diff --git a/firmware/common/hackrf-ui.c b/firmware/common/hackrf-ui.c
index 8dd8715a..bca2e86a 100644
--- a/firmware/common/hackrf-ui.c
+++ b/firmware/common/hackrf-ui.c
@@ -60,17 +60,14 @@ static const hackrf_ui_t hackrf_ui_null = {
 	&hackrf_ui_set_antenna_bias_null,
 };
 
-const hackrf_ui_t* portapack_detect(void) __attribute__((weak));
-const hackrf_ui_t* rad1o_ui_setup(void) __attribute__((weak));
-
 static const hackrf_ui_t* ui = NULL;
 
 const hackrf_ui_t* hackrf_ui(void) {
 	/* Detect on first use. If no UI hardware is detected, use a stub function table. */
 	if( ui == NULL ) {
 #ifdef HACKRF_ONE
-		if( portapack_detect ) {
-			ui = portapack_detect();
+		if( portapack_hackrf_ui_init ) {
+			ui = portapack_hackrf_ui_init();
 		}
 #endif
 #ifdef RAD1O
diff --git a/firmware/common/hackrf_core.c b/firmware/common/hackrf_core.c
index 64254c5d..1ee7e3e6 100644
--- a/firmware/common/hackrf_core.c
+++ b/firmware/common/hackrf_core.c
@@ -39,6 +39,10 @@
 #include <libopencm3/lpc43xx/scu.h>
 #include <libopencm3/lpc43xx/ssp.h>
 
+#ifdef HACKRF_ONE
+#include "portapack.h"
+#endif
+
 #include "gpio_lpc.h"
 
 #define WAIT_CPU_CLOCK_INIT_DELAY   (10000)
@@ -712,6 +716,37 @@ void cpu_clock_init(void)
 #endif
 }
 
+void activate_best_clock_source(void)
+{
+#ifdef HACKRF_ONE
+	/* Ensure PortaPack reference oscillator is off while checking for external clock input. */
+	if( portapack_reference_oscillator && portapack()) {
+		portapack_reference_oscillator(false);
+	}
+#endif
+
+	/* Check for external clock input. */
+	if (si5351c_clkin_signal_valid(&clock_gen)) {
+		si5351c_set_clock_source(&clock_gen, PLL_SOURCE_CLKIN);
+	} else {
+#ifdef HACKRF_ONE
+		/* Enable PortaPack reference oscillator (if present), and check for valid clock. */
+		if( portapack_reference_oscillator && portapack() ) {
+			portapack_reference_oscillator(true);
+			delay(510000);	/* loop iterations @ 204MHz for >10ms for oscillator to enable. */
+			if (si5351c_clkin_signal_valid(&clock_gen)) {
+				si5351c_set_clock_source(&clock_gen, PLL_SOURCE_CLKIN);
+				return;
+			} else {
+				portapack_reference_oscillator(false);
+			}
+		}
+#endif
+		/* No external or PortaPack clock was found. Use HackRF Si5351C crystal. */
+		si5351c_set_clock_source(&clock_gen, PLL_SOURCE_XTAL);
+	}
+}
+
 void ssp1_set_mode_max2837(void)
 {
 	spi_bus_start(max2837.bus, &ssp_config_max2837);
diff --git a/firmware/common/hackrf_core.h b/firmware/common/hackrf_core.h
index 3b2f7982..e6e4e811 100644
--- a/firmware/common/hackrf_core.h
+++ b/firmware/common/hackrf_core.h
@@ -294,6 +294,8 @@ bool sample_rate_frac_set(uint32_t rate_num, uint32_t rate_denom);
 bool sample_rate_set(const uint32_t sampling_rate_hz);
 bool baseband_filter_bandwidth_set(const uint32_t bandwidth_hz);
 
