diff --git a/Makefile b/Makefile
index a645d4c..1991dc7 100644
--- a/Makefile
+++ b/Makefile
@@ -19,6 +19,10 @@
 LDFLAGS = -lpci -lz
 STRIP_ARGS = -s
 endif
+ifeq ($(OS_ARCH), FreeBSD)
+CFLAGS += -I/usr/local/include
+LDFLAGS += -L/usr/local/lib
+endif
 
 OBJS = chipset_enable.o board_enable.o udelay.o jedec.o stm50flw0x0x.c \
 	sst28sf040.o am29f040b.o mx29f002.o sst39sf020.o m29f400bt.o \
diff --git a/board_enable.c b/board_enable.c
index 9691748..06553e0 100644
--- a/board_enable.c
+++ b/board_enable.c
@@ -37,36 +37,36 @@
 /* Enter extended functions */
 static void w836xx_ext_enter(uint16_t port)
 {
-	outb(0x87, port);
-	outb(0x87, port);
+	OUTB(0x87, port);
+	OUTB(0x87, port);
 }
 
 /* Leave extended functions */
 static void w836xx_ext_leave(uint16_t port)
 {
-	outb(0xAA, port);
+	OUTB(0xAA, port);
 }
 
 /* General functions for reading/writing Winbond Super I/Os. */
 static unsigned char wbsio_read(uint16_t index, uint8_t reg)
 {
-	outb(reg, index);
-	return inb(index + 1);
+	OUTB(reg, index);
+	return INB(index + 1);
 }
 
 static void wbsio_write(uint16_t index, uint8_t reg, uint8_t data)
 {
-	outb(reg, index);
-	outb(data, index + 1);
+	OUTB(reg, index);
+	OUTB(data, index + 1);
 }
 
 static void wbsio_mask(uint16_t index, uint8_t reg, uint8_t data, uint8_t mask)
 {
 	uint8_t tmp;
 
-	outb(reg, index);
-	tmp = inb(index + 1) & ~mask;
-	outb(tmp | (data & mask), index + 1);
+	OUTB(reg, index);
+	tmp = INB(index + 1) & ~mask;
+	OUTB(tmp | (data & mask), index + 1);
 }
 
 /**
@@ -172,9 +172,9 @@
 	base = pci_read_word(dev, 0x88) & 0xFF80;
 
 	/* Enable GPIO15 which is connected to write protect. */
-	val = inb(base + 0x4D);
+	val = INB(base + 0x4D);
 	val |= 0x80;
-	outb(val, base + 0x4D);
+	OUTB(val, base + 0x4D);
 
 	return 0;
 }
@@ -249,14 +249,14 @@
 
 #define ASUSP5A_LOOP 5000
 
-	outb(0x00, 0xE807);
-	outb(0xEF, 0xE803);
+	OUTB(0x00, 0xE807);
+	OUTB(0xEF, 0xE803);
 
-	outb(0xFF, 0xE800);
+	OUTB(0xFF, 0xE800);
 
 	for (i = 0; i < ASUSP5A_LOOP; i++) {
-		outb(0xE1, 0xFF);
-		if (inb(0xE800) & 0x04)
+		OUTB(0xE1, 0xFF);
+		if (INB(0xE800) & 0x04)
 			break;
 	}
 
@@ -265,13 +265,13 @@
 		return -1;
 	}
 
-	outb(0x20, 0xE801);
-	outb(0x20, 0xE1);
+	OUTB(0x20, 0xE801);
+	OUTB(0x20, 0xE1);
 
-	outb(0xFF, 0xE802);
+	OUTB(0xFF, 0xE802);
 
 	for (i = 0; i < ASUSP5A_LOOP; i++) {
-		tmp = inb(0xE800);
+		tmp = INB(0xE800);
 		if (tmp & 0x70)
 			break;
 	}
@@ -281,24 +281,24 @@
 		return -1;
 	}
 
-	tmp = inb(0xE804);
+	tmp = INB(0xE804);
 	tmp &= ~0x02;
 
-	outb(0x00, 0xE807);
-	outb(0xEE, 0xE803);
+	OUTB(0x00, 0xE807);
+	OUTB(0xEE, 0xE803);
 
-	outb(tmp, 0xE804);
+	OUTB(tmp, 0xE804);
 
-	outb(0xFF, 0xE800);
-	outb(0xE1, 0xFF);
+	OUTB(0xFF, 0xE800);
+	OUTB(0xE1, 0xFF);
 
