Cleaned out libmaple.h; this had wide-ranging implications.

Many of the #defines in libmaple.h were board-specific, not
MCU-specific.  Most of these were only used by code under
libmaple/usb/.  These were moved into usb_config.h, and are clearly
marked as being terrible hacks.  I'm going to treat the USB stack as a
black box that we'll deal with later.

Further, instead of having a variety of #defines like "How many USARTS
do I have?", we decide that based on the density of the chip.  This is
determined by testing for STM32_MEDIUM_DENSITY or STM32_HIGH_DENSITY
defines.  libmaple currently doesn't support low-density chips, so
that suffices.  The Makefile will set these automatically based on the
MCU.

Other offending #defines are ERROR_LED_PORT and ERROR_LED_PIN; these
were made optional, but they're set in the Makefile as a hack to keep
things working.

14 files changed, 210 insertions, 216 deletions

diff --git a/libmaple/adc.c b/libmaple/adc.c
index 17d63b8..cd71118 100644
--- a/libmaple/adc.c
+++ b/libmaple/adc.c
@@ -49,7 +49,7 @@ adc_dev adc2 = {
 };
 const adc_dev *ADC2 = &adc2;
 
-#if NR_ADCS >= 3
+#ifdef STM32_HIGH_DENSITY
 adc_dev adc3 = {
     .regs   = ADC3_BASE,
     .clk_id = RCC_ADC3
diff --git a/libmaple/adc.h b/libmaple/adc.h
index ab6e643..ac386fb 100644
--- a/libmaple/adc.h
+++ b/libmaple/adc.h
@@ -68,7 +68,7 @@ typedef struct adc_dev {
 
 extern const adc_dev *ADC1;
 extern const adc_dev *ADC2;
-#if NR_ADCS >= 3
+#ifdef STM32_HIGH_DENSITY
 extern const adc_dev *ADC3;
 #endif
 
@@ -190,7 +190,7 @@ static inline void adc_disable(const adc_dev *dev) {
 static inline void adc_disable_all(void) {
     adc_disable(ADC1);
     adc_disable(ADC2);
-#if NR_ADCS >= 3
+#ifdef STM32_HIGH_DENSITY
     adc_disable(ADC3);
 #endif
 }
diff --git a/libmaple/bkp.c b/libmaple/bkp.c
index ac9aeae..ed107d8 100644
--- a/libmaple/bkp.c
+++ b/libmaple/bkp.c
@@ -69,7 +69,8 @@ void bkp_disable_writes(void) {
 
 /**
  * Read a value from given backup data register.
- * @param reg Data register to read, from 1 to NR_BKP_REGS (10 on Maple).
+ * @param reg Data register to read, from 1 to BKP_NR_DATA_REGS (10 on
+ *            medium-density devices, 42 on high-density devices).
  */
 uint16 bkp_read(uint8 reg) {
     __io uint32* dr = data_register(reg);
@@ -85,7 +86,8 @@ uint16 bkp_read(uint8 reg) {
  *
  * Write access to backup registers must be enabled.
  *
- * @param reg Data register to write, from 1 to NR_BKP_REGS (10 on Maple).
+ * @param reg Data register to write, from 1 to BKP_NR_DATA_REGS (10
+ *            on medium-density devices, 42 on high-density devices).
  * @param val Value to write into the register.
  * @see bkp_enable_writes()
  */
@@ -101,16 +103,16 @@ void bkp_write(uint8 reg, uint16 val) {
 /*
  * Data register memory layout is not contiguous. It's split up from
  * 1--NR_LOW_DRS, beginning at BKP_BASE->DR1, through to
- * (NR_LOW_DRS+1)--NR_BKP_REGS, beginning at BKP_BASE->DR10.
+ * (NR_LOW_DRS+1)--BKP_NR_DATA_REGS, beginning at BKP_BASE->DR11.
  */
 #define NR_LOW_DRS 10
 
 static inline __io uint32* data_register(uint8 reg) {
-    if (reg < 1 || reg > NR_BKP_REGS) {
+    if (reg < 1 || reg > BKP_NR_DATA_REGS) {
         return 0;
     }
 
