
+static int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
 {
+	/* FIXME: Run bitbang_spi_release_bus here or per command? */
+	return 0;
+}
+#endif
+
+int bitbang_spi_init(const struct bitbang_spi_master *master)
+{
+	struct spi_programmer pgm = spi_programmer_bitbang;
 	/* BITBANG_SPI_INVALID is 0, so if someone forgot to initialize ->type,
 	 * we catch it here. Same goes for missing initialization of bitbanging
 	 * functions.
 	 */
 	if (!master || master->type == BITBANG_SPI_INVALID || !master->set_cs ||
-	    !master->set_sck || !master->set_mosi || !master->get_miso) {
+	    !master->set_sck || !master->set_mosi || !master->get_miso ||
+	    (master->request_bus && !master->release_bus) ||
+	    (!master->request_bus && master->release_bus)) {
 		msg_perr("Incomplete SPI bitbang master setting!\n"
 			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-	if (bitbang_spi_master) {
-		msg_perr("SPI bitbang master already initialized!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
+		return ERROR_FLASHROM_BUG;
 	}
 
-	bitbang_spi_master = master;
-	bitbang_spi_half_period = halfperiod;
+	pgm.data = master;
+	register_spi_programmer(&pgm);
 
-	register_spi_programmer(&spi_programmer_bitbang);
-
-	/* FIXME: Run bitbang_spi_request_bus here or in programmer init? */
-	bitbang_spi_set_cs(1);
-	bitbang_spi_set_sck(0);
-	bitbang_spi_set_mosi(0);
+	/* Only mess with the bus if we're sure nobody else uses it. */
+	bitbang_spi_request_bus(master);
+	bitbang_spi_set_cs(master, 1);
+	bitbang_spi_set_sck(master, 0);
+	bitbang_spi_set_mosi(master, 0);
+	/* FIXME: Release SPI bus here and request it again for each command or
+	 * don't release it now and only release it on programmer shutdown?
+	 */
+	bitbang_spi_release_bus(master);
 	return 0;
 }
 
-int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
-{
-	if (!bitbang_spi_master) {
-		msg_perr("Shutting down an uninitialized SPI bitbang master!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-	if (master != bitbang_spi_master) {
-		msg_perr("Shutting down a mismatched SPI bitbang master!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-
-	/* FIXME: Run bitbang_spi_release_bus here or per command? */
-	bitbang_spi_master = NULL;
-	return 0;
-}
-
-static uint8_t bitbang_spi_readwrite_byte(uint8_t val)
+static uint8_t bitbang_spi_rw_byte(const struct bitbang_spi_master *master,
+				   uint8_t val)
 {
 	uint8_t ret = 0;
 	int i;
 
 	for (i = 7; i >= 0; i--) {
-		bitbang_spi_set_mosi((val >> i) & 1);
-		programmer_delay(bitbang_spi_half_period);
-		bitbang_spi_set_sck(1);
+		bitbang_spi_set_mosi(master, (val >> i) & 1);
+		programmer_delay(master->half_period);
+		bitbang_spi_set_sck(master, 1);
 		ret <<= 1;
-		ret |= bitbang_spi_get_miso();
-		programmer_delay(bitbang_spi_half_period);
-		bitbang_spi_set_sck(0);
+		ret |= bitbang_spi_get_miso(master);
+		programmer_delay(master->half_period);
+		bitbang_spi_set_sck(master, 0);
 	}
 	return ret;
 }
@@ -149,23 +136,24 @@
 				    unsigned char *readarr)
 {
 	int i;
+	const struct bitbang_spi_master *master = flash->pgm->spi.data;
 
 	/* FIXME: Run bitbang_spi_request_bus here or in programmer init?
 	 * Requesting and releasing the SPI bus is handled in here to allow the
 	 * programmer to use its own SPI engine for native accesses.
 	 */
-	bitbang_spi_request_bus();
-	bitbang_spi_set_cs(0);
+	bitbang_spi_request_bus(master);
+	bitbang_spi_set_cs(master, 0);
 	for (i = 0; i < writecnt; i++)
-		bitbang_spi_readwrite_byte(writearr[i]);
+		bitbang_spi_rw_byte(master, writearr[i]);
 	for (i = 0; i < readcnt; i++)
-		readarr[i] = bitbang_spi_readwrite_byte(0);
+		readarr[i] = bitbang_spi_rw_byte(master, 0);
 
