Bring back and fix up util.c functionality.

Rip out the existing nonportable pieces, and shove them under
wirish/stm32f1, using weak symbols so users who only want libmaple
proper don't end up with build errors. Add stubbed-out (and only
partially functional) definitions for F2 targets under wirish/stm32f2.

The behavior on F103 targets is the same as it was before (though the
assertion framework has always been broken and badly needs
replacement, that awaits another commit). We additionally now skip
re-enabling USB on F1 targets without USB, to make things work on
value line MCUs.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

1 files changed, 42 insertions, 77 deletions

diff --git a/libmaple/util.c b/libmaple/util.c
index 88da075..2ee5ede 100644
--- a/libmaple/util.c
+++ b/libmaple/util.c
@@ -26,27 +26,17 @@
 
 /**
  * @file libmaple/util.c
- * @brief Utility procedures for debugging, mostly an error LED fade
- *        and messages dumped over a UART for failed asserts.
+ * @brief Utility procedures for debugging
  */
 
 #include <libmaple/libmaple.h>
 #include <libmaple/usart.h>
 #include <libmaple/gpio.h>
 #include <libmaple/nvic.h>
-#include <libmaple/adc.h>
-#include <libmaple/timer.h>
 
-/* FIXME [0.0.13] put this stuff back in some form. Move to Wirish? */
-
-/* Failed ASSERT()s send out a message using this USART config. */
-#ifndef ERROR_USART
-#define ERROR_USART            USART2
-#define ERROR_USART_CLK_SPEED  STM32_PCLK1
-#define ERROR_USART_BAUD       9600
-#define ERROR_TX_PORT          GPIOA
-#define ERROR_TX_PIN           2
-#endif
+/* (Undocumented) hooks used by Wirish to direct our behavior here */
+extern __weak void __lm_error(void);
+extern __weak usart_dev* __lm_enable_error_usart(void);
 
 /* If you define ERROR_LED_PORT and ERROR_LED_PIN, then a failed
  * ASSERT() will also throb() an LED connected to that port and pin.
@@ -55,100 +45,75 @@
 #define HAVE_ERROR_LED
 #endif
 
-/**
- * @brief Disables all peripheral interrupts except USB and fades the
- *        error LED.
- */
 /* (Called from exc.S with global interrupts disabled.) */
-void __error(void) {
-    /* Turn off peripheral interrupts */
-    nvic_irq_disable_all();
-
-    /* /\* Turn off timers *\/ */
-    /* timer_disable_all(); */
-
-    /* /\* Turn off ADC *\/ */
-    /* adc_disable_all(); */
-
-    /* /\* Turn off all USARTs *\/ */
-    /* usart_disable_all(); */
-
-    /* /\* Turn the USB interrupt back on so the bootloader keeps on functioning *\/ */
-    /* nvic_irq_enable(NVIC_USB_HP_CAN_TX); */
-    /* nvic_irq_enable(NVIC_USB_LP_CAN_RX0); */
-
+__attribute__((noreturn)) void __error(void) {
+    if (__lm_error) {
+        __lm_error();
+    }
     /* Reenable global interrupts */
     nvic_globalirq_enable();
     throb();
 }
 
-/**
- * @brief Enable the error USART for writing.
- * @sideeffect Configures ERROR_USART appropriately for writing.
- */
-void _enable_error_usart() {
-    /* gpio_set_mode(ERROR_TX_PORT, ERROR_TX_PIN, GPIO_AF_OUTPUT_PP); */
-    /* usart_init(ERROR_USART); */
-    /* usart_set_baud_rate(ERROR_USART, ERROR_USART_CLK_SPEED, ERROR_USART_BAUD); */
-}
-
-/**
- * @brief Print an error message on a UART upon a failed assertion
- *        and throb the error LED, if there is one defined.
+/*
+ * Print an error message on a UART upon a failed assertion (if one is
+ * available), and punt to __error().
+ *
  * @param file Source file of failed assertion
  * @param line Source line of failed assertion
  * @param exp String representation of failed assertion
  * @sideeffect Turns of all peripheral interrupts except USB.
  */
 void _fail(const char* file, int line, const char* exp) {
-    /* Initialize the error USART */
-    /* _enable_error_usart(); */
-
-    /* /\* Print failed assert message *\/ */
-    /* usart_putstr(ERROR_USART, "ERROR: FAILED ASSERT("); */
-    /* usart_putstr(ERROR_USART, exp); */
-    /* usart_putstr(ERROR_USART, "): "); */
-    /* usart_putstr(ERROR_USART, file); */
-    /* usart_putstr(ERROR_USART, ": "); */
-    /* usart_putudec(ERROR_USART, line); */
-    /* usart_putc(ERROR_USART, '\n'); */
-    /* usart_putc(ERROR_USART, '\r'); */
-
+    if (__lm_enable_error_usart) {
+        /* Initialize the error USART */
+        usart_dev *err_usart = __lm_enable_error_usart();
+
+        /* Print failed assert message */
+        usart_putstr(err_usart, "ERROR: FAILED ASSERT(");
+        usart_putstr(err_usart, exp);
+        usart_putstr(err_usart, "): ");
+        usart_putstr(err_usart, file);
+        usart_putstr(err_usart, ": ");
+        usart_putudec(err_usart, line);
+        usart_putc(err_usart, '\n');
+        usart_putc(err_usart, '\r');
+    }
     /* Shutdown and error fade */
     __error();
 }
 
-/**
- * @brief Provide an __assert_func handler to libc so that calls to assert() get
- *        redirected to _fail.
+/*
+ * Provide an __assert_func handler to libc so that calls to assert()
+ * get redirected to _fail.
  */
 void __assert_func(const char* file, int line, const char* method,
                    const char* expression) {
     _fail(file, line, expression);
 }
 
-/**
- * @brief Provide an abort() implementation that aborts execution and enters an
- *        error state with the throbbing LED indicator.
+/*
+ * Provide an abort() implementation that aborts execution and punts
+ * to __error().
  */
 void abort() {
-    /* /\* Initialize the error USART *\/ */
-    /* _enable_error_usart(); */
-
-    /* /\* Print abort message. *\/ */
-    /* usart_putstr(ERROR_USART, "ERROR: PROGRAM ABORTED VIA abort()\n\r"); */
+    if (__lm_enable_error_usart) {
+        /* Initialize the error USART */
+        usart_dev *err_usart = __lm_enable_error_usart();
+        /* Print abort message. */
+        usart_putstr(err_usart, "ERROR: PROGRAM ABORTED VIA abort()\r\n");
+    }
 
-    /* /\* Shutdown and error fade *\/ */
-    /* __error(); */
-    while (1)
-        ;
+    /* Shutdown and error fade */
+    __error();
 }
 
+/* This was public as of v0.0.12, so we've got to keep it public. */
 /**
  * @brief Fades the error LED on and off
  * @sideeffect Sets output push-pull on ERROR_LED_PIN.
  */
-void throb(void) {
+__attribute__((noreturn)) void throb(void) {
 #ifdef HAVE_ERROR_LED
     int32  slope   = 1;
     uint32 CC      = 0x0000;