-#if NR_BKP_REGS == NR_LOW_DRS
+#if BKP_NR_DATA_REGS == NR_LOW_DRS
     return (uint32*)BKP_BASE + reg;
 #else
     if (reg <= NR_LOW_DRS) {
diff --git a/libmaple/bkp.h b/libmaple/bkp.h
index ce8e6c7..96ef8d2 100644
--- a/libmaple/bkp.h
+++ b/libmaple/bkp.h
@@ -38,6 +38,12 @@
 extern "C" {
 #endif
 
+#if defined(STM32_MEDIUM_DENSITY)
+#define BKP_NR_DATA_REGS 10
+#elif defined(STM32_HIGH_DENSITY)
+#define BKP_NR_DATA_REGS 42
+#endif
+
 typedef struct bkp_reg_map {
     const uint32 RESERVED1;
     __io uint32 DR1;            ///< Data register 1
@@ -53,7 +59,7 @@ typedef struct bkp_reg_map {
     __io uint32 RTCCR;          ///< RTC control register
     __io uint32 CR;             ///< Control register
     __io uint32 CSR;            ///< Control and status register
-#if NR_BKP_REGS > 10
+#ifdef STM32_HIGH_DENSITY
     const uint32 RESERVED2;
     const uint32 RESERVED3;
     __io uint32 DR11;           ///< Data register 11
diff --git a/libmaple/libmaple.h b/libmaple/libmaple.h
index 4f9a71a..6b75c96 100644
--- a/libmaple/libmaple.h
+++ b/libmaple/libmaple.h
@@ -24,164 +24,50 @@
 
 /**
  *  @file libmaple.h
- *
- *  @brief general include file for libmaple
+ *  @brief General include file for libmaple
  */
 
 #ifndef _LIBMAPLE_H_
 #define _LIBMAPLE_H_
 
 #include "libmaple_types.h"
+#include "util.h"
 
-/* General configuration */
-#define DEBUG_NONE      0
-#define DEBUG_FAULT     1
-#define DEBUG_ALL       2
-
-#ifndef DEBUG_LEVEL
-#define DEBUG_LEVEL DEBUG_ALL
-#endif
+/*
+ * Where to put usercode, based on space reserved for bootloader.
+ *
+ * FIXME this has no business being here 
+ */
+#define USER_ADDR_ROM 0x08005000
+#define USER_ADDR_RAM 0x20000C00
+#define STACK_TOP     0x20000800
 
 /* MCU-specific configuration */
 #if defined(MCU_STM32F103RB)
     /* e.g., LeafLabs Maple */
 
     /* Number of GPIO ports (GPIOA, GPIOB, etc.) */
-    #define NR_GPIO_PORTS             4
-
-    /* Total number of GPIO pins */
-    #define NR_GPIO_PINS             39
-
-    /* Number of 16-bit backup registers */
-    #define NR_BKP_REGS              10
-
-    /* Number of timer devices ports, definitely used */
-    #define NR_TIMERS                 4
-
-    /* Number of USART ports */
-    #define NR_USART                  3
-
-    /* Number of ADCs */
-    #define NR_ADCS                   2
-
-    /* Has an FSMC bus? */
-    #define NR_FSMC                   0
-
-    /* Has a DAC? */
-    #define NR_DAC_PINS               0
-
-    /* USB Identifier numbers */
-    /* Descriptor strings must be modified by hand in
-       usb/descriptors.c for now */
-    #define VCOM_ID_VENDOR    0x1EAF
-    #define VCOM_ID_PRODUCT   0x0004
-    #define USB_DISC_BANK     GPIOC_BASE
-    #define USB_DISC_PIN      12
-    #define USB_CONFIG_MAX_POWER      (100 >> 1)
-    #define RESET_DELAY               (100)
-
-    /* Where to put usercode (based on space reserved for bootloader) */
-    #define USER_ADDR_ROM 0x08005000
-    #define USER_ADDR_RAM 0x20000C00
-    #define STACK_TOP     0x20000800
-
-    /* Debug port settings (from ASSERT) */
-    #define ERROR_LED_PORT         GPIOB_BASE
-    #define ERROR_LED_PIN          12
-    #define ERROR_USART_NUM        USART2
-    #define ERROR_USART_BAUD       9600
-    #define ERROR_TX_PORT          GPIOA_BASE
-    #define ERROR_TX_PIN           2
-
-    /* Just in case, most boards have at least some memory */
-    #ifndef RAMSIZE
-    #  define RAMSIZE             (caddr_t)0x50000
-    #endif
-
-    /* Bitbanded Memory sections */
-    #define BITBAND_SRAM_REF   0x20000000
-    #define BITBAND_SRAM_BASE  0x22000000
-    #define BITBAND_PERI_REF   0x40000000
-    #define BITBAND_PERI_BASE  0x42000000
+    #define NR_GPIO_PORTS              4
+
+    /* SRAM size, in bytes */
+    #define SRAM_SIZE             0x5000
 