-	programmer_delay(bitbang_spi_half_period);
-	bitbang_spi_set_cs(1);
-	programmer_delay(bitbang_spi_half_period);
+	programmer_delay(master->half_period);
+	bitbang_spi_set_cs(master, 1);
+	programmer_delay(master->half_period);
 	/* FIXME: Run bitbang_spi_release_bus here or in programmer init? */
-	bitbang_spi_release_bus();
+	bitbang_spi_release_bus(master);
 
 	return 0;
 }
diff --git a/cli_classic.c b/cli_classic.c
index bb8c29f..543b644 100644
--- a/cli_classic.c
+++ b/cli_classic.c
@@ -172,7 +172,7 @@
 	struct flashctx flashes[3];
 	struct flashctx *fill_flash;
 	const char *name;
-	int namelen, opt, i;
+	int namelen, opt, i, j;
 	int startchip = 0, chipcount = 0, option_index = 0, force = 0;
 #if CONFIG_PRINT_WIKI == 1
 	int list_supported_wiki = 0;
@@ -444,17 +444,21 @@
 		ret = 1;
 		goto out_shutdown;
 	}
-	tempstr = flashbuses_to_text(buses_supported);
-	msg_pdbg("This programmer supports the following protocols: %s.\n",
+	tempstr = flashbuses_to_text(get_buses_supported());
+	msg_pdbg("The following protocols are supported: %s.\n",
 		 tempstr);
 	free(tempstr);
 
-	for (i = 0; i < ARRAY_SIZE(flashes); i++) {
-		startchip = probe_flash(startchip, &flashes[i], 0);
-		if (startchip == -1)
-			break;
-		chipcount++;
-		startchip++;
+	for (j = 0; j < registered_programmer_count; j++) {
+		startchip = 0;
+		for (i = 0; i < ARRAY_SIZE(flashes); i++) {
+			startchip = probe_flash(&registered_programmers[j],
+						startchip, &flashes[i], 0);
+			if (startchip == -1)
+				break;
+			chipcount++;
+			startchip++;
+		}
 	}
 
 	if (chipcount > 1) {
@@ -472,6 +476,7 @@
 			printf("Note: flashrom can never write if the flash "
 			       "chip isn't found automatically.\n");
 		}
+#if 0 // FIXME: What happens for a forced chip read if multiple compatible programmers are registered?
 		if (force && read_it && chip_to_probe) {
 			printf("Force read (-f -r -c) requested, pretending "
 			       "the chip is there:\n");
@@ -486,6 +491,7 @@
 			       "contain garbage.\n");
 			return read_flash_to_file(&flashes[0], filename);
 		}
+#endif
 		ret = 1;
 		goto out_shutdown;
 	} else if (!chip_to_probe) {
@@ -502,7 +508,7 @@
 	check_chip_supported(fill_flash);
 
 	size = fill_flash->total_size * 1024;
-	if (check_max_decode((buses_supported & fill_flash->bustype), size) &&
+	if (check_max_decode(fill_flash->pgm->buses_supported & fill_flash->bustype, size) &&
 	    (!force)) {
 		fprintf(stderr, "Chip is too big for this programmer "
 			"(-V gives details). Use --force to override.\n");
diff --git a/flash.h b/flash.h
index 29ba193..e21a986 100644
--- a/flash.h
+++ b/flash.h
@@ -171,6 +171,7 @@
 	chipaddr virtual_memory;
 	/* Some flash devices have an additional register space. */
 	chipaddr virtual_registers;
+	struct registered_programmer *pgm;
 };
 
 #define TEST_UNTESTED	0
@@ -224,14 +225,13 @@
 	write_gran_1byte,
 	write_gran_256bytes,
 };
-extern enum chipbustype buses_supported;
 extern int verbose;
 extern const char flashrom_version[];
 extern char *chip_to_probe;
 void map_flash_registers(struct flashctx *flash);
 int read_memmapped(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int erase_flash(struct flashctx *flash);
-int probe_flash(int startchip, struct flashctx *fill_flash, int force);
+int probe_flash(struct registered_programmer *pgm, int startchip, struct flashctx *fill_flash, int force);
 int read_flash_to_file(struct flashctx *flash, const char *filename);
 int min(int a, int b);
 int max(int a, int b);
@@ -256,6 +256,13 @@
 
 /* Something happened that shouldn't happen, we'll abort. */
 #define ERROR_FATAL -0xee
+#define ERROR_FLASHROM_BUG -200
+/* We reached one of the hardcoded limits of flashrom. This can be fixed by
+ * increasing the limit of a compile-time allocation or by switching to dynamic
+ * allocation.
+ * Note: If this warning is triggered, check first for runaway registrations.
+ */
+#define ERROR_FLASHROM_LIMIT -201
 
 /* cli_output.c */
 /* Let gcc and clang check for correct printf-style format strings. */
@@ -297,4 +304,5 @@
 int spi_send_multicommand(struct flashctx *flash, struct spi_command *cmds);
 uint32_t spi_get_valid_read_addr(struct flashctx *flash);
 
