Create new non-timer based blink app

Now that timeslicing is up and running, there is no harm in having a
synchronous blink app and it is useful for porting new hardware (before
a driver for the hardware driver has been implemented).

Renames the timer-based, asynchronous, blink app to "blink" and creates
a new synchronous app (that just spins for a while) called "blink_sync".

apps/c_blinky/Makefile → apps/blink/Makefile

@@ -1,5 +1,5 @@
 TOCK_APPS_DIR=..
-APP=c_blinky
+APP=blink
 
 include $(TOCK_APPS_DIR)/Makefile.GenericApp.mk
 

apps/blink_sync/Makefile

@@ -0,0 +1,6 @@
+TOCK_APPS_DIR=..
+APP=blink_sync
+
+include $(TOCK_APPS_DIR)/Makefile.GenericApp.mk
+
+CPPFLAGS += -DSTACK_SIZE=2048

apps/blink_sync/loader.ld

@@ -0,0 +1,56 @@
+ENTRY(_start)
+
+MEMORY {
+    FLASH (rx) : ORIGIN = 0x80000000, LENGTH = 0x00080000
+    SRAM (RWX) : ORIGIN = 0x00000000, LENGTH = 0x00002000
+}
+
+SECTIONS {
+/* Load information, used by runtime to load app */
+    .load_info :
+    {
+        KEEP(*(.load_info))
+    } > FLASH =0xFF
+
+/* Text section, Code! */
+    .text :
+    {
+        _text = .;
+        KEEP (*(.start))
+        *(.text*)
+        *(.rodata*)
+        KEEP (*(.syscalls))
+        _etext = .;
+    } > FLASH =0xFF
+
+/* Global Offset Table */
+    .got :
+    {
+        _got = .;
+        *(.got*)
+        _egot = .;
+        _plt = .;
+        *(.got.plt*)
+        _eplt = .;
+    } > SRAM AT > FLASH
+
+/* Data section, static initialized variables
+ *  Note: This is placed in Flash after the text section, but needs to be
+ *  moved to SRAM at runtime
+ */
+    .data :
+    {
+        _data = .;
+        *(.data*)
+        _edata = .;
+    } > SRAM AT > FLASH
+
+/* BSS section, static uninitialized variables */
+    .bss :
+    {
+        _bss = .;
+        *(.bss*)
+        *(COMMON)
+        _ebss = .;
+    } > SRAM
+}

apps/blink_sync/main.c

@@ -0,0 +1,50 @@
+#include <firestorm.h>
+#include <gpio.h>
+
+/* Delay for for the given microseconds (approximately).
+ *
+ * For a 16 MHz CPU, 1us == 16 instructions (assuming each instruction takes
+ * one cycle). */
+static void busy_delay_us(int duration)
+{
+	// The inner loop instructions are: 14 NOPs + 1 SUBS/ADDS + 1 CMP
+	while (duration-- != 0) {
+		__asm volatile (
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+			"nop\n"
+		);
+	}
+}
+
+/* Delay for for the given milliseconds (approximately).
+ *
+ * Note that this is not precise as there are 2 extra instructions on the inner
+ * loop. Therefore, there is 1us added every 8 iterations. */
+static void busy_delay_ms(int duration)
+{
+	while (duration-- != 0) {
+		busy_delay_us(1000);
+	}
+}
+
+void main(void) {
+    gpio_enable_output(LED_0);
+
+    while(1) {
+      gpio_toggle(LED_0);
+      busy_delay_ms(500);
+    }
+}
+