 #elif defined(MCU_STM32F103ZE)
     /* e.g., LeafLabs Maple Native */
 
-    #define NR_GPIO_PORTS             7
-    #define NR_GPIO_PINS            100
-    #define NR_BKP_REGS              42 /* TODO test on Native */
-    #define NR_TIMERS                 8
-    #define NR_USART                  5 /* NB: 4 and 5 are UART only */
-    #define NR_ADCS                   3
-    #define NR_FSMC                   1
-    #define NR_DAC_PINS               2
-
-    #define VCOM_ID_VENDOR    0x1EAF
-    #define VCOM_ID_PRODUCT   0x0004
-    #define USB_DISC_BANK     GPIOB_BASE
-    #define USB_DISC_PIN      8
-    #define USB_CONFIG_MAX_POWER      (100 >> 1)
-    #define RESET_DELAY               (100)
-
-    #define USER_ADDR_ROM 0x08005000
-    #define USER_ADDR_RAM 0x20000C00
-    #define STACK_TOP     0x20000800
-
-    #define ERROR_LED_PORT         GPIOC_BASE
-    #define ERROR_LED_PIN          15
-    #define ERROR_USART_NUM        USART1
-    #define ERROR_USART_BAUD       9600
-    #define ERROR_TX_PORT          GPIOA_BASE
-    #define ERROR_TX_PIN           10
-
-    #ifndef RAMSIZE
-    #  define RAMSIZE             (caddr_t)0x50000
-    #endif
-
-    #define BITBAND_SRAM_REF   0x20000000
-    #define BITBAND_SRAM_BASE  0x22000000
-    #define BITBAND_PERI_REF   0x40000000
-    #define BITBAND_PERI_BASE  0x42000000
+    #define NR_GPIO_PORTS              7
+
+    #define SRAM_SIZE            0x10000
 
 #elif defined(MCU_STM32F103CB)
     /* e.g., LeafLabs Maple Mini */
 
-    #define NR_GPIO_PORTS 3
-    #define NR_GPIO_PINS  34
-    #define NR_BKP_REGS   10    /* TODO test on Mini */
-    #define NR_TIMERS     4
-    #define NR_USART      3
-    #define NR_ADCS       2
-    #define NR_FSMC       0
-    #define NR_DAC_PINS   0
-
-    #define VCOM_ID_VENDOR       0x1EAF
-    #define VCOM_ID_PRODUCT      0x0005
-    #define USB_DISC_BANK        GPIOB_BASE
-    #define USB_DISC_PIN         9
-    #define USB_CONFIG_MAX_POWER (100 >> 1)
-    #define RESET_DELAY          100
-
-    #define USER_ADDR_ROM 0x08005000
-    #define USER_ADDR_RAM 0x20000C00
-    #define STACK_TOP     0x20000800
-
-    #define ERROR_LED_PORT   GPIOB_BASE
-    #define ERROR_LED_PIN    12
-    #define ERROR_USART_NUM  USART2
-    #define ERROR_USART_BAUD 9600
-    #define ERROR_TX_PORT    GPIOA_BASE
-    #define ERROR_TX_PIN     2
-
-    #ifndef RAMSIZE
-    #  define RAMSIZE             (caddr_t)0x50000
-    #endif
-
-    /* Bitbanded Memory sections */
-    #define BITBAND_SRAM_REF   0x20000000
-    #define BITBAND_SRAM_BASE  0x22000000
-    #define BITBAND_PERI_REF   0x40000000
-    #define BITBAND_PERI_BASE  0x42000000
+    /* Note that this is not, strictly speaking, true.  But only pins
+       0 and 1 exist, and they're used for OSC on the Mini, so we'll
+       live with this for now. */
+    #define NR_GPIO_PORTS              3
+
+    #define SRAM_SIZE             0x5000
 