+enum chipbustype get_buses_supported(void);
 #endif				/* !__FLASH_H__ */
diff --git a/flashrom.c b/flashrom.c
index f7a17d1..f1a6165 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -46,9 +46,6 @@
 
 static char *programmer_param = NULL;
 
-/* Supported buses for the current programmer. */
-enum chipbustype buses_supported;
-
 /*
  * Programmers supporting multiple buses can have differing size limits on
  * each bus. Store the limits for each bus in a common struct.
@@ -314,7 +311,6 @@
 		.fwh		= 0xffffffff,
 		.spi		= 0xffffffff,
 	};
-	buses_supported = BUS_NONE;
 	/* Default to top aligned flash at 4 GB. */
 	flashbase = 0;
 	/* Registering shutdown functions is now allowed. */
@@ -361,44 +357,44 @@
 
 void chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr)
 {
-	par_programmer->chip_writeb(flash, val, addr);
+	flash->pgm->par.chip_writeb(flash, val, addr);
 }
 
 void chip_writew(const struct flashctx *flash, uint16_t val, chipaddr addr)
 {
-	par_programmer->chip_writew(flash, val, addr);
+	flash->pgm->par.chip_writew(flash, val, addr);
 }
 
 void chip_writel(const struct flashctx *flash, uint32_t val, chipaddr addr)
 {
-	par_programmer->chip_writel(flash, val, addr);
+	flash->pgm->par.chip_writel(flash, val, addr);
 }
 
 void chip_writen(const struct flashctx *flash, uint8_t *buf, chipaddr addr,
 		 size_t len)
 {
-	par_programmer->chip_writen(flash, buf, addr, len);
+	flash->pgm->par.chip_writen(flash, buf, addr, len);
 }
 
 uint8_t chip_readb(const struct flashctx *flash, const chipaddr addr)
 {
-	return par_programmer->chip_readb(flash, addr);
+	return flash->pgm->par.chip_readb(flash, addr);
 }
 
 uint16_t chip_readw(const struct flashctx *flash, const chipaddr addr)
 {
-	return par_programmer->chip_readw(flash, addr);
+	return flash->pgm->par.chip_readw(flash, addr);
 }
 
 uint32_t chip_readl(const struct flashctx *flash, const chipaddr addr)
 {
-	return par_programmer->chip_readl(flash, addr);
+	return flash->pgm->par.chip_readl(flash, addr);
 }
 
 void chip_readn(const struct flashctx *flash, uint8_t *buf, chipaddr addr,
 		size_t len)
 {
-	par_programmer->chip_readn(flash, buf, addr, len);
+	flash->pgm->par.chip_readn(flash, buf, addr, len);
 }
 
 void programmer_delay(int usecs)
@@ -942,7 +938,8 @@
 	return 1;
 }
 
-int probe_flash(int startchip, struct flashctx *fill_flash, int force)
+int probe_flash(struct registered_programmer *pgm, int startchip,
+		struct flashctx *fill_flash, int force)
 {
 	const struct flashchip *flash;
 	unsigned long base = 0;
@@ -954,20 +951,9 @@
 	for (flash = flashchips + startchip; flash && flash->name; flash++) {
 		if (chip_to_probe && strcmp(flash->name, chip_to_probe) != 0)
 			continue;
-		buses_common = buses_supported & flash->bustype;
-		if (!buses_common) {
-			msg_gspew("Probing for %s %s, %d kB: skipped. ",
-			         flash->vendor, flash->name, flash->total_size);
-			tmp = flashbuses_to_text(buses_supported);
-			msg_gspew("Host bus type %s ", tmp);
-			free(tmp);
-			tmp = flashbuses_to_text(flash->bustype);
-			msg_gspew("and chip bus type %s are incompatible.",
-				  tmp);
-			free(tmp);
-			msg_gspew("\n");
+		buses_common = pgm->buses_supported & flash->bustype;
+		if (!buses_common)
 			continue;
-		}
 		msg_gdbg("Probing for %s %s, %d kB: ",
 			     flash->vendor, flash->name, flash->total_size);
 		if (!flash->probe && !force) {
@@ -981,6 +967,7 @@
 
 		/* Start filling in the dynamic data. */
 		memcpy(fill_flash, flash, sizeof(struct flashchip));
+		fill_flash->pgm = pgm;
 
 		base = flashbase ? flashbase : (0xffffffff - size + 1);
 		fill_flash->virtual_memory = (chipaddr)programmer_map_flash_region("flash chip", base, size);
diff --git a/ichspi.c b/ichspi.c
index 6bcea45..163ecf1 100644
--- a/ichspi.c
+++ b/ichspi.c
@@ -635,7 +635,7 @@
 