+void activate_best_clock_source(void);
+
 #if (defined HACKRF_ONE || defined RAD1O)
 void enable_rf_power(void);
 void disable_rf_power(void);
diff --git a/firmware/common/portapack.c b/firmware/common/portapack.c
new file mode 100644
index 00000000..2931ff80
--- /dev/null
+++ b/firmware/common/portapack.c
@@ -0,0 +1,577 @@
+/*
+ * Copyright 2018 Jared Boone
+ *
+ * This file is part of HackRF.
+ *
+ * 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; either version 2, or (at your option)
+ * any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "portapack.h"
+
+#include "hackrf_core.h"
+#include "gpio_lpc.h"
+
+#include <libopencm3/lpc43xx/scu.h>
+
+static void portapack_sleep_milliseconds(const uint32_t milliseconds) {
+	/* NOTE: Naively assumes 204 MHz instruction cycle clock and five instructions per count */
+	delay(milliseconds * 40800);	
+}
+
+static struct gpio_t gpio_io_stbx = GPIO(5,  0);	/* P2_0 */
+static struct gpio_t gpio_addr    = GPIO(5,  1);	/* P2_1 */
+__attribute__((unused)) static struct gpio_t gpio_lcd_te  = GPIO(5,  3);	/* P2_3 */
+__attribute__((unused)) static struct gpio_t gpio_unused  = GPIO(5,  7);	/* P2_8 */
+static struct gpio_t gpio_lcd_rdx = GPIO(5,  4);	/* P2_4 */
+static struct gpio_t gpio_lcd_wrx = GPIO(1, 10);	/* P2_9 */
+static struct gpio_t gpio_dir     = GPIO(1, 13);	/* P2_13 */
+
+typedef struct portapack_if_t {
+	gpio_t gpio_dir;
+	gpio_t gpio_lcd_rdx;
+	gpio_t gpio_lcd_wrx;
+	gpio_t gpio_io_stbx;
+	gpio_t gpio_addr;
+	gpio_port_t* const gpio_port_data;
+	uint8_t io_reg;
+} portapack_if_t;
+
+static portapack_if_t portapack_if = {
+	.gpio_dir        = &gpio_dir,
+	.gpio_lcd_rdx    = &gpio_lcd_rdx,
+	.gpio_lcd_wrx    = &gpio_lcd_wrx,
+	.gpio_io_stbx    = &gpio_io_stbx,
+	.gpio_addr       = &gpio_addr,
+	.gpio_port_data  = GPIO_LPC_PORT(3),
+	.io_reg          = 0x03,
+};
+
+/* NOTE: Code below assumes the shift value is "8". */
+#define GPIO_DATA_SHIFT (8)
+static const uint32_t gpio_data_mask = 0xFFU << GPIO_DATA_SHIFT;
+
+static void portapack_data_mask_set() {
+	portapack_if.gpio_port_data->mask = ~gpio_data_mask;
+}
+
+static void portapack_data_write_low(const uint32_t value) {
+	portapack_if.gpio_port_data->mpin = (value << GPIO_DATA_SHIFT);
+}
+
+static void portapack_data_write_high(const uint32_t value) {
+	/* NOTE: Assumes no other bits in the port are masked. */
+	/* NOTE: Assumes that bits 15 through 8 are masked. */
+	portapack_if.gpio_port_data->mpin = value;
+}
+
+static void portapack_dir_read() {
+	portapack_if.gpio_port_data->dir &= ~gpio_data_mask;
+	gpio_set(portapack_if.gpio_dir);
+}
+
+static void portapack_dir_write() {
+	gpio_clear(portapack_if.gpio_dir);
+	portapack_if.gpio_port_data->dir |= gpio_data_mask;
+	/* TODO: Manipulating DIR[3] makes me queasy. The RFFC5072 DATA pin
+	 * is also on port 3, and switches direction periodically...
+	 * Time to resort to bit-banding to enforce atomicity? But then, how
+	 * to change direction on eight bits efficiently? Or do I care, since
+	 * the PortaPack data bus shouldn't change direction too frequently?
+	 */
+}
+
+__attribute__((unused)) static void portapack_lcd_rd_assert() {
+	gpio_clear(portapack_if.gpio_lcd_rdx);
+}
+
+static void portapack_lcd_rd_deassert() {
+	gpio_set(portapack_if.gpio_lcd_rdx);
+}
+
+static void portapack_lcd_wr_assert() {
+	gpio_clear(portapack_if.gpio_lcd_wrx);
+}
+
+static void portapack_lcd_wr_deassert() {
+	gpio_set(portapack_if.gpio_lcd_wrx);
+}
+
+static void portapack_io_stb_assert() {
+	gpio_clear(portapack_if.gpio_io_stbx);
+}
+
+static void portapack_io_stb_deassert() {
+	gpio_set(portapack_if.gpio_io_stbx);
+}
+
+static void portapack_addr(const bool value) {
+	gpio_write(portapack_if.gpio_addr, value);
+}
+
+static void portapack_lcd_command(const uint32_t value) {
+	portapack_data_write_high(0);		/* Drive high byte (with zero -- don't care) */
+	portapack_dir_write();			/* Turn around data bus, MCU->CPLD */
+	portapack_addr(0);				/* Indicate command */
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	portapack_lcd_wr_assert();		/* Latch high byte */
+
+	portapack_data_write_low(value);	/* Drive low byte (pass-through) */
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	portapack_lcd_wr_deassert();		/* Complete write operation */
+
+	portapack_addr(1);				/* Set up for data phase (most likely after a command) */
+}
+
+static void portapack_lcd_write_data(const uint32_t value) {
+	// NOTE: Assumes and DIR=0 and ADDR=1 from command phase.
+	portapack_data_write_high(value);	/* Drive high byte */
+	__asm__("nop");
+	portapack_lcd_wr_assert();		/* Latch high byte */
+
+	portapack_data_write_low(value);	/* Drive low byte (pass-through) */
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	portapack_lcd_wr_deassert();		/* Complete write operation */
+}
+
+static void portapack_io_write(const bool address, const uint_fast16_t value) {
+	portapack_data_write_low(value);
+	portapack_dir_write();
+	portapack_addr(address);
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	portapack_io_stb_assert();
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	portapack_io_stb_deassert();
+}
+
+static void portapack_if_init() {
+	portapack_data_mask_set();
+	portapack_data_write_high(0);
+
+	portapack_dir_read();
+	portapack_lcd_rd_deassert();
+	portapack_lcd_wr_deassert();
+	portapack_io_stb_deassert();
+	portapack_addr(0);
+
+	gpio_output(portapack_if.gpio_dir);
+	gpio_output(portapack_if.gpio_lcd_rdx);
+	gpio_output(portapack_if.gpio_lcd_wrx);
+	gpio_output(portapack_if.gpio_io_stbx);
+	gpio_output(portapack_if.gpio_addr);
+	/* gpio_input(portapack_if.gpio_rot_a); */
+	/* gpio_input(portapack_if.gpio_rot_b); */
+
+	scu_pinmux(SCU_PINMUX_PP_D0, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D1, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D2, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D3, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D4, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D5, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D6, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+	scu_pinmux(SCU_PINMUX_PP_D7, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
+
+	scu_pinmux(SCU_PINMUX_PP_DIR,     SCU_CONF_FUNCTION0 | SCU_GPIO_NOPULL);
+	scu_pinmux(SCU_PINMUX_PP_LCD_RDX, SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
+	scu_pinmux(SCU_PINMUX_PP_LCD_WRX, SCU_CONF_FUNCTION0 | SCU_GPIO_NOPULL);
+	scu_pinmux(SCU_PINMUX_PP_IO_STBX, SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
+	scu_pinmux(SCU_PINMUX_PP_ADDR,    SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
+	/* scu_pinmux(SCU_PINMUX_PP_LCD_TE,   SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL); */
+	/* scu_pinmux(SCU_PINMUX_PP_UNUSED,   SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL); */
+}
+
+static void portapack_lcd_reset_state(const bool active) {
+	portapack_if.io_reg = (portapack_if.io_reg & 0xfe) | (active ? (1 << 0) : 0);
+	portapack_io_write(1, portapack_if.io_reg);
+}
+
+static void portapack_lcd_data_write_command_and_data(
+	const uint_fast8_t command,
+	const uint8_t* data,
+	const size_t data_count
+) {
+	portapack_lcd_command(command);
+	for(size_t i=0; i<data_count; i++) {
+		portapack_lcd_write_data(data[i]);
+	}
+}
+
+static void portapack_lcd_sleep_out() {
+	const uint8_t cmd_11[] = {};
+	portapack_lcd_data_write_command_and_data(0x11, cmd_11, ARRAY_SIZEOF(cmd_11));
+	// "It will be necessary to wait 120msec after sending Sleep Out
+	// command (when in Sleep In Mode) before Sleep In command can be
+	// sent."
+	portapack_sleep_milliseconds(120);
+}
+
+static void portapack_lcd_display_on() {
+	const uint8_t cmd_29[] = {};
+	portapack_lcd_data_write_command_and_data(0x29, cmd_29, ARRAY_SIZEOF(cmd_29));
+}
+
+static void portapack_lcd_ramwr_start() {
+	const uint8_t cmd_2c[] = {};
+	portapack_lcd_data_write_command_and_data(0x2c, cmd_2c, ARRAY_SIZEOF(cmd_2c));
+}
+
+static void portapack_lcd_set(const uint_fast8_t command, const uint_fast16_t start, const uint_fast16_t end) {
+	const uint8_t data[] = {
+		(start >> 8), (start & 0xff),
+		(end   >> 8), (end   & 0xff)
+	};
+	portapack_lcd_data_write_command_and_data(command, data, ARRAY_SIZEOF(data));
+}
+
+static void portapack_lcd_caset(const uint_fast16_t start_column, const uint_fast16_t end_column) {
+	portapack_lcd_set(0x2a, start_column, end_column);
+}
+
+static void portapack_lcd_paset(const uint_fast16_t start_page, const uint_fast16_t end_page) {
+	portapack_lcd_set(0x2b, start_page, end_page);
+}
+
+static void portapack_lcd_start_ram_write(
+	const ui_rect_t rect
+) {
+	portapack_lcd_caset(rect.point.x, rect.point.x + rect.size.width  - 1);
+	portapack_lcd_paset(rect.point.y, rect.point.y + rect.size.height - 1);
+	portapack_lcd_ramwr_start();
+}
+
+static void portapack_lcd_write_pixel(const ui_color_t pixel) {
+	portapack_lcd_write_data(pixel.v);
+}
+
+static void portapack_lcd_write_pixels_color(const ui_color_t c, size_t n) {
+	while(n--) {
+		portapack_lcd_write_data(c.v);
+	}
+}
+
+static void portapack_lcd_wake() {
+	portapack_lcd_sleep_out();
+	portapack_lcd_display_on();
+}
+
+static void portapack_lcd_reset() {
+	portapack_lcd_reset_state(false);
+	portapack_sleep_milliseconds(1);
+	portapack_lcd_reset_state(true);
+	portapack_sleep_milliseconds(10);
+	portapack_lcd_reset_state(false);
+	portapack_sleep_milliseconds(120);
+}
+
+static void portapack_lcd_init() {
+	// LCDs are configured for IM[2:0] = 001
+	// 8080-I system, 16-bit parallel bus
+
+	//
+	// 0x3a: DBI[2:0] = 101
+	// MDT[1:0] = XX (if not in 18-bit mode, right?)
+
+	// Power control B
+	// 0
+	// PCEQ=1, DRV_ena=0, Power control=3
+	const uint8_t cmd_cf[] = { 0x00, 0xD9, 0x30 };
+	portapack_lcd_data_write_command_and_data(0xCF, cmd_cf, ARRAY_SIZEOF(cmd_cf));
+
+	// Power on sequence control
+	const uint8_t cmd_ed[] = { 0x64, 0x03, 0x12, 0x81 };
+	portapack_lcd_data_write_command_and_data(0xED, cmd_ed, ARRAY_SIZEOF(cmd_ed));
+
+	// Driver timing control A
+	const uint8_t cmd_e8[] = { 0x85, 0x10, 0x78 };
+	portapack_lcd_data_write_command_and_data(0xE8, cmd_e8, ARRAY_SIZEOF(cmd_e8));
+
+	// Power control A