 #else
 
@@ -190,8 +76,5 @@
 
 #endif
 
-/* Requires board configuration info */
-#include "util.h"
-
 #endif
 
diff --git a/libmaple/libmaple_types.h b/libmaple/libmaple_types.h
index 8d216a8..a976a9e 100644
--- a/libmaple/libmaple_types.h
+++ b/libmaple/libmaple_types.h
@@ -45,8 +45,6 @@ typedef void (*voidFuncPtr)(void);
 
 #define __io volatile
 
-#define ALWAYS_INLINE inline __attribute__((always_inline))
-
 #ifndef NULL
 #define NULL 0
 #endif
diff --git a/libmaple/timers.c b/libmaple/timers.c
index 29aeeba..ff548c0 100644
--- a/libmaple/timers.c
+++ b/libmaple/timers.c
@@ -55,7 +55,7 @@ struct timer_dev timer_dev_table[] = {
         .rcc_dev_num = RCC_TIMER4,
         .nvic_dev_num = NVIC_TIMER4
     },
-#if NR_TIMERS >= 8
+#ifdef STM32_HIGH_DENSITY
     /* High density devices only (eg, Maple Native) */
     [TIMER5] = {
         .base = (timer_port*)TIMER5_BASE,
@@ -82,7 +82,7 @@ void timer_init(timer_dev_num timer_num, uint16 prescale) {
     if (timer_num == TIMER1) {
         is_advanced = 1;
     }
-#if NR_TIMERS >= 8
+#ifdef STM32_HIGH_DENSITY
     if (timer_num == TIMER8) {
         is_advanced = 1;
     }
@@ -193,12 +193,8 @@ void timer_set_reload(timer_dev_num timer_num, uint16 max_reload) {
  * or similar to prevent interrupts and PWM output without 16 seperate function
  * calls to timer_set_mode */
 void timer_disable_all(void) {
-    // TODO: refactor
-
-    /* Note: this must be very robust because it gets called from,
-       e.g., ASSERT */
     timer_port *timer;
-#if NR_TIMERS >= 8
+#ifdef STM32_HIGH_DENSITY
     timer_port *timers[6] = { (timer_port*)TIMER1_BASE,
                               (timer_port*)TIMER2_BASE,
                               (timer_port*)TIMER3_BASE,
diff --git a/libmaple/timers.h b/libmaple/timers.h
index 99bcab6..1f6afcd 100644
--- a/libmaple/timers.h
+++ b/libmaple/timers.h
@@ -206,7 +206,7 @@ typedef enum {
     TIMER2,      /*< General purpose timer TIM2 */
     TIMER3,      /*< General purpose timer TIM3 */
     TIMER4,      /*< General purpose timer TIM4 */
-#if NR_TIMERS >= 8
+#ifdef STM32_HIGH_DENSITY
     TIMER5,      /*< General purpose timer TIM5; high density only */
     /* FIXME maple native: put timers 6 and 7 back in and make the
        corresponding changes to timers.c */
@@ -412,8 +412,8 @@ void timer_generate_update(timer_dev_num timer_num);
 /**
  * Turn on PWM with duty_cycle.
  *
- * @param ccr TIMERx_CHn_CCR, where x goes from 1 to NR_TIMERS,
- * and n goes from 1 to 4.
+ * @param ccr TIMERx_CHn_CCR, where x ranges over timers, and n ranges
+ * from 1 to 4.
  *
  * @param duty_cycle: A number between 0 and
  * timer_get_compare_value(TIMERx, y), where x and y are as above.
diff --git a/libmaple/usart.c b/libmaple/usart.c
index 44a5c92..030d3cc 100644
--- a/libmaple/usart.c
+++ b/libmaple/usart.c
@@ -61,7 +61,7 @@ struct usart_dev usart_dev_table[] = {
         .rcc_dev_num = RCC_USART3,
         .nvic_dev_num = NVIC_USART3
     },
-#if NR_USART >= 5
+#ifdef STM32_HIGH_DENSITY
     /* TODO test */
     [UART4] = {
         .base = (usart_port*)UART4_BASE,
@@ -107,7 +107,7 @@ void USART3_IRQHandler(void) {
     usart_irq(USART3);
 }
 
