F2 F3 deprecate (#267)

* move f3-1 to f4, remove f3
* remove f2
* remove firmware F3 for pipeline
* remove patch for F4 makefile
* fix fw makefile
* migrate bootloader to f4

firmware/targets/f4/api-hal/api-hal-delay.c

@@ -0,0 +1,27 @@
+#include "api-hal-delay.h"
+#include "assert.h"
+#include "cmsis_os2.h"
+
+static uint32_t clk_per_microsecond;
+
+void delay_us_init_DWT(void) {
+    CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
+    DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
+    DWT->CYCCNT = 0U;
+    clk_per_microsecond = SystemCoreClock / 1000000.0f;
+}
+
+void delay_us(float microseconds) {
+    uint32_t start = DWT->CYCCNT;
+    uint32_t time_ticks = microseconds * clk_per_microsecond;
+    while((DWT->CYCCNT - start) < time_ticks) {
+    };
+}
+
+// cannot be used in ISR
+// TODO add delay_ISR variant
+void delay(float milliseconds) {
+    uint32_t ticks = milliseconds / (1000.0f / osKernelGetTickFreq());
+    osStatus_t result = osDelay(ticks);
+    assert(result == osOK);
+}