+	const uint8_t cmd_cb[] = { 0x39, 0x2C, 0x00, 0x34, 0x02 };
+	portapack_lcd_data_write_command_and_data(0xCB, cmd_cb, ARRAY_SIZEOF(cmd_cb));
+
+	// Pump ratio control
+	const uint8_t cmd_f7[] = { 0x20 };
+	portapack_lcd_data_write_command_and_data(0xF7, cmd_f7, ARRAY_SIZEOF(cmd_f7));
+
+	// Driver timing control B
+	const uint8_t cmd_ea[] = { 0x00, 0x00 };
+	portapack_lcd_data_write_command_and_data(0xEA, cmd_ea, ARRAY_SIZEOF(cmd_ea));
+
+	const uint8_t cmd_b1[] = { 0x00, 0x1B };
+	portapack_lcd_data_write_command_and_data(0xB1, cmd_b1, ARRAY_SIZEOF(cmd_b1));
+
+	// Blanking Porch Control
+	// VFP = 0b0000010 = 2 (number of HSYNC of vertical front porch)
+	// VBP = 0b0000010 = 2 (number of HSYNC of vertical back porch)
+	// HFP = 0b0001010 = 10 (number of DOTCLOCK of horizontal front porch)
+	// HBP = 0b0010100 = 20 (number of DOTCLOCK of horizontal back porch)
+	const uint8_t cmd_b5[] = { 0x02, 0x02, 0x0a, 0x14 };
+	portapack_lcd_data_write_command_and_data(0xB5, cmd_b5, ARRAY_SIZEOF(cmd_b5));
+
+	// Display Function Control
+	// PT[1:0] = 0b10
+	// PTG[1:0] = 0b10
+	// ISC[3:0] = 0b0010 (scan cycle interval of gate driver: 5 frames)
+	// SM = 0 (gate driver pin arrangement in combination with GS)
+	// SS = 1 (source output scan direction S720 -> S1)
+	// GS = 0 (gate output scan direction G1 -> G320)
+	// REV = 1 (normally white)
+	// NL = 0b100111 (default)
+	// PCDIV = 0b000000 (default?)
+	const uint8_t cmd_b6[] = { 0x0A, 0xA2, 0x27, 0x00 };
+	portapack_lcd_data_write_command_and_data(0xB6, cmd_b6, ARRAY_SIZEOF(cmd_b6));
+
+	// Power Control 1
+	//VRH[5:0]
+	const uint8_t cmd_c0[] = { 0x1B };
+	portapack_lcd_data_write_command_and_data(0xC0, cmd_c0, ARRAY_SIZEOF(cmd_c0));
+
+	// Power Control 2
+	//SAP[2:0];BT[3:0]
+	const uint8_t cmd_c1[] = { 0x12 };
+	portapack_lcd_data_write_command_and_data(0xC1, cmd_c1, ARRAY_SIZEOF(cmd_c1));
+
+	// VCOM Control 1
+	const uint8_t cmd_c5[] = { 0x32, 0x3C };
+	portapack_lcd_data_write_command_and_data(0xC5, cmd_c5, ARRAY_SIZEOF(cmd_c5));
+
+	// VCOM Control 2
+	const uint8_t cmd_c7[] = { 0x9B };
+	portapack_lcd_data_write_command_and_data(0xC7, cmd_c7, ARRAY_SIZEOF(cmd_c7));
+
+	// Memory Access Control
+	// Invert X and Y memory access order, so upper-left of
+	// screen is (0,0) when writing to display.
+	const uint8_t cmd_36[] = {
+		(1 << 7) |	// MY=1
+		(1 << 6) |	// MX=1
+		(0 << 5) |	// MV=0
+		(1 << 4) |	// ML=1: reverse vertical refresh to simplify scrolling logic
+		(1 << 3)	// BGR=1: For Kingtech LCD, BGR filter.
+	};
+	portapack_lcd_data_write_command_and_data(0x36, cmd_36, ARRAY_SIZEOF(cmd_36));
+
+	// COLMOD: Pixel Format Set
+	// DPI=101 (16 bits/pixel), DBI=101 (16 bits/pixel)
+	const uint8_t cmd_3a[] = { 0x55 };
+	portapack_lcd_data_write_command_and_data(0x3A, cmd_3a, ARRAY_SIZEOF(cmd_3a));
+
+	//portapack_lcd_data_write_command_and_data(0xF6, { 0x01, 0x30 });
+	// WEMODE=1 (reset column and page number on overflow)
+	// MDT[1:0]
+	// EPF[1:0]=00 (use channel MSB for LSB)
+	// RIM=0 (If COLMOD[6:4]=101 (65k color), 16-bit RGB interface (1 transfer/pixel))
+	// RM=0 (system interface/VSYNC interface)
+	// DM[1:0]=00 (internal clock operation)
+	// ENDIAN=0 (doesn't matter with 16-bit interface)
+	const uint8_t cmd_f6[] = { 0x01, 0x30, 0x00 };
+	portapack_lcd_data_write_command_and_data(0xF6, cmd_f6, ARRAY_SIZEOF(cmd_f6));
+
+	// 3Gamma Function Disable
+	const uint8_t cmd_f2[] = { 0x00 };
+	portapack_lcd_data_write_command_and_data(0xF2, cmd_f2, ARRAY_SIZEOF(cmd_f2));
+
+	// Gamma curve selected
+	const uint8_t cmd_26[] = { 0x01 };
+	portapack_lcd_data_write_command_and_data(0x26, cmd_26, ARRAY_SIZEOF(cmd_26));
+
+	// Set Gamma
+	const uint8_t cmd_e0[] = {
+		0x0F, 0x1D, 0x19, 0x0E, 0x10, 0x07, 0x4C, 0x63,
+		0x3F, 0x03, 0x0D, 0x00, 0x26, 0x24, 0x04
+	};
+	portapack_lcd_data_write_command_and_data(0xE0, cmd_e0, ARRAY_SIZEOF(cmd_e0));
+
+	// Set Gamma
+	const uint8_t cmd_e1[] = {
+		0x00, 0x1C, 0x1F, 0x02, 0x0F, 0x03, 0x35, 0x25,
+		0x47, 0x04, 0x0C, 0x0B, 0x29, 0x2F, 0x05
+	};
+	portapack_lcd_data_write_command_and_data(0xE1, cmd_e1, ARRAY_SIZEOF(cmd_e1));
+
+	portapack_lcd_wake();
+
+	// Turn on Tearing Effect Line (TE) output signal.
+	const uint8_t cmd_35[] = { 0b00000000 };
+	portapack_lcd_data_write_command_and_data(0x35, cmd_35, ARRAY_SIZEOF(cmd_35));
+}
+
+void portapack_backlight(const bool on) {
+	portapack_if.io_reg = (portapack_if.io_reg & 0x7f) | (on ? (1 << 7) : 0);
+	portapack_io_write(1, portapack_if.io_reg);
+}
+
+void portapack_reference_oscillator(const bool on) {
+	const uint8_t mask = 1 << 6;
+	portapack_if.io_reg = (portapack_if.io_reg & ~mask) | (on ? mask : 0);
+	portapack_io_write(1, portapack_if.io_reg);
+}
+
+void portapack_fill_rectangle(
+	const ui_rect_t rect,
+	const ui_color_t color
+) {
+	portapack_lcd_start_ram_write(rect);
+	portapack_lcd_write_pixels_color(color, rect.size.width * rect.size.height);
+}
+
+void portapack_clear_display(const ui_color_t color) {
+	const ui_rect_t rect_screen = { { 0, 0 }, { 240, 320 } };
+	portapack_fill_rectangle(rect_screen, color);
+}
+
+void portapack_draw_bitmap(
+	const ui_point_t point,
+	const ui_bitmap_t bitmap,
+	const ui_color_t foreground,
+	const ui_color_t background
+) {
+	const ui_rect_t rect = {
+		.point = point,
+		.size = bitmap.size
+	};
+
+	portapack_lcd_start_ram_write(rect);
+
+	const size_t count = bitmap.size.width * bitmap.size.height;
+	for(size_t i=0; i<count; i++) {
+		const uint8_t pixel = bitmap.data[i >> 3] & (1U << (i & 0x7));
+		portapack_lcd_write_pixel(pixel ? foreground : background);
+	}
+}
+
+ui_bitmap_t portapack_font_glyph(
+	const ui_font_t* const font,
+	const char c
+) {
+	if( c >= font->c_start ) {
+		const uint_fast8_t index = c - font->c_start;
+		if( index < font->c_count ) {
+			const ui_bitmap_t bitmap = {
+				.size = font->glyph_size,
+				.data = &font->data[index * font->data_stride]
+			};
+			return bitmap;
+		}
+	}
+
+	const ui_bitmap_t bitmap = {
+		.size = font->glyph_size,
+		.data = font->data,
+	};
+	return bitmap;
+}
+
+static bool jtag_pp_tck(const bool tms_value) {
+	gpio_write(jtag_cpld.gpio->gpio_pp_tms, tms_value);
+
+	// 8 ns TMS/TDI to TCK setup
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+
+	gpio_set(jtag_cpld.gpio->gpio_tck);
+
+	// 15 ns TCK to TMS/TDI hold time
+	// 20 ns TCK high time
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+
+	gpio_clear(jtag_cpld.gpio->gpio_tck);
+
+	// 20 ns TCK low time
+	// 25 ns TCK falling edge to TDO valid
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+	__asm__("nop");
+
+	return gpio_read(jtag_cpld.gpio->gpio_pp_tdo);
+}
+
+static uint32_t jtag_pp_shift(const uint32_t tms_bits, const size_t count) {
+	uint32_t result = 0;
+	size_t bit_in_index = count - 1;
+	size_t bit_out_index = 0;
+	while(bit_out_index < count) {
+		const uint32_t tdo = jtag_pp_tck((tms_bits >> bit_in_index) & 1) & 1;
+		result |= (tdo << bit_out_index);
+
+		bit_in_index--;
+		bit_out_index++;
+	}
+
+	return result;
+}
+
+static uint32_t jtag_pp_idcode(void) {
+	cpld_jtag_take(&jtag_cpld);
+
+	/* TODO: Check if PortaPack TMS is floating or driven by an external device. */
+	gpio_output(jtag_cpld.gpio->gpio_pp_tms);
+
+	/* Test-Logic/Reset -> Run-Test/Idle -> Select-DR/Scan -> Capture-DR */
+	jtag_pp_shift(0b11111010, 8);
+
+	/* Shift-DR */
+	const uint32_t idcode = jtag_pp_shift(0, 32);
+
+	/* Exit1-DR -> Update-DR -> Run-Test/Idle -> ... -> Test-Logic/Reset */
+	jtag_pp_shift(0b11011111, 8);
+
+	cpld_jtag_release(&jtag_cpld);
+
+	return idcode;
+}
+
+static bool portapack_detect(void) {
+	return jtag_pp_idcode() == 0x020A50DD;
+}
+
+static const portapack_t portapack_instance = {
+};
+
+static const portapack_t* portapack_pointer = NULL;
+
+const portapack_t* portapack(void) {
+	return portapack_pointer;
+}
+
+void portapack_init(void) {
+	if( portapack_detect() ) {
+		portapack_if_init();
+		portapack_lcd_reset();
+		portapack_lcd_init();
+		portapack_pointer = &portapack_instance;
+	} else {
+		portapack_pointer = NULL;
+	}
+}
\ No newline at end of file
diff --git a/firmware/common/portapack.h b/firmware/common/portapack.h
new file mode 100644
index 00000000..98f682f2
--- /dev/null
+++ b/firmware/common/portapack.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2018 Jared Boone
+ *
+ * This file is part of HackRF.
+ *
+ * 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; either version 2, or (at your option)
+ * any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __PORTAPACK_H__
+#define __PORTAPACK_H__
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#define ARRAY_SIZEOF(x) (sizeof(x) / sizeof(x[0]))
+
+typedef struct ui_color_t {
+	uint16_t v;
+} ui_color_t;
+
+typedef struct ui_point_t {
+	int16_t x;
+	int16_t y;
+} ui_point_t;
+
+typedef struct ui_size_t {
+	int16_t width;
+	int16_t height;
+} ui_size_t;
+
+typedef struct ui_rect_t {
+	ui_point_t point;
+	ui_size_t size;
+} ui_rect_t;
+
+typedef struct ui_bitmap_t {
+	ui_size_t size;
+	const uint8_t* const data;
+} ui_bitmap_t;
+
+typedef struct ui_font_t {
+	const ui_size_t glyph_size;
+	const uint8_t* const data;
+	char c_start;
+	size_t c_count;
+	size_t data_stride;
+} ui_font_t;
+
+typedef struct portapack_t {
+} portapack_t;
+
+void portapack_init(void);
+
+/* If the "portapack" symbol is defined, PortaPack support is compiled in */
+/* If the portapack() call returns non-NULL, a PortaPack was detected and is initialized. */
+const portapack_t* portapack(void) __attribute__((weak));
+
+void portapack_backlight(const bool on);
+
+void portapack_reference_oscillator(const bool on) __attribute__((weak));
+
+void portapack_fill_rectangle(
+	const ui_rect_t rect,
+	const ui_color_t color
+);
+
+void portapack_clear_display(const ui_color_t color);
+
+void portapack_draw_bitmap(
+	const ui_point_t point,
+	const ui_bitmap_t bitmap,
+	const ui_color_t foreground,
+	const ui_color_t background
+);
+
+ui_bitmap_t portapack_font_glyph(
+	const ui_font_t* const font,
+	const char c
+);
+
+#endif/*__PORTAPACK_H__*/
diff --git a/firmware/common/si5351c.c b/firmware/common/si5351c.c
index 64a3dda1..a7364241 100644
--- a/firmware/common/si5351c.c
+++ b/firmware/common/si5351c.c
@@ -22,7 +22,7 @@
 