 /* Read len bytes from the fdata/spid register into the data array.
  *
- * Note that using len > spi_programmer->max_data_read will return garbage or
+ * Note that using len > flash->pgm->spi.max_data_read will return garbage or
  * may even crash.
  */
 static void ich_read_data(uint8_t *data, int len, int reg0_off)
@@ -653,7 +653,7 @@
 
 /* Fill len bytes from the data array into the fdata/spid registers.
  *
- * Note that using len > spi_programmer->max_data_write will trash the registers
+ * Note that using len > flash->pgm->spi.max_data_write will trash the registers
  * following the data registers.
  */
 static void ich_fill_data(const uint8_t *data, int len, int reg0_off)
@@ -960,9 +960,9 @@
 		      uint8_t datalength, uint8_t * data)
 {
 	/* max_data_read == max_data_write for all Intel/VIA SPI masters */
-	uint8_t maxlength = spi_programmer->max_data_read;
+	uint8_t maxlength = flash->pgm->spi.max_data_read;
 
-	if (spi_programmer->type == SPI_CONTROLLER_NONE) {
+	if (ich_generation == CHIPSET_ICH_UNKNOWN) {
 		msg_perr("%s: unsupported chipset\n", __func__);
 		return -1;
 	}
@@ -1297,7 +1297,7 @@
 	REGWRITE16(ICH9_REG_HSFS, REGREAD16(ICH9_REG_HSFS));
 
 	while (len > 0) {
-		block_len = min(len, opaque_programmer->max_data_read);
+		block_len = min(len, flash->pgm->opaque.max_data_read);
 		ich_hwseq_set_addr(addr);
 		hsfc = REGREAD16(ICH9_REG_HSFC);
 		hsfc &= ~HSFC_FCYCLE; /* set read operation */
@@ -1336,7 +1336,7 @@
 
 	while (len > 0) {
 		ich_hwseq_set_addr(addr);
-		block_len = min(len, opaque_programmer->max_data_write);
+		block_len = min(len, flash->pgm->opaque.max_data_write);
 		ich_fill_data(buf, block_len, ICH9_REG_FDATA0);
 		hsfc = REGREAD16(ICH9_REG_HSFC);
 		hsfc &= ~HSFC_FCYCLE; /* clear operation */
diff --git a/mcp6x_spi.c b/mcp6x_spi.c
index d2c31be..23f39a5 100644
--- a/mcp6x_spi.c
+++ b/mcp6x_spi.c
@@ -98,6 +98,7 @@
 	.get_miso = mcp6x_bitbang_get_miso,
 	.request_bus = mcp6x_request_spibus,
 	.release_bus = mcp6x_release_spibus,
+	.half_period = 0,
 };
 
 int mcp6x_spi_init(int want_spi)
@@ -159,8 +160,7 @@
 		 (status >> MCP6X_SPI_GRANT) & 0x1);
 	mcp_gpiostate = status & 0xff;
 
-	/* Zero halfperiod delay. */
-	if (bitbang_spi_init(&bitbang_spi_master_mcp6x, 0)) {
+	if (bitbang_spi_init(&bitbang_spi_master_mcp6x)) {
 		/* This should never happen. */
 		msg_perr("MCP6X bitbang SPI master init failed!\n");
 		return 1;
diff --git a/nicintel_spi.c b/nicintel_spi.c
index aacd68c..f9432ec 100644
--- a/nicintel_spi.c
+++ b/nicintel_spi.c
@@ -137,6 +137,7 @@
 	.get_miso = nicintel_bitbang_get_miso,
 	.request_bus = nicintel_request_spibus,
 	.release_bus = nicintel_release_spibus,
+	.half_period = 1,
 };
 
 static int nicintel_spi_shutdown(void *data)
@@ -181,8 +182,7 @@
 	if (register_shutdown(nicintel_spi_shutdown, NULL))
 		return 1;
 
-	/* 1 usec halfperiod delay for now. */
-	if (bitbang_spi_init(&bitbang_spi_master_nicintel, 1))
+	if (bitbang_spi_init(&bitbang_spi_master_nicintel))
 		return 1;
 
 	return 0;
diff --git a/ogp_spi.c b/ogp_spi.c
index dbaa57a..812420c 100644
--- a/ogp_spi.c
+++ b/ogp_spi.c
@@ -91,6 +91,7 @@
 	.get_miso = ogp_bitbang_get_miso,
 	.request_bus = ogp_request_spibus,
 	.release_bus = ogp_release_spibus,
+	.half_period = 0,
 };
 
 static int ogp_spi_shutdown(void *data)
@@ -136,8 +137,7 @@
 	if (register_shutdown(ogp_spi_shutdown, NULL))
 		return 1;
 