-	outb(0x20, 0xE801);
-	outb(0x20, 0xE1);
+	OUTB(0x20, 0xE801);
+	OUTB(0x20, 0xE1);
 
-	outb(0xFF, 0xE802);
+	OUTB(0xFF, 0xE802);
 
 	for (i = 0; i < ASUSP5A_LOOP; i++) {
-		tmp = inb(0xE800);
+		tmp = INB(0xE800);
 		if (tmp & 0x70)
 			break;
 	}
@@ -316,9 +316,9 @@
 	uint8_t byte;
 
 	/* Set GPIO lines in the Broadcom HT-1000 southbridge. */
-	outb(0x45, 0xcd6);
-	byte = inb(0xcd7);
-	outb(byte | 0x20, 0xcd7);
+	OUTB(0x45, 0xcd6);
+	byte = INB(0xcd7);
+	OUTB(byte | 0x20, 0xcd7);
 
 	return 0;
 }
@@ -331,13 +331,13 @@
 	uint8_t tmp;
 
 	/* Raise GPIO22. */
-	tmp = inb(0x4036);
-	outb(tmp, 0xEB);
+	tmp = INB(0x4036);
+	OUTB(tmp, 0xEB);
 
 	tmp |= 0x40;
 
-	outb(tmp, 0x4036);
-	outb(tmp, 0xEB);
+	OUTB(tmp, 0x4036);
+	OUTB(tmp, 0xEB);
 
 	return 0;
 }
@@ -360,10 +360,10 @@
 	/* Use GPIOBASE register to find where the GPIO is mapped. */
 	port = (pci_read_word(dev, 0x58) & 0xFFC0) + 0xE;
 
-	val = inb(port);
+	val = INB(port);
 	val |= 0x80; /* Top Block Lock -- pin 8 of PLCC32 */
 	val |= 0x40; /* Lower Blocks Lock -- pin 7 of PLCC32 */
-	outb(val, port);
+	OUTB(val, port);
 
 	return 0;
 }
@@ -449,7 +449,7 @@
 	/* Use GPIOBASE register to find where the GPIO is mapped. */
 	gpiobar = pci_read_word(dev, 0x48) & 0xfffc;
 
-	val = inl(gpiobar + ICH7_GPIO_LVL2);	/* GP_LVL2 */
+	val = INL(gpiobar + ICH7_GPIO_LVL2);	/* GP_LVL2 */
 	printf_debug("\nGPIOBAR=0x%04x GP_LVL: 0x%08x\n", gpiobar, val);
 
 	/* bit 2 (0x04) = 0 #TBL --> bootblock locking = 1
@@ -462,7 +462,7 @@
 	 */
 	val |= (1 << 2) | (1 << 3);
 
-	outl(val, gpiobar + ICH7_GPIO_LVL2);
+	OUTL(val, gpiobar + ICH7_GPIO_LVL2);
 
 	return 0;
 }
diff --git a/chipset_enable.c b/chipset_enable.c
index 8dca68f..1ab9a24 100644
--- a/chipset_enable.c
+++ b/chipset_enable.c
@@ -65,37 +65,37 @@
 	/* The same thing on SiS 950 Super I/O side... */
 
 	/* First probe for Super I/O on config port 0x2e. */
-	outb(0x87, 0x2e);
-	outb(0x01, 0x2e);
-	outb(0x55, 0x2e);
-	outb(0x55, 0x2e);
+	OUTB(0x87, 0x2e);
+	OUTB(0x01, 0x2e);
+	OUTB(0x55, 0x2e);
+	OUTB(0x55, 0x2e);
 
-	if (inb(0x2f) != 0x87) {
+	if (INB(0x2f) != 0x87) {
 		/* If that failed, try config port 0x4e. */
-		outb(0x87, 0x4e);
-		outb(0x01, 0x4e);
-		outb(0x55, 0x4e);
-		outb(0xaa, 0x4e);
-		if (inb(0x4f) != 0x87) {
+		OUTB(0x87, 0x4e);
+		OUTB(0x01, 0x4e);
+		OUTB(0x55, 0x4e);
+		OUTB(0xaa, 0x4e);
+		if (INB(0x4f) != 0x87) {
 			printf("Can not access SiS 950\n");
 			return -1;
 		}
-		outb(0x24, 0x4e);
-		b = inb(0x4f) | 0xfc;
-		outb(0x24, 0x4e);
-		outb(b, 0x4f);
-		outb(0x02, 0x4e);
-		outb(0x02, 0x4f);
+		OUTB(0x24, 0x4e);
+		b = INB(0x4f) | 0xfc;
+		OUTB(0x24, 0x4e);
+		OUTB(b, 0x4f);
+		OUTB(0x02, 0x4e);
+		OUTB(0x02, 0x4f);
 	}
 