 #include "si5351c.h"
 
-enum pll_sources active_clock_source;
+enum pll_sources active_clock_source = PLL_SOURCE_UNINITIALIZED;
 
 /* write to single register */
 void si5351c_write_single(si5351c_driver_t* const drv, uint8_t reg, uint8_t val)
@@ -239,25 +239,14 @@ void si5351c_set_int_mode(si5351c_driver_t* const drv, const uint_fast8_t ms_num
 
 void si5351c_set_clock_source(si5351c_driver_t* const drv, const enum pll_sources source)
 {
-	si5351c_configure_clock_control(drv, source);
-	active_clock_source = source;
+	if( source != active_clock_source ) {
+		si5351c_configure_clock_control(drv, source);
+		active_clock_source = source;
+	}
 }
 
-void si5351c_activate_best_clock_source(si5351c_driver_t* const drv)
-{
-	uint8_t device_status = si5351c_read_single(drv, 0);
-
-	if (device_status & SI5351C_LOS) {
-		/* CLKIN not detected */
-		if (active_clock_source == PLL_SOURCE_CLKIN) {
-			si5351c_set_clock_source(drv, PLL_SOURCE_XTAL);
-		}
-	} else {
-		/* CLKIN detected */
-		if (active_clock_source == PLL_SOURCE_XTAL) {
-			si5351c_set_clock_source(drv, PLL_SOURCE_CLKIN);
-		}
-	}
+bool si5351c_clkin_signal_valid(si5351c_driver_t* const drv) {
+	return (si5351c_read_single(drv, 0) & SI5351C_LOS) == 0;
 }
 
 void si5351c_clkout_enable(si5351c_driver_t* const drv, uint8_t enable)
diff --git a/firmware/common/si5351c.h b/firmware/common/si5351c.h
index 533c5830..03e82260 100644
--- a/firmware/common/si5351c.h
+++ b/firmware/common/si5351c.h
@@ -29,6 +29,7 @@ extern "C"
 #endif
 