-	/* no delay for now. */
-	if (bitbang_spi_init(&bitbang_spi_master_ogp, 0))
+	if (bitbang_spi_init(&bitbang_spi_master_ogp))
 		return 1;
 
 	return 0;
diff --git a/opaque.c b/opaque.c
index 43ddb07..6acaa63 100644
--- a/opaque.c
+++ b/opaque.c
@@ -30,70 +30,37 @@
 #include "chipdrivers.h"
 #include "programmer.h"
 
-const struct opaque_programmer opaque_programmer_none = {
-	.max_data_read = MAX_DATA_UNSPECIFIED,
-	.max_data_write = MAX_DATA_UNSPECIFIED,
-	.probe = NULL,
-	.read = NULL,
-	.write = NULL,
-	.erase = NULL,
-};
-
-const struct opaque_programmer *opaque_programmer = &opaque_programmer_none;
-
 int probe_opaque(struct flashctx *flash)
 {
-	if (!opaque_programmer->probe) {
-		msg_perr("%s called before register_opaque_programmer. "
-			 "Please report a bug at flashrom@flashrom.org\n",
-			 __func__);
-		return 0;
-	}
-
-	return opaque_programmer->probe(flash);
+	return flash->pgm->opaque.probe(flash);
 }
 
 int read_opaque(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len)
 {
-	if (!opaque_programmer->read) {
-		msg_perr("%s called before register_opaque_programmer. "
-			 "Please report a bug at flashrom@flashrom.org\n",
-			 __func__);
-		return 1;
-	}
-	return opaque_programmer->read(flash, buf, start, len);
+	return flash->pgm->opaque.read(flash, buf, start, len);
 }
 
 int write_opaque(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len)
 {
-	if (!opaque_programmer->write) {
-		msg_perr("%s called before register_opaque_programmer. "
-			 "Please report a bug at flashrom@flashrom.org\n",
-			 __func__);
-		return 1;
-	}
-	return opaque_programmer->write(flash, buf, start, len);
+	return flash->pgm->opaque.write(flash, buf, start, len);
 }
 
 int erase_opaque(struct flashctx *flash, unsigned int blockaddr, unsigned int blocklen)
 {
-	if (!opaque_programmer->erase) {
-		msg_perr("%s called before register_opaque_programmer. "
-			 "Please report a bug at flashrom@flashrom.org\n",
-			 __func__);
-		return 1;
-	}
-	return opaque_programmer->erase(flash, blockaddr, blocklen);
+	return flash->pgm->opaque.erase(flash, blockaddr, blocklen);
 }
 
-void register_opaque_programmer(const struct opaque_programmer *pgm)
+int register_opaque_programmer(const struct opaque_programmer *pgm)
 {
+	struct registered_programmer rpgm;
+
 	if (!pgm->probe || !pgm->read || !pgm->write || !pgm->erase) {
-		msg_perr("%s called with one of probe/read/write/erase being "
-			 "NULL. Please report a bug at flashrom@flashrom.org\n",
+		msg_perr("%s called with incomplete programmer definition. "
+			 "Please report a bug at flashrom@flashrom.org\n",
 			 __func__);
-		return;
+		return ERROR_FLASHROM_BUG;
 	}
-	opaque_programmer = pgm;
-	buses_supported |= BUS_PROG;
+	rpgm.buses_supported = BUS_PROG;
+	rpgm.opaque = *pgm;
+	return register_programmer(&rpgm);
 }
diff --git a/programmer.c b/programmer.c
index 2928d68..3b4def0 100644
--- a/programmer.c
+++ b/programmer.c
@@ -21,19 +21,6 @@
 #include "flash.h"
 #include "programmer.h"
 
-static const struct par_programmer par_programmer_none = {
-		.chip_readb		= noop_chip_readb,
-		.chip_readw		= fallback_chip_readw,
-		.chip_readl		= fallback_chip_readl,
-		.chip_readn		= fallback_chip_readn,
-		.chip_writeb		= noop_chip_writeb,
-		.chip_writew		= fallback_chip_writew,
-		.chip_writel		= fallback_chip_writel,
-		.chip_writen		= fallback_chip_writen,
-};
-
-const struct par_programmer *par_programmer = &par_programmer_none;
-
 /* No-op shutdown() for programmers which don't need special handling */
 int noop_shutdown(void)
 {
@@ -52,13 +39,7 @@
 {
 }
 