-#if NR_USART >= 5
+#ifdef STM32_HIGH_DENSITY
 void UART4_IRQHandler(void) {
     usart_irq(UART4);
 }
@@ -124,7 +124,11 @@ void UART5_IRQHandler(void) {
  *  @param baud Baud rate to be set at
  */
 void usart_init(uint8 usart_num, uint32 baud) {
-    ASSERT(usart_num <= NR_USART);
+#ifdef STM32_HIGH_DENSITY
+    ASSERT(usart_num <= UART5);
+#else
+    ASSERT(usart_num <= USART3);
+#endif
     usart_port *port;
     ring_buffer *ring_buf;
 
@@ -170,7 +174,7 @@ void usart_disable_all() {
     usart_disable(USART1);
     usart_disable(USART2);
     usart_disable(USART3);
-#if NR_USART >= 5
+#ifdef STM32_HIGH_DENSITY
     usart_disable(UART4);
     usart_disable(UART5);
 #endif
diff --git a/libmaple/usart.h b/libmaple/usart.h
index 0ca3f55..90b3415 100644
--- a/libmaple/usart.h
+++ b/libmaple/usart.h
@@ -43,8 +43,10 @@ enum {
     USART1,
     USART2,
     USART3,
+#ifdef STM32_HIGH_DENSITY
     UART4,
     UART5,
+#endif
 };
 
 /* peripheral register struct  */
diff --git a/libmaple/usb/descriptors.c b/libmaple/usb/descriptors.c
index 360e6dd..8dd9521 100644
--- a/libmaple/usb/descriptors.c
+++ b/libmaple/usb/descriptors.c
@@ -150,43 +150,50 @@ const USB_Descriptor_Config usbVcomDescriptor_Config = {
  //  }
 };
 
-/*
-   String Identifiers:
+/*****************************************************************************
+ *****************************************************************************
+ ***
+ *** FIXME FIXME FIXME NOT THE RIGHT THING! MOVE ALL THIS INTO TO WIRISH!
+ ***
+ *****************************************************************************
+ *****************************************************************************/
 
-   we may choose to specify any or none of the following string
-   identifiers:
+const uint8 usbVcomDescriptor_LangID[USB_DESCRIPTOR_STRING_LEN(1)] = {
+    USB_DESCRIPTOR_STRING_LEN(1),
+    USB_DESCRIPTOR_TYPE_STRING,
+    0x09,
+    0x04
+};
 
-   iManufacturer:    LeafLabs
-   iProduct:         Maple R3
-   iSerialNumber:    NONE
-   iConfiguration:   NONE
-   iInterface(CCI):  NONE
-   iInterface(DCI):  NONE
+const uint8 usbVcomDescriptor_iManufacturer[USB_DESCRIPTOR_STRING_LEN(8)] = {
+    USB_DESCRIPTOR_STRING_LEN(8),
+    USB_DESCRIPTOR_TYPE_STRING,
+    'L', 0, 'e', 0, 'a', 0, 'f', 0,
+    'L', 0, 'a', 0, 'b', 0, 's', 0
+};
 
-   additionally we must provide the unicode language identifier,
-   which is 0x0409 for US English
-*/
+/*
+  String Identifiers:
 
-const uint8 usbVcomDescriptor_LangID[USB_DESCRIPTOR_STRING_LEN(1)] =
-{
-  USB_DESCRIPTOR_STRING_LEN(1),
-  USB_DESCRIPTOR_TYPE_STRING,
-  0x09,
-  0x04
-};
+  we may choose to specify any or none of the following string
+  identifiers:
 
-const uint8 usbVcomDescriptor_iManufacturer[USB_DESCRIPTOR_STRING_LEN(8)] =
-{
-  USB_DESCRIPTOR_STRING_LEN(8),
-  USB_DESCRIPTOR_TYPE_STRING,
-  'L', 0, 'e', 0, 'a', 0, 'f', 0,
-  'L', 0, 'a', 0, 'b', 0, 's', 0
-};
+  iManufacturer:    LeafLabs
+  iProduct:         Maple R3
+  iSerialNumber:    NONE
+  iConfiguration:   NONE
+  iInterface(CCI):  NONE
+  iInterface(DCI):  NONE
 