 #include <stdint.h>
+#include <stdbool.h>
 
 #include "i2c_bus.h"
 
@@ -59,6 +60,7 @@ extern "C"
 #define SI5351C_LOS (1<<4)
 
 enum pll_sources {
+	PLL_SOURCE_UNINITIALIZED = -1,
 	PLL_SOURCE_XTAL = 0,
 	PLL_SOURCE_CLKIN = 1,
 };
@@ -84,7 +86,7 @@ void si5351c_configure_clock_control(si5351c_driver_t* const drv, const enum pll
 void si5351c_enable_clock_outputs(si5351c_driver_t* const drv);
 void si5351c_set_int_mode(si5351c_driver_t* const drv, const uint_fast8_t ms_number, const uint_fast8_t on);
 void si5351c_set_clock_source(si5351c_driver_t* const drv, const enum pll_sources source);
-void si5351c_activate_best_clock_source(si5351c_driver_t* const drv);
+bool si5351c_clkin_signal_valid(si5351c_driver_t* const drv);
 
 void si5351c_write_single(si5351c_driver_t* const drv, uint8_t reg, uint8_t val);
 uint8_t si5351c_read_single(si5351c_driver_t* const drv, uint8_t reg);
diff --git a/firmware/common/ui_portapack.c b/firmware/common/ui_portapack.c
index e8430af1..a61c3b5a 100644
--- a/firmware/common/ui_portapack.c
+++ b/firmware/common/ui_portapack.c
@@ -19,16 +19,9 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#include "hackrf-ui.h"
-
 #include "ui_portapack.h"
 
-#include "hackrf_core.h"
-#include "gpio_lpc.h"
-
-#include <libopencm3/lpc43xx/scu.h>
-
-#include <stddef.h>
+#include "portapack.h"
 
 /* Pixel data within a font or bitmap byte is "reversed": LSB is left-most pixel. */
 
@@ -263,524 +256,6 @@ __attribute__((unused)) static ui_color_t portapack_color_rgb(
 static const ui_color_t color_background = { 0x001f };
 static const ui_color_t color_foreground = { 0xffff };
 