-/* No-op chip_writeb() for drivers not supporting addr/data pair accesses */
-uint8_t noop_chip_readb(const struct flashctx *flash, const chipaddr addr)
-{
-	return 0xff;
-}
-
-/* No-op chip_writeb() for drivers not supporting addr/data pair accesses */
+/* No-op chip_writeb() for parallel style drivers not supporting writes */
 void noop_chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr)
 {
 }
@@ -115,8 +96,50 @@
 	return;
 }
 
-void register_par_programmer(const struct par_programmer *pgm, const enum chipbustype buses)
+int register_par_programmer(const struct par_programmer *pgm,
+			    const enum chipbustype buses)
 {
-	par_programmer = pgm;
-	buses_supported |= buses;
+	struct registered_programmer rpgm;
+	if (!pgm->chip_writeb || !pgm->chip_writew || !pgm->chip_writel ||
+	    !pgm->chip_writen || !pgm->chip_readb || !pgm->chip_readw ||
+	    !pgm->chip_readl || !pgm->chip_readn) {
+		msg_perr("%s called with incomplete programmer definition. "
+			 "Please report a bug at flashrom@flashrom.org\n",
+			 __func__);
+		return ERROR_FLASHROM_BUG;
+	}
+
+	rpgm.buses_supported = buses;
+	rpgm.par = *pgm;
+	return register_programmer(&rpgm);
+}
+
+/* The limit of 4 is totally arbitrary. */
+#define PROGRAMMERS_MAX 4
+struct registered_programmer registered_programmers[PROGRAMMERS_MAX];
+int registered_programmer_count = 0;
+
+/* This function copies the struct registered_programmer parameter. */
+int register_programmer(struct registered_programmer *pgm)
+{
+	if (registered_programmer_count >= PROGRAMMERS_MAX) {
+		msg_perr("Tried to register more than %i programmer "
+			 "interfaces.\n", PROGRAMMERS_MAX);
+		return ERROR_FLASHROM_LIMIT;
+	}
+	registered_programmers[registered_programmer_count] = *pgm;
+	registered_programmer_count++;
+
+	return 0;
+}
+
+enum chipbustype get_buses_supported(void)
+{
+	int i;
+	enum chipbustype ret = BUS_NONE;
+
+	for (i = 0; i < registered_programmer_count; i++)
+		ret |= registered_programmers[i].buses_supported;
+
+	return ret;
 }
diff --git a/programmer.h b/programmer.h
index 9942686..a40d037 100644
--- a/programmer.h
+++ b/programmer.h
@@ -133,6 +133,8 @@
 	int (*get_miso) (void);
 	void (*request_bus) (void);
 	void (*release_bus) (void);
+	/* Length of half a clock period in usecs. */
+	unsigned int half_period;
 };
 
 #if CONFIG_INTERNAL == 1
@@ -208,6 +210,7 @@
 
 #if NEED_PCI == 1
 /* pcidev.c */
+// FIXME: These need to be local, not global
 extern uint32_t io_base_addr;
 extern struct pci_access *pacc;
 extern struct pci_dev *pcidev_dev;
@@ -427,8 +430,7 @@
 #endif
 
 /* bitbang_spi.c */
-int bitbang_spi_init(const struct bitbang_spi_master *master, int halfperiod);
-int bitbang_spi_shutdown(const struct bitbang_spi_master *master);
+int bitbang_spi_init(const struct bitbang_spi_master *master);
 
 /* buspirate_spi.c */
 #if CONFIG_BUSPIRATE_SPI == 1
@@ -452,6 +454,7 @@
 	uint32_t fwh;
 	uint32_t spi;
 };
+// FIXME: These need to be local, not global
 extern struct decode_sizes max_rom_decode;
 extern int programmer_may_write;
 extern unsigned long flashbase;
@@ -498,7 +501,6 @@
 	SPI_CONTROLLER_SERPROG,
 #endif
 };
-extern const int spi_programmer_count;
 
 #define MAX_DATA_UNSPECIFIED 0
 #define MAX_DATA_READ_UNLIMITED 64 * 1024
@@ -514,15 +516,15 @@
 	/* Optimized functions for this programmer */
 	int (*read)(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 	int (*write_256)(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
+	const void *data;
 };
 
-extern const struct spi_programmer *spi_programmer;
 int default_spi_send_command(struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
 			     const unsigned char *writearr, unsigned char *readarr);
 int default_spi_send_multicommand(struct flashctx *flash, struct spi_command *cmds);
 int default_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int default_spi_write_256(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
-void register_spi_programmer(const struct spi_programmer *programmer);
+int register_spi_programmer(const struct spi_programmer *programmer);
 