-	outb(0x24, 0x2e);
-	printf("2f is %#x\n", inb(0x2f));
-	b = inb(0x2f) | 0xfc;
-	outb(0x24, 0x2e);
-	outb(b, 0x2f);
+	OUTB(0x24, 0x2e);
+	printf("2f is %#x\n", INB(0x2f));
+	b = INB(0x2f) | 0xfc;
+	OUTB(0x24, 0x2e);
+	OUTB(b, 0x2f);
 
-	outb(0x02, 0x2e);
-	outb(0x02, 0x2f);
+	OUTB(0x02, 0x2e);
+	OUTB(0x02, 0x2f);
 
 	return 0;
 }
@@ -522,13 +522,13 @@
 	pci_write_byte(dev, 0x48, tmp);
 
 	/* Now become a bit silly. */
-	tmp = inb(0xc6f);
-	outb(tmp, 0xeb);
-	outb(tmp, 0xeb);
+	tmp = INB(0xc6f);
+	OUTB(tmp, 0xeb);
+	OUTB(tmp, 0xeb);
 	tmp |= 0x40;
-	outb(tmp, 0xc6f);
-	outb(tmp, 0xeb);
-	outb(tmp, 0xeb);
+	OUTB(tmp, 0xc6f);
+	OUTB(tmp, 0xeb);
+	OUTB(tmp, 0xeb);
 
 	return 0;
 }
diff --git a/flash.h b/flash.h
index a3740ee..a41c660 100644
--- a/flash.h
+++ b/flash.h
@@ -30,6 +30,25 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#ifdef __FreeBSD__
+  #include <machine/cpufunc.h>
+  #define off64_t off_t
+  #define lseek64 lseek
+  #define OUTB(x, y) do { u_int tmp = (y); outb(tmp, (x)); } while (0)
+  #define OUTW(x, y) do { u_int tmp = (y); outw(tmp, (x)); } while (0)
+  #define OUTL(x, y) do { u_int tmp = (y); outl(tmp, (x)); } while (0)
+  #define INB(x) __extension__ ({ u_int tmp = (x); inb(tmp); })
+  #define INW(x) __extension__ ({ u_int tmp = (x); inw(tmp); })
+  #define INL(x) __extension__ ({ u_int tmp = (x); inl(tmp); })
+#else
+  #define OUTB outb
+  #define OUTW outw
+  #define OUTL outl
+  #define INB  inb
+  #define INW  inw
+  #define INL  inl
+#endif
+
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
 struct flashchip {
diff --git a/flashrom.c b/flashrom.c
index 842d473..e366f94 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -252,6 +252,9 @@
 	int option_index = 0;
 	int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0;
 	int ret = 0, i;
+#ifdef __FreeBSD__
+	int io_fd;
+#endif
 
 	static struct option long_options[] = {
 		{"read", 0, 0, 'r'},
@@ -367,6 +370,8 @@
 	/* First get full io access */
 #if defined (__sun) && (defined(__i386) || defined(__amd64))
 	if (sysi86(SI86V86, V86SC_IOPL, PS_IOPL) != 0) {
+#elif defined(__FreeBSD__)
+	if ((io_fd = open("/dev/io", O_RDWR)) < 0) {
 #else
 	if (iopl(3) != 0) {
 #endif
@@ -559,5 +564,8 @@
 	if (verify_it)
 		ret |= verify_flash(flash, buf);
 
+#ifdef __FreeBSD__
+	close(io_fd);
+#endif
 	return ret;
 }
diff --git a/it87spi.c b/it87spi.c
index 75010df..7e67892 100644
--- a/it87spi.c
+++ b/it87spi.c
@@ -40,14 +40,14 @@
 /* Generic Super I/O helper functions */
 uint8_t regval(uint16_t port, uint8_t reg)
 {
-	outb(reg, port);
-	return inb(port + 1);
+	OUTB(reg, port);
+	return INB(port + 1);
 }
 
 void regwrite(uint16_t port, uint8_t reg, uint8_t val)
 {
-	outb(reg, port);
-	outb(val, port + 1);
+	OUTB(reg, port);
+	OUTB(val, port + 1);
 }
 