-#define ARRAY_SIZEOF(x) (sizeof(x) / sizeof(x[0]))
-
-static void portapack_sleep_milliseconds(const uint32_t milliseconds) {
-	/* NOTE: Naively assumes 204 MHz instruction cycle clock and five instructions per count */
-	delay(milliseconds * 40800);	
-}
-
-static struct gpio_t gpio_io_stbx = GPIO(5,  0);	/* P2_0 */
-static struct gpio_t gpio_addr    = GPIO(5,  1);	/* P2_1 */
-__attribute__((unused)) static struct gpio_t gpio_lcd_te  = GPIO(5,  3);	/* P2_3 */
-__attribute__((unused)) static struct gpio_t gpio_unused  = GPIO(5,  7);	/* P2_8 */
-static struct gpio_t gpio_lcd_rdx = GPIO(5,  4);	/* P2_4 */
-static struct gpio_t gpio_lcd_wrx = GPIO(1, 10);	/* P2_9 */
-static struct gpio_t gpio_dir     = GPIO(1, 13);	/* P2_13 */
-
-typedef struct portapack_t {
-	gpio_t gpio_dir;
-	gpio_t gpio_lcd_rdx;
-	gpio_t gpio_lcd_wrx;
-	gpio_t gpio_io_stbx;
-	gpio_t gpio_addr;
-	gpio_port_t* const gpio_port_data;
-	uint8_t io_reg;
-} portapack_t;
-
-static portapack_t portapack = {
-	.gpio_dir        = &gpio_dir,
-	.gpio_lcd_rdx    = &gpio_lcd_rdx,
-	.gpio_lcd_wrx    = &gpio_lcd_wrx,
-	.gpio_io_stbx    = &gpio_io_stbx,
-	.gpio_addr       = &gpio_addr,
-	.gpio_port_data  = GPIO_LPC_PORT(3),
-	.io_reg          = 0x03,
-};
-
-/* NOTE: Code below assumes the shift value is "8". */
-#define GPIO_DATA_SHIFT (8)
-static const uint32_t gpio_data_mask = 0xFFU << GPIO_DATA_SHIFT;
-
-static void portapack_data_mask_set() {
-	portapack.gpio_port_data->mask = ~gpio_data_mask;
-}
-
-static void portapack_data_write_low(const uint32_t value) {
-	portapack.gpio_port_data->mpin = (value << GPIO_DATA_SHIFT);
-}
-
-static void portapack_data_write_high(const uint32_t value) {
-	/* NOTE: Assumes no other bits in the port are masked. */
-	/* NOTE: Assumes that bits 15 through 8 are masked. */
-	portapack.gpio_port_data->mpin = value;
-}
-
-static void portapack_dir_read() {
-	portapack.gpio_port_data->dir &= ~gpio_data_mask;
-	gpio_set(portapack.gpio_dir);
-}
-
-static void portapack_dir_write() {
-	gpio_clear(portapack.gpio_dir);
-	portapack.gpio_port_data->dir |= gpio_data_mask;
-	/* TODO: Manipulating DIR[3] makes me queasy. The RFFC5072 DATA pin
-	 * is also on port 3, and switches direction periodically...
-	 * Time to resort to bit-banding to enforce atomicity? But then, how
-	 * to change direction on eight bits efficiently? Or do I care, since
-	 * the PortaPack data bus shouldn't change direction too frequently?
-	 */
-}
-
-__attribute__((unused)) static void portapack_lcd_rd_assert() {
-	gpio_clear(portapack.gpio_lcd_rdx);
-}
-
-static void portapack_lcd_rd_deassert() {
-	gpio_set(portapack.gpio_lcd_rdx);
-}
-
-static void portapack_lcd_wr_assert() {
-	gpio_clear(portapack.gpio_lcd_wrx);
-}
-
-static void portapack_lcd_wr_deassert() {
-	gpio_set(portapack.gpio_lcd_wrx);
-}
-
-static void portapack_io_stb_assert() {
-	gpio_clear(portapack.gpio_io_stbx);
-}
-
-static void portapack_io_stb_deassert() {
-	gpio_set(portapack.gpio_io_stbx);
-}
-
-static void portapack_addr(const bool value) {
-	gpio_write(portapack.gpio_addr, value);
-}
-
-static void portapack_lcd_command(const uint32_t value) {
-	portapack_data_write_high(0);		/* Drive high byte (with zero -- don't care) */
-	portapack_dir_write();			/* Turn around data bus, MCU->CPLD */
-	portapack_addr(0);				/* Indicate command */
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	portapack_lcd_wr_assert();		/* Latch high byte */
-
-	portapack_data_write_low(value);	/* Drive low byte (pass-through) */
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	portapack_lcd_wr_deassert();		/* Complete write operation */
-
-	portapack_addr(1);				/* Set up for data phase (most likely after a command) */
-}
-
-static void portapack_lcd_write_data(const uint32_t value) {
-	// NOTE: Assumes and DIR=0 and ADDR=1 from command phase.
-	portapack_data_write_high(value);	/* Drive high byte */
-	__asm__("nop");
-	portapack_lcd_wr_assert();		/* Latch high byte */
-
-	portapack_data_write_low(value);	/* Drive low byte (pass-through) */
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	portapack_lcd_wr_deassert();		/* Complete write operation */
-}
-
-static void portapack_io_write(const bool address, const uint_fast16_t value) {
-	portapack_data_write_low(value);
-	portapack_dir_write();
-	portapack_addr(address);
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	portapack_io_stb_assert();
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	portapack_io_stb_deassert();
-}
-
-static void portapack_lcd_data_write_command_and_data(
-	const uint_fast8_t command,
-	const uint8_t* data,
-	const size_t data_count
-) {
-	portapack_lcd_command(command);
-	for(size_t i=0; i<data_count; i++) {
-		portapack_lcd_write_data(data[i]);
-	}
-}
-
-static void portapack_lcd_write_pixel(const ui_color_t pixel) {
-	portapack_lcd_write_data(pixel.v);
-}
-
-static void portapack_lcd_write_pixels_color(ui_color_t c, size_t n) {
-	while(n--) {
-		portapack_lcd_write_data(c.v);
-	}
-}
-
-static void portapack_backlight(const bool on) {
-	portapack.io_reg = (portapack.io_reg & 0x7f) | (on ? (1 << 7) : 0);
-	portapack_io_write(1, portapack.io_reg);
-}
-
-static void portapack_lcd_reset_state(const bool active) {
-	portapack.io_reg = (portapack.io_reg & 0xfe) | (active ? (1 << 0) : 0);
-	portapack_io_write(1, portapack.io_reg);
-}
-
-static void portapack_lcd_sleep_out() {
-	const uint8_t cmd_11[] = {};
-	portapack_lcd_data_write_command_and_data(0x11, cmd_11, ARRAY_SIZEOF(cmd_11));
-	// "It will be necessary to wait 120msec after sending Sleep Out
-	// command (when in Sleep In Mode) before Sleep In command can be
-	// sent."
-	portapack_sleep_milliseconds(120);
-}
-
-static void portapack_lcd_display_on() {
-	const uint8_t cmd_29[] = {};
-	portapack_lcd_data_write_command_and_data(0x29, cmd_29, ARRAY_SIZEOF(cmd_29));
-}
-
-static void portapack_lcd_wake() {
-	portapack_lcd_sleep_out();
-	portapack_lcd_display_on();
-}
-
-static bool jtag_pp_tck(const bool tms_value) {
-	gpio_write(jtag_cpld.gpio->gpio_pp_tms, tms_value);
-
-	// 8 ns TMS/TDI to TCK setup
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-
-	gpio_set(jtag_cpld.gpio->gpio_tck);
-
-	// 15 ns TCK to TMS/TDI hold time
-	// 20 ns TCK high time
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-
-	gpio_clear(jtag_cpld.gpio->gpio_tck);
-
-	// 20 ns TCK low time
-	// 25 ns TCK falling edge to TDO valid
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-	__asm__("nop");
-
-	return gpio_read(jtag_cpld.gpio->gpio_pp_tdo);
-}
-
-static uint32_t jtag_pp_shift(const uint32_t tms_bits, const size_t count) {
-	uint32_t result = 0;
-	size_t bit_in_index = count - 1;
-	size_t bit_out_index = 0;
-	while(bit_out_index < count) {
-		const uint32_t tdo = jtag_pp_tck((tms_bits >> bit_in_index) & 1) & 1;
-		result |= (tdo << bit_out_index);
-
-		bit_in_index--;
-		bit_out_index++;
-	}
-
-	return result;
-}
-
-static uint32_t jtag_pp_idcode() {
-	cpld_jtag_take(&jtag_cpld);
-
-	/* TODO: Check if PortaPack TMS is floating or driven by an external device. */
-	gpio_output(jtag_cpld.gpio->gpio_pp_tms);
-
-	/* Test-Logic/Reset -> Run-Test/Idle -> Select-DR/Scan -> Capture-DR */
-	jtag_pp_shift(0b11111010, 8);
-
-	/* Shift-DR */
-	const uint32_t idcode = jtag_pp_shift(0, 32);
-
-	/* Exit1-DR -> Update-DR -> Run-Test/Idle -> ... -> Test-Logic/Reset */
-	jtag_pp_shift(0b11011111, 8);
-
-	cpld_jtag_release(&jtag_cpld);
-
-	return idcode;
-}
-
-static void portapack_if_init() {
-	portapack_data_mask_set();
-	portapack_data_write_high(0);
-
-	portapack_dir_read();
-	portapack_lcd_rd_deassert();
-	portapack_lcd_wr_deassert();
-	portapack_io_stb_deassert();
-	portapack_addr(0);
-
-	gpio_output(portapack.gpio_dir);
-	gpio_output(portapack.gpio_lcd_rdx);
-	gpio_output(portapack.gpio_lcd_wrx);
-	gpio_output(portapack.gpio_io_stbx);
-	gpio_output(portapack.gpio_addr);
-	/* gpio_input(portapack.gpio_rot_a); */
-	/* gpio_input(portapack.gpio_rot_b); */
-
-	scu_pinmux(SCU_PINMUX_PP_D0, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D1, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D2, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D3, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D4, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D5, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D6, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-	scu_pinmux(SCU_PINMUX_PP_D7, SCU_CONF_FUNCTION0 | SCU_GPIO_PDN);
-