 /* ichspi.c */
 #if CONFIG_INTERNAL == 1
@@ -570,15 +572,14 @@
 	int (*read) (struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 	int (*write) (struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 	int (*erase) (struct flashctx *flash, unsigned int blockaddr, unsigned int blocklen);
+	const void *data;
 };
-extern const struct opaque_programmer *opaque_programmer;
-void register_opaque_programmer(const struct opaque_programmer *pgm);
+int register_opaque_programmer(const struct opaque_programmer *pgm);
 
 /* programmer.c */
 int noop_shutdown(void);
 void *fallback_map(const char *descr, unsigned long phys_addr, size_t len);
 void fallback_unmap(void *virt_addr, size_t len);
-uint8_t noop_chip_readb(const struct flashctx *flash, const chipaddr addr);
 void noop_chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr);
 void fallback_chip_writew(const struct flashctx *flash, uint16_t val, chipaddr addr);
 void fallback_chip_writel(const struct flashctx *flash, uint32_t val, chipaddr addr);
@@ -595,9 +596,20 @@
 	uint16_t (*chip_readw) (const struct flashctx *flash, const chipaddr addr);
 	uint32_t (*chip_readl) (const struct flashctx *flash, const chipaddr addr);
 	void (*chip_readn) (const struct flashctx *flash, uint8_t *buf, const chipaddr addr, size_t len);
+	const void *data;
 };
-extern const struct par_programmer *par_programmer;
-void register_par_programmer(const struct par_programmer *pgm, const enum chipbustype buses);
+int register_par_programmer(const struct par_programmer *pgm, const enum chipbustype buses);
+struct registered_programmer {
+	enum chipbustype buses_supported;
+	union {
+		struct par_programmer par;
+		struct spi_programmer spi;
+		struct opaque_programmer opaque;
+	};
+};
+extern struct registered_programmer registered_programmers[];
+extern int registered_programmer_count;
+int register_programmer(struct registered_programmer *pgm);
 
 /* serprog.c */
 #if CONFIG_SERPROG == 1
diff --git a/rayer_spi.c b/rayer_spi.c
index 417fde9..0011bc0 100644
--- a/rayer_spi.c
+++ b/rayer_spi.c
@@ -92,6 +92,7 @@
 	.set_sck = rayer_bitbang_set_sck,
 	.set_mosi = rayer_bitbang_set_mosi,
 	.get_miso = rayer_bitbang_get_miso,
+	.half_period = 0,
 };
 
 int rayer_spi_init(void)
@@ -171,8 +172,7 @@
 	/* Get the initial value before writing to any line. */
 	lpt_outbyte = INB(lpt_iobase);
 
-	/* Zero halfperiod delay. */
-	if (bitbang_spi_init(&bitbang_spi_master_rayer, 0))
+	if (bitbang_spi_init(&bitbang_spi_master_rayer))
 		return 1;
 
 	return 0;
diff --git a/spi.c b/spi.c
index 02c83f7..b2d3eb0 100644
--- a/spi.c
+++ b/spi.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the flashrom project.
  *
- * Copyright (C) 2007, 2008, 2009 Carl-Daniel Hailfinger
+ * Copyright (C) 2007, 2008, 2009, 2010, 2011 Carl-Daniel Hailfinger
  * Copyright (C) 2008 coresystems GmbH
  *
  * This program is free software; you can redistribute it and/or modify
@@ -30,43 +30,17 @@
 #include "programmer.h"
 #include "spi.h"
 
-const struct spi_programmer spi_programmer_none = {
-	.type = SPI_CONTROLLER_NONE,
-	.max_data_read = MAX_DATA_UNSPECIFIED,
-	.max_data_write = MAX_DATA_UNSPECIFIED,
-	.command = NULL,
-	.multicommand = NULL,
-	.read = NULL,
-	.write_256 = NULL,
-};
-
-const struct spi_programmer *spi_programmer = &spi_programmer_none;
-
 int spi_send_command(struct flashctx *flash, unsigned int writecnt,
 		     unsigned int readcnt, const unsigned char *writearr,
 		     unsigned char *readarr)
 {
-	if (!spi_programmer->command) {
-		msg_perr("%s called, but SPI is unsupported on this "
-			 "hardware. Please report a bug at "
-			 "flashrom@flashrom.org\n", __func__);
-		return 1;
-	}
-
-	return spi_programmer->command(flash, writecnt, readcnt, writearr,
+	return flash->pgm->spi.command(flash, writecnt, readcnt, writearr,
 				       readarr);
 }
 
 int spi_send_multicommand(struct flashctx *flash, struct spi_command *cmds)
 {
-	if (!spi_programmer->multicommand) {
-		msg_perr("%s called, but SPI is unsupported on this "
-			 "hardware. Please report a bug at "
-			 "flashrom@flashrom.org\n", __func__);
-		return 1;
-	}
-
-	return spi_programmer->multicommand(flash, cmds);
+	return flash->pgm->spi.multicommand(flash, cmds);
 }
 