-const uint8 usbVcomDescriptor_iProduct[USB_DESCRIPTOR_STRING_LEN(8)] =
-{
-  USB_DESCRIPTOR_STRING_LEN(8),
-  USB_DESCRIPTOR_TYPE_STRING,
-  'M', 0, 'a', 0, 'p', 0, 'l', 0,
-  'e', 0, ' ', 0, 'R', 0, '3', 0
+  additionally we must provide the unicode language identifier,
+  which is 0x0409 for US English
+*/
+const uint8 usbVcomDescriptor_iProduct[USB_DESCRIPTOR_STRING_LEN(8)] = {
+    USB_DESCRIPTOR_STRING_LEN(8),
+    USB_DESCRIPTOR_TYPE_STRING,
+    'M', 0, 'a', 0, 'p', 0, 'l', 0,
+    'e', 0, ' ', 0, ' ', 0, ' ', 0
 };
+
+/*****************************************************************************
+ *****************************************************************************/
diff --git a/libmaple/usb/usb_config.h b/libmaple/usb/usb_config.h
index e5f3979..394c580 100644
--- a/libmaple/usb/usb_config.h
+++ b/libmaple/usb/usb_config.h
@@ -5,6 +5,67 @@
 
 #include "usb_lib.h"
 
+/******************************************************************************
+ ******************************************************************************
+ ***
+ ***   HACK ALERT
+ ***
+ ***   FIXME FIXME FIXME FIXME
+ ***
+ ***   A bunch of board-specific #defines that are only used by the
+ ***   USB routines got put into libmaple.h for what appear to be
+ ***   historical reasons.  I'm [mbolivar] putting them in here for
+ ***   now, so that we can treat the usb/ directory as a black box,
+ ***   freeing the rest of libmaple/ to be implemented as a
+ ***   general-purpose STM32 library. All of this REALLY needs to get
+ ***   moved into wirish when we get a chance to redo the USB stack.
+ ***
+ ******************************************************************************
+ *****************************************************************************/
+
+#define VCOM_ID_VENDOR            0x1EAF
+#define RESET_DELAY               (100)
+#define USB_CONFIG_MAX_POWER      (100 >> 1)
+
+#if defined(BOARD_maple)
+
+    /* USB Identifier numbers */
+    #define VCOM_ID_PRODUCT      0x0004
+    #define USB_DISC_BANK        GPIOC_BASE
+    #define USB_DISC_PIN         12
+
+#elif defined(BOARD_maple_mini)
+
+    #define VCOM_ID_PRODUCT      0x0005
+    #define USB_DISC_BANK        GPIOB_BASE
+    #define USB_DISC_PIN         9
+
+#elif defined(BOARD_maple_native)
+
+    #define VCOM_ID_PRODUCT      0x0006
+    #define USB_DISC_BANK        GPIOB_BASE
+    #define USB_DISC_PIN         8
+
+#else
+
+#error ("Sorry! the USB stack relies on LeafLabs board-specific "       \
+        "configuration right now.  If you want, you can pretend you're one " \
+        "of our boards; i.e., #define BOARD_maple, BOARD_maple_mini, or "  \
+        "BOARD_maple_native according to what matches your MCU best. " \
+        "You should also take a look at libmaple/usb/descriptors.c; we make " \
+        "some assumptions there that you probably won't like.")
+
+#endif
+
+/******************************************************************************
+ ******************************************************************************
+ ***
+ ***   END HACK
+ ***
+ ******************************************************************************
+ *****************************************************************************/
+
+
 /* choose addresses to give endpoints the max 64 byte buffers */
 #define USB_BTABLE_ADDRESS        0x00
 #define VCOM_CTRL_EPNUM           0x00
@@ -33,14 +94,15 @@
 #define NUM_ENDPTS                0x04
 
 /* handle all usb interrupts */
-#define ISR_MSK ( CNTR_CTRM    |           \
-		  CNTR_WKUPM   |	   \
-		  CNTR_SUSPM   |	   \
-		  CNTR_ERRM    |	   \
-		  CNTR_SOFM    |	   \
-		  CNTR_ESOFM   |	   \
-		  CNTR_RESETM  )
+#define ISR_MSK (CNTR_CTRM    |                                         \
+                 CNTR_WKUPM   |                                         \
+                 CNTR_SUSPM   |                                         \
+                 CNTR_ERRM    |                                         \
+                 CNTR_SOFM    |                                         \
+                 CNTR_ESOFM   |                                         \
+                 CNTR_RESETM)
 
 #define F_SUSPEND_ENABLED 1
 
+
 #endif
diff --git a/libmaple/util.c b/libmaple/util.c
index 11f9b34..481cd60 100644
--- a/libmaple/util.c
+++ b/libmaple/util.c
@@ -34,6 +34,21 @@
 #include "adc.h"
 #include "timers.h"
 