-	scu_pinmux(SCU_PINMUX_PP_DIR,     SCU_CONF_FUNCTION0 | SCU_GPIO_NOPULL);
-	scu_pinmux(SCU_PINMUX_PP_LCD_RDX, SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
-	scu_pinmux(SCU_PINMUX_PP_LCD_WRX, SCU_CONF_FUNCTION0 | SCU_GPIO_NOPULL);
-	scu_pinmux(SCU_PINMUX_PP_IO_STBX, SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
-	scu_pinmux(SCU_PINMUX_PP_ADDR,    SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL);
-	/* scu_pinmux(SCU_PINMUX_PP_LCD_TE,   SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL); */
-	/* scu_pinmux(SCU_PINMUX_PP_UNUSED,   SCU_CONF_FUNCTION4 | SCU_GPIO_NOPULL); */
-}
-
-static void portapack_lcd_reset() {
-	portapack_lcd_reset_state(false);
-	portapack_sleep_milliseconds(1);
-	portapack_lcd_reset_state(true);
-	portapack_sleep_milliseconds(10);
-	portapack_lcd_reset_state(false);
-	portapack_sleep_milliseconds(120);
-}
-
-static void portapack_lcd_init() {
-	// LCDs are configured for IM[2:0] = 001
-	// 8080-I system, 16-bit parallel bus
-
-	//
-	// 0x3a: DBI[2:0] = 101
-	// MDT[1:0] = XX (if not in 18-bit mode, right?)
-
-	// Power control B
-	// 0
-	// PCEQ=1, DRV_ena=0, Power control=3
-	const uint8_t cmd_cf[] = { 0x00, 0xD9, 0x30 };
-	portapack_lcd_data_write_command_and_data(0xCF, cmd_cf, ARRAY_SIZEOF(cmd_cf));
-
-	// Power on sequence control
-	const uint8_t cmd_ed[] = { 0x64, 0x03, 0x12, 0x81 };
-	portapack_lcd_data_write_command_and_data(0xED, cmd_ed, ARRAY_SIZEOF(cmd_ed));
-
-	// Driver timing control A
-	const uint8_t cmd_e8[] = { 0x85, 0x10, 0x78 };
-	portapack_lcd_data_write_command_and_data(0xE8, cmd_e8, ARRAY_SIZEOF(cmd_e8));
-
-	// Power control A
-	const uint8_t cmd_cb[] = { 0x39, 0x2C, 0x00, 0x34, 0x02 };
-	portapack_lcd_data_write_command_and_data(0xCB, cmd_cb, ARRAY_SIZEOF(cmd_cb));
-
-	// Pump ratio control
-	const uint8_t cmd_f7[] = { 0x20 };
-	portapack_lcd_data_write_command_and_data(0xF7, cmd_f7, ARRAY_SIZEOF(cmd_f7));
-
-	// Driver timing control B
-	const uint8_t cmd_ea[] = { 0x00, 0x00 };
-	portapack_lcd_data_write_command_and_data(0xEA, cmd_ea, ARRAY_SIZEOF(cmd_ea));
-
-	const uint8_t cmd_b1[] = { 0x00, 0x1B };
-	portapack_lcd_data_write_command_and_data(0xB1, cmd_b1, ARRAY_SIZEOF(cmd_b1));
-
-	// Blanking Porch Control
-	// VFP = 0b0000010 = 2 (number of HSYNC of vertical front porch)
-	// VBP = 0b0000010 = 2 (number of HSYNC of vertical back porch)
-	// HFP = 0b0001010 = 10 (number of DOTCLOCK of horizontal front porch)
-	// HBP = 0b0010100 = 20 (number of DOTCLOCK of horizontal back porch)
-	const uint8_t cmd_b5[] = { 0x02, 0x02, 0x0a, 0x14 };
-	portapack_lcd_data_write_command_and_data(0xB5, cmd_b5, ARRAY_SIZEOF(cmd_b5));
-
-	// Display Function Control
-	// PT[1:0] = 0b10
-	// PTG[1:0] = 0b10
-	// ISC[3:0] = 0b0010 (scan cycle interval of gate driver: 5 frames)
-	// SM = 0 (gate driver pin arrangement in combination with GS)
-	// SS = 1 (source output scan direction S720 -> S1)
-	// GS = 0 (gate output scan direction G1 -> G320)
-	// REV = 1 (normally white)
-	// NL = 0b100111 (default)
-	// PCDIV = 0b000000 (default?)
-	const uint8_t cmd_b6[] = { 0x0A, 0xA2, 0x27, 0x00 };
-	portapack_lcd_data_write_command_and_data(0xB6, cmd_b6, ARRAY_SIZEOF(cmd_b6));
-
-	// Power Control 1
-	//VRH[5:0]
-	const uint8_t cmd_c0[] = { 0x1B };
-	portapack_lcd_data_write_command_and_data(0xC0, cmd_c0, ARRAY_SIZEOF(cmd_c0));
-
-	// Power Control 2
-	//SAP[2:0];BT[3:0]
-	const uint8_t cmd_c1[] = { 0x12 };
-	portapack_lcd_data_write_command_and_data(0xC1, cmd_c1, ARRAY_SIZEOF(cmd_c1));
-
-	// VCOM Control 1
-	const uint8_t cmd_c5[] = { 0x32, 0x3C };
-	portapack_lcd_data_write_command_and_data(0xC5, cmd_c5, ARRAY_SIZEOF(cmd_c5));
-
-	// VCOM Control 2
-	const uint8_t cmd_c7[] = { 0x9B };
-	portapack_lcd_data_write_command_and_data(0xC7, cmd_c7, ARRAY_SIZEOF(cmd_c7));
-
-	// Memory Access Control
-	// Invert X and Y memory access order, so upper-left of
-	// screen is (0,0) when writing to display.
-	const uint8_t cmd_36[] = {
-		(1 << 7) |	// MY=1
-		(1 << 6) |	// MX=1
-		(0 << 5) |	// MV=0
-		(1 << 4) |	// ML=1: reverse vertical refresh to simplify scrolling logic
-		(1 << 3)	// BGR=1: For Kingtech LCD, BGR filter.
-	};
-	portapack_lcd_data_write_command_and_data(0x36, cmd_36, ARRAY_SIZEOF(cmd_36));
-
-	// COLMOD: Pixel Format Set
-	// DPI=101 (16 bits/pixel), DBI=101 (16 bits/pixel)
-	const uint8_t cmd_3a[] = { 0x55 };
-	portapack_lcd_data_write_command_and_data(0x3A, cmd_3a, ARRAY_SIZEOF(cmd_3a));
-
-	//portapack_lcd_data_write_command_and_data(0xF6, { 0x01, 0x30 });
-	// WEMODE=1 (reset column and page number on overflow)
-	// MDT[1:0]
-	// EPF[1:0]=00 (use channel MSB for LSB)
-	// RIM=0 (If COLMOD[6:4]=101 (65k color), 16-bit RGB interface (1 transfer/pixel))
-	// RM=0 (system interface/VSYNC interface)
-	// DM[1:0]=00 (internal clock operation)
-	// ENDIAN=0 (doesn't matter with 16-bit interface)
-	const uint8_t cmd_f6[] = { 0x01, 0x30, 0x00 };
-	portapack_lcd_data_write_command_and_data(0xF6, cmd_f6, ARRAY_SIZEOF(cmd_f6));
-
-	// 3Gamma Function Disable
-	const uint8_t cmd_f2[] = { 0x00 };
-	portapack_lcd_data_write_command_and_data(0xF2, cmd_f2, ARRAY_SIZEOF(cmd_f2));
-
-	// Gamma curve selected
-	const uint8_t cmd_26[] = { 0x01 };
-	portapack_lcd_data_write_command_and_data(0x26, cmd_26, ARRAY_SIZEOF(cmd_26));
-
-	// Set Gamma
-	const uint8_t cmd_e0[] = {
-		0x0F, 0x1D, 0x19, 0x0E, 0x10, 0x07, 0x4C, 0x63,
-		0x3F, 0x03, 0x0D, 0x00, 0x26, 0x24, 0x04
-	};
-	portapack_lcd_data_write_command_and_data(0xE0, cmd_e0, ARRAY_SIZEOF(cmd_e0));
-
-	// Set Gamma
-	const uint8_t cmd_e1[] = {
-		0x00, 0x1C, 0x1F, 0x02, 0x0F, 0x03, 0x35, 0x25,
-		0x47, 0x04, 0x0C, 0x0B, 0x29, 0x2F, 0x05
-	};
-	portapack_lcd_data_write_command_and_data(0xE1, cmd_e1, ARRAY_SIZEOF(cmd_e1));
-
-	portapack_lcd_wake();
-
-	// Turn on Tearing Effect Line (TE) output signal.
-	const uint8_t cmd_35[] = { 0b00000000 };
-	portapack_lcd_data_write_command_and_data(0x35, cmd_35, ARRAY_SIZEOF(cmd_35));
-}
-
-static void portapack_lcd_ramwr_start() {
-	const uint8_t cmd_2c[] = {};
-	portapack_lcd_data_write_command_and_data(0x2c, cmd_2c, ARRAY_SIZEOF(cmd_2c));
-}
-
-static void portapack_lcd_set(const uint_fast8_t command, const uint_fast16_t start, const uint_fast16_t end) {
-	const uint8_t data[] = {
-		(start >> 8), (start & 0xff),
-		(end   >> 8), (end   & 0xff)
-	};
-	portapack_lcd_data_write_command_and_data(command, data, ARRAY_SIZEOF(data));
-}
-
-static void portapack_lcd_caset(const uint_fast16_t start_column, uint_fast16_t end_column) {
-	portapack_lcd_set(0x2a, start_column, end_column);
-}
-
-static void portapack_lcd_paset(const uint_fast16_t start_page, const uint_fast16_t end_page) {
-	portapack_lcd_set(0x2b, start_page, end_page);
-}
-
-
-static void portapack_lcd_start_ram_write(
-	ui_rect_t rect
-) {
-	portapack_lcd_caset(rect.point.x, rect.point.x + rect.size.width  - 1);
-	portapack_lcd_paset(rect.point.y, rect.point.y + rect.size.height - 1);
-	portapack_lcd_ramwr_start();
-}
-
-static void portapack_lcd_fill_rectangle(
-	ui_rect_t rect,
-	ui_color_t color
-) {
-	portapack_lcd_start_ram_write(rect);
-	portapack_lcd_write_pixels_color(color, rect.size.width * rect.size.height);
-}
-
-static void portapack_draw_bitmap(
-	const ui_point_t point,
-	const ui_bitmap_t bitmap,
-	const ui_color_t foreground,
-	const ui_color_t background
-) {
-	const ui_rect_t rect = {
-		.point = point,
-		.size = bitmap.size
-	};
-
-	portapack_lcd_start_ram_write(rect);
-
-	const size_t count = bitmap.size.width * bitmap.size.height;
-	for(size_t i=0; i<count; i++) {
-		const uint8_t pixel = bitmap.data[i >> 3] & (1U << (i & 0x7));
-		portapack_lcd_write_pixel(pixel ? foreground : background);
-	}
-}
-
-static ui_bitmap_t portapack_font_glyph(
-	const ui_font_t* const font,
-	const char c
-) {
-	if( c >= font->c_start ) {
-		const uint_fast8_t index = c - font->c_start;
-		if( index < font->c_count ) {
-			const ui_bitmap_t bitmap = {
-				.size = font->glyph_size,
-				.data = &font->data[index * font->data_stride]
-			};
-			return bitmap;
-		}
-	}
-
-	const ui_bitmap_t bitmap = {
-		.size = font->glyph_size,
-		.data = font->data,
-	};
-	return bitmap;
-}
-
 static ui_point_t portapack_lcd_draw_int(const ui_point_t point, uint64_t value, size_t field_width) {
 	const ui_point_t point_done = {
 		.x = point.x + font_fixed_8x16.glyph_size.width * field_width,
@@ -811,11 +286,6 @@ static ui_point_t portapack_lcd_draw_string(ui_point_t point, const char* s) {
 	return point;
 }
 