 /* Helper functions for most recent ITE IT87xx Super I/O chips */
@@ -55,13 +55,13 @@
 #define CHIP_ID_BYTE2_REG	0x21
 static void enter_conf_mode_ite(uint16_t port)
 {
-	outb(0x87, port);
-	outb(0x01, port);
-	outb(0x55, port);
+	OUTB(0x87, port);
+	OUTB(0x01, port);
+	OUTB(0x55, port);
 	if (port == ITE_SUPERIO_PORT1)
-		outb(0x55, port);
+		OUTB(0x55, port);
 	else
-		outb(0xaa, port);
+		OUTB(0xaa, port);
 }
 
 static void exit_conf_mode_ite(uint16_t port)
@@ -129,7 +129,7 @@
 	int i;
 
 	do {
-		busy = inb(it8716f_flashport) & 0x80;
+		busy = INB(it8716f_flashport) & 0x80;
 	} while (busy);
 	if (readcnt > 3) {
 		printf("%s called with unsupported readcnt %i.\n",
@@ -138,27 +138,27 @@
 	}
 	switch (writecnt) {
 	case 1:
-		outb(writearr[0], it8716f_flashport + 1);
+		OUTB(writearr[0], it8716f_flashport + 1);
 		writeenc = 0x0;
 		break;
 	case 2:
-		outb(writearr[0], it8716f_flashport + 1);
-		outb(writearr[1], it8716f_flashport + 7);
+		OUTB(writearr[0], it8716f_flashport + 1);
+		OUTB(writearr[1], it8716f_flashport + 7);
 		writeenc = 0x1;
 		break;
 	case 4:
-		outb(writearr[0], it8716f_flashport + 1);
-		outb(writearr[1], it8716f_flashport + 4);
-		outb(writearr[2], it8716f_flashport + 3);
-		outb(writearr[3], it8716f_flashport + 2);
+		OUTB(writearr[0], it8716f_flashport + 1);
+		OUTB(writearr[1], it8716f_flashport + 4);
+		OUTB(writearr[2], it8716f_flashport + 3);
+		OUTB(writearr[3], it8716f_flashport + 2);
 		writeenc = 0x2;
 		break;
 	case 5:
-		outb(writearr[0], it8716f_flashport + 1);
-		outb(writearr[1], it8716f_flashport + 4);
-		outb(writearr[2], it8716f_flashport + 3);
-		outb(writearr[3], it8716f_flashport + 2);
-		outb(writearr[4], it8716f_flashport + 7);
+		OUTB(writearr[0], it8716f_flashport + 1);
+		OUTB(writearr[1], it8716f_flashport + 4);
+		OUTB(writearr[2], it8716f_flashport + 3);
+		OUTB(writearr[3], it8716f_flashport + 2);
+		OUTB(writearr[4], it8716f_flashport + 7);
 		writeenc = 0x3;
 		break;
 	default:
@@ -170,15 +170,15 @@
 	 * Note:
 	 * We can't use writecnt directly, but have to use a strange encoding.
 	 */ 
-	outb(((0x4 + (fast_spi ? 1 : 0)) << 4) | ((readcnt & 0x3) << 2) | (writeenc), it8716f_flashport);
+	OUTB(((0x4 + (fast_spi ? 1 : 0)) << 4) | ((readcnt & 0x3) << 2) | (writeenc), it8716f_flashport);
 
 	if (readcnt > 0) {
 		do {
-			busy = inb(it8716f_flashport) & 0x80;
+			busy = INB(it8716f_flashport) & 0x80;
 		} while (busy);
 
 		for (i = 0; i < readcnt; i++) {
-			readarr[i] = inb(it8716f_flashport + 5 + i);
+			readarr[i] = INB(it8716f_flashport + 5 + i);
 		}
 	}
 
@@ -190,12 +190,12 @@
 	int i;
 
 	spi_write_enable();
-	outb(0x06 , it8716f_flashport + 1);
-	outb(((2 + (fast_spi ? 1 : 0)) << 4), it8716f_flashport);
+	OUTB(0x06 , it8716f_flashport + 1);
+	OUTB(((2 + (fast_spi ? 1 : 0)) << 4), it8716f_flashport);
 	for (i = 0; i < 256; i++) {
 		bios[256 * block + i] = buf[256 * block + i];
 	}
-	outb(0, it8716f_flashport);
+	OUTB(0, it8716f_flashport);
 	/* Wait until the Write-In-Progress bit is cleared.
 	 * This usually takes 1-10 ms, so wait in 1 ms steps.
 	 */
@@ -221,7 +221,7 @@
 			myusec_delay(10);
 	}
 	/* resume normal ops... */
-	outb(0x20, it8716f_flashport);
+	OUTB(0x20, it8716f_flashport);
 	return 0;
 }