+/* Failed asserts send out a message on this USART. */
+#ifndef ERROR_USART_NUM
+#define ERROR_USART_NUM        USART2
+#define ERROR_USART_BAUD       9600
+#define ERROR_TX_PORT          GPIOA_BASE
+#define ERROR_TX_PIN           2
+#endif
+
+/* If you define ERROR_LED_PORT and ERROR_LED_PIN, then a failed
+   assert will also throb an LED connected to that port an pin.
+   FIXME this should work together with wirish somehow. */
+#if defined(ERROR_LED_PORT) && defined(ERROR_LED_PIN)
+#define HAVE_ERROR_LED
+#endif
+
 /* Error assert + fade */
 void _fail(const char* file, int line, const char* exp) {
     int32  slope   = 1;
@@ -67,8 +82,10 @@ void _fail(const char* file, int line, const char* exp) {
     usart_putc(ERROR_USART_NUM, '\n');
     usart_putc(ERROR_USART_NUM, '\r');
 
+#ifdef HAVE_ERROR_LED
     /* Turn on the error LED */
     gpio_set_mode(ERROR_LED_PORT, ERROR_LED_PIN, GPIO_MODE_OUTPUT_PP);
+#endif
 
     /* Turn the USB interrupt back on so the bootloader keeps on functioning */
     nvic_irq_enable(NVIC_INT_USBHP);
@@ -79,6 +96,7 @@ void _fail(const char* file, int line, const char* exp) {
 }
 
 void throb(void) {
+#ifdef HAVE_ERROR_LED
     int32  slope   = 1;
     uint32 CC      = 0x0000;
     uint32 TOP_CNT = 0x0200;
@@ -105,5 +123,10 @@ void throb(void) {
         }
         i++;
     }
+#else
+    /* No error LED is connected; do nothing. */
+    while (1)
+        ;
+#endif
 }
 
diff --git a/libmaple/util.h b/libmaple/util.h
index 63427cc..28ce970 100644
--- a/libmaple/util.h
+++ b/libmaple/util.h
@@ -32,7 +32,18 @@
 #ifndef _UTIL_H_
 #define _UTIL_H_
 
-#include "libmaple.h"
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+/* Debug configuration */
+#define DEBUG_NONE      0
+#define DEBUG_FAULT     1
+#define DEBUG_ALL       2
+
+#ifndef DEBUG_LEVEL
+#define DEBUG_LEVEL DEBUG_ALL
+#endif
 
 #define BIT(shift)                     (1UL << (shift))
 #define BIT_MASK_SHIFT(mask, shift)    ((mask) << (shift))
@@ -41,9 +52,14 @@
 #define GET_BITS(x, m, n) ((((uint32)x) << (31 - (n))) >> ((31 - (n)) + (m)))
 
 /* Bit-banding macros  */
+/* Bitbanded Memory sections */
+#define BITBAND_SRAM_REF   0x20000000
+#define BITBAND_SRAM_BASE  0x22000000
+#define BITBAND_PERI_REF   0x40000000
+#define BITBAND_PERI_BASE  0x42000000
 /* Convert SRAM address */
 #define BITBAND_SRAM(a,b) ((BITBAND_SRAM_BASE+(a-BITBAND_SRAM_REF)*32+(b*4)))
-/* Convert PERI address */
+/* Convert peripheral address */
 #define BITBAND_PERI(a, b) ((BITBAND_PERI_BASE +                \
                             ((uint32)a - BITBAND_PERI_REF) * 32 + (b * 4)))
 
@@ -63,18 +79,9 @@
 #define __write(reg, value)      (*(volatile uint32*)(reg) = (value))
 
 #define IS_POWER_OF_TWO(v)  (v && !(v & (v - 1)))
-
-#ifdef __cplusplus
-extern "C"{
-#endif
-
 void _fail(const char*, int, const char*);
 void throb(void);
 
-#ifdef __cplusplus
-} // extern "C"
-#endif
-
 /* Asserts for sanity checks, redefine DEBUG_LEVEL in libmaple.h to
  * compile out these checks */
 
@@ -100,5 +107,9 @@ void throb(void);
 #define ASSERT_FAULT(exp) (void)((0))
 #endif
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #endif