-static void portapack_lcd_clear() {
-	const ui_rect_t rect_screen = { { 0, 0 }, { 240, 320 } };
-	portapack_lcd_fill_rectangle(rect_screen, color_background);
-}
-
 typedef struct draw_list_t {
 	const ui_bitmap_t* bitmap;
 	const ui_point_t point;
@@ -888,12 +358,9 @@ static void portapack_radio_path_redraw() {
 	portapack_draw_radio_path(radio_draw_list, ARRAY_SIZEOF(radio_draw_list));
 }
 
-static void portapack_ui_init() {
-	portapack_if_init();
-	portapack_lcd_reset();
-	portapack_lcd_init();
-	portapack_lcd_clear();
-	portapack_backlight(1);
+static void portapack_ui_init(void) {
+	portapack_clear_display(color_background);
+	portapack_backlight(true);
 }
 
 static void portapack_ui_set_frequency(uint64_t frequency) {
@@ -914,7 +381,7 @@ static void portapack_ui_set_frequency(uint64_t frequency) {
 		if( (i>=6) && (value == 0) ) {
 			/* Blank out leading zeros. */
 			const ui_rect_t rect = { point, glyph.size };
-			portapack_lcd_fill_rectangle(rect, color_background);
+			portapack_fill_rectangle(rect, color_background);
 		} else {
 			portapack_draw_bitmap(point, glyph, color_foreground, color_background);
 		}
@@ -1019,7 +486,7 @@ static void portapack_ui_set_antenna_bias(bool antenna_bias) {
 	(void)antenna_bias;
 }
 
-static const hackrf_ui_t portapack_ui = {
+const hackrf_ui_t portapack_hackrf_ui = {
 	&portapack_ui_init,
 	&portapack_ui_set_frequency,
 	&portapack_ui_set_sample_rate,
@@ -1034,9 +501,9 @@ static const hackrf_ui_t portapack_ui = {
 	&portapack_ui_set_antenna_bias,
 };
 
-const hackrf_ui_t* portapack_detect(void) {
-	if( jtag_pp_idcode() == 0x020A50DD ) {
-		return &portapack_ui;
+const hackrf_ui_t* portapack_hackrf_ui_init() {
+	if( portapack() ) {
+		return &portapack_hackrf_ui;
 	} else {
 		return NULL;
 	}
diff --git a/firmware/common/ui_portapack.h b/firmware/common/ui_portapack.h
index 0d2fc58e..22d27d9c 100644
--- a/firmware/common/ui_portapack.h
+++ b/firmware/common/ui_portapack.h
@@ -22,40 +22,8 @@
 #ifndef __UI_PORTAPACK_H__
 #define __UI_PORTAPACK_H__
 
-#include <stddef.h>
+#include "hackrf-ui.h"
 
-typedef struct ui_color_t {
-	uint16_t v;
-} ui_color_t;
-
-typedef struct ui_point_t {
-	int16_t x;
-	int16_t y;
-} ui_point_t;
-
-typedef struct ui_size_t {
-	int16_t width;
-	int16_t height;
-} ui_size_t;
-
-typedef struct ui_rect_t {
-	ui_point_t point;
-	ui_size_t size;
-} ui_rect_t;
-
-typedef struct ui_bitmap_t {
-	ui_size_t size;
-	const uint8_t* const data;
-} ui_bitmap_t;
-
-typedef struct ui_font_t {
-	const ui_size_t glyph_size;
-	const uint8_t* const data;
-	char c_start;
-	size_t c_count;
-	size_t data_stride;
-} ui_font_t;
-
-const hackrf_ui_t* portapack_detect(void);
+const hackrf_ui_t* portapack_hackrf_ui_init() __attribute__((weak));
 
 #endif/*__UI_PORTAPACK_H__*/
diff --git a/firmware/common/ui_rad1o.c b/firmware/common/ui_rad1o.c
index 4d3b1254..aac72369 100644
--- a/firmware/common/ui_rad1o.c
+++ b/firmware/common/ui_rad1o.c
@@ -19,7 +19,6 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#include "hackrf-ui.h"
 #include "ui_rad1o.h"
 
 /* Weak functions from rad1o app */
diff --git a/firmware/common/ui_rad1o.h b/firmware/common/ui_rad1o.h
index 6e658e5b..7c14a79a 100644
--- a/firmware/common/ui_rad1o.h
+++ b/firmware/common/ui_rad1o.h
@@ -22,6 +22,8 @@
 #ifndef __UI_RAD1O_H__
 #define __UI_RAD1O_H__
 
-const hackrf_ui_t* rad1o_ui_setup(void);
+#include "hackrf-ui.h"
+
+const hackrf_ui_t* rad1o_ui_setup(void) __attribute__((weak));
 
 #endif/*__UI_RAD1O_H__*/
diff --git a/firmware/hackrf_usb/CMakeLists.txt b/firmware/hackrf_usb/CMakeLists.txt
index 271bf434..7e124b1f 100644
--- a/firmware/hackrf_usb/CMakeLists.txt
+++ b/firmware/hackrf_usb/CMakeLists.txt
@@ -66,6 +66,7 @@ set(SRC_M4
 if(BOARD STREQUAL "HACKRF_ONE")
 	SET(SRC_M4
 		${SRC_M4}
+		"${PATH_HACKRF_FIRMWARE_COMMON}/portapack.c"
 		"${PATH_HACKRF_FIRMWARE_COMMON}/ui_portapack.c"
 	)
 endif()
diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index 4714dbfe..92ab9aa2 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -46,6 +46,7 @@
 #include "usb_api_transceiver.h"
 #include "usb_bulk_buffer.h"
 #include "cpld_xc2c.h"
+#include "portapack.h"
  
 #include "hackrf-ui.h"
 
@@ -235,6 +236,10 @@ int main(void) {
 		halt_and_flash(6000000);
 	}
 
+#ifdef HACKRF_ONE
+	portapack_init();
+#endif
+
 #ifndef DFU_MODE
 	usb_set_descriptor_by_serial_number();
 #endif
diff --git a/firmware/hackrf_usb/usb_api_transceiver.c b/firmware/hackrf_usb/usb_api_transceiver.c
index fda9b6a9..3d64d7f9 100644
--- a/firmware/hackrf_usb/usb_api_transceiver.c
+++ b/firmware/hackrf_usb/usb_api_transceiver.c
@@ -273,7 +273,7 @@ void set_transceiver_mode(const transceiver_mode_t new_transceiver_mode) {
 
 
 	if( _transceiver_mode != TRANSCEIVER_MODE_OFF ) {
-		si5351c_activate_best_clock_source(&clock_gen);
+		activate_best_clock_source();
 
         hw_sync_enable(_hw_sync_mode);