 int default_spi_send_command(struct flashctx *flash, unsigned int writecnt,
@@ -104,7 +78,7 @@
 int default_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start,
 		     unsigned int len)
 {
-	unsigned int max_data = spi_programmer->max_data_read;
+	unsigned int max_data = flash->pgm->spi.max_data_read;
 	if (max_data == MAX_DATA_UNSPECIFIED) {
 		msg_perr("%s called, but SPI read chunk size not defined "
 			 "on this hardware. Please report a bug at "
@@ -117,7 +91,7 @@
 int default_spi_write_256(struct flashctx *flash, uint8_t *buf,
 			  unsigned int start, unsigned int len)
 {
-	unsigned int max_data = spi_programmer->max_data_write;
+	unsigned int max_data = flash->pgm->spi.max_data_write;
 	if (max_data == MAX_DATA_UNSPECIFIED) {
 		msg_perr("%s called, but SPI write chunk size not defined "
 			 "on this hardware. Please report a bug at "
@@ -131,12 +105,6 @@
 		  unsigned int len)
 {
 	unsigned int addrbase = 0;
-	if (!spi_programmer->read) {
-		msg_perr("%s called, but SPI read is unsupported on this "
-			 "hardware. Please report a bug at "
-			 "flashrom@flashrom.org\n", __func__);
-		return 1;
-	}
 
 	/* Check if the chip fits between lowest valid and highest possible
 	 * address. Highest possible address with the current SPI implementation
@@ -157,7 +125,7 @@
 			 "access window.\n");
 		msg_perr("Read will probably return garbage.\n");
 	}
-	return spi_programmer->read(flash, buf, addrbase + start, len);
+	return flash->pgm->spi.read(flash, buf, addrbase + start, len);
 }
 
 /*
@@ -170,14 +138,7 @@
 int spi_chip_write_256(struct flashctx *flash, uint8_t *buf, unsigned int start,
 		       unsigned int len)
 {
-	if (!spi_programmer->write_256) {
-		msg_perr("%s called, but SPI page write is unsupported on this "
-			 "hardware. Please report a bug at "
-			 "flashrom@flashrom.org\n", __func__);
-		return 1;
-	}
-
-	return spi_programmer->write_256(flash, buf, start, len);
+	return flash->pgm->spi.write_256(flash, buf, start, len);
 }
 
 /*
@@ -187,7 +148,7 @@
  */
 uint32_t spi_get_valid_read_addr(struct flashctx *flash)
 {
-	switch (spi_programmer->type) {
+	switch (flash->pgm->spi.type) {
 #if CONFIG_INTERNAL == 1
 #if defined(__i386__) || defined(__x86_64__)
 	case SPI_CONTROLLER_ICH7:
@@ -200,8 +161,22 @@
 	}
 }
 
-void register_spi_programmer(const struct spi_programmer *pgm)
+int register_spi_programmer(const struct spi_programmer *pgm)
 {
-	spi_programmer = pgm;
-	buses_supported |= BUS_SPI;
+	struct registered_programmer rpgm;
+
+	if (!pgm->write_256 || !pgm->read || !pgm->command ||
+	    !pgm->multicommand ||
+	    ((pgm->command == default_spi_send_command) &&
+	     (pgm->multicommand == default_spi_send_multicommand))) {
+		msg_perr("%s called with incomplete programmer definition. "
+			 "Please report a bug at flashrom@flashrom.org\n",
+			 __func__);
+		return ERROR_FLASHROM_BUG;
+	}
+
+
+	rpgm.buses_supported = BUS_SPI;
+	rpgm.spi = *pgm;
+	return register_programmer(&rpgm);
 }
diff --git a/spi25.c b/spi25.c
index 1e3bed9..3ce7f08 100644
--- a/spi25.c
+++ b/spi25.c
@@ -179,7 +179,7 @@
 	/* Some SPI controllers do not support commands with writecnt=1 and
 	 * readcnt=4.
 	 */
-	switch (spi_programmer->type) {
+	switch (flash->pgm->spi.type) {
 #if CONFIG_INTERNAL == 1
 #if defined(__i386__) || defined(__x86_64__)
 	case SPI_CONTROLLER_IT87XX:
@@ -1120,7 +1120,7 @@
 		.readarr	= NULL,
 	}};
 
-	switch (spi_programmer->type) {
+	switch (flash->pgm->spi.type) {
 #if CONFIG_INTERNAL == 1
 #if defined(__i386__) || defined(__x86_64__)
 	case SPI_CONTROLLER_IT87XX: