From ca7eaec90352eae4b1b2317c9f30c6416d35dfac Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Thu, 8 Mar 2018 11:31:00 -0800
Subject: [PATCH] blue-pill: cleaning some stuff up

---
 blue-pill/draugr/Makefile  | 30 ++++++++++++++++++++++++------
 blue-pill/draugr/blink.cc  |  2 +-
 blue-pill/draugr/startup.s |  9 ++++-----
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/blue-pill/draugr/Makefile b/blue-pill/draugr/Makefile
index 34fefa9..210204d 100644
--- a/blue-pill/draugr/Makefile
+++ b/blue-pill/draugr/Makefile
@@ -15,6 +15,8 @@ CXX :=		$(ARMTC)-g++
 LD :=		$(ARMTC)-ld
 ARMSIZE :=	$(ARMTC)-size
 OBJCOPY :=	$(ARMTC)-objcopy
+PAGER ?=	less
+OPENOCD ?=	/usr/share/openocd
 
 # compiler options
 CPUFLAGS :=	-mcpu=cortex-m3 -mthumb
@@ -26,8 +28,7 @@ LDLIBS :=	-lc -lnosys
 # programmer options
 STARTMEM :=	0x8000000
 
-# targets
-
+### build targets ###
 .PHONY: all
 all: $(BIN)
 
@@ -38,6 +39,11 @@ $(ELF): $(OBJS)
 $(BIN): $(ELF)
 	$(OBJCOPY) -O binary $< $@
 
+.PHONY: clean
+clean:
+	rm -f *.o *.bin *.elf *.d *.map
+
+### programming targets ###
 .PHONY: flash
 flash: $(BIN)
 	st-flash write $(BIN) $(STARTMEM)
@@ -46,10 +52,22 @@ flash: $(BIN)
 erase:
 	st-flash erase
 
+.PHONY: reset
+reset:
+	st-flash reset
+
 .PHONY: install
-install: erase flash
+install: erase flash reset
 
-.PHONY: clean
-clean:
-	rm -f *.o *.bin *.elf *.d *.map
+### miscellaneous targets ###
+.PHONY: disass
+disass: $(ELF)
+	$(ARMTC)-objdump -D $(ELF) | $(PAGER)
 
+.PHONY: dump
+dump: $(ELF)
+	$(ARMTC)-objdump -D $(ELF) > $(TARGET).dump
+
+.PHONY: ocd
+ocd:
+	openocd -f $(OPENOCD)/scripts/interface/stlink-v2.cfg -f $(OPENOCD)/scripts/target/stm32f1x.cfg
diff --git a/blue-pill/draugr/blink.cc b/blue-pill/draugr/blink.cc
index 7de7ceb..81b9729 100644
--- a/blue-pill/draugr/blink.cc
+++ b/blue-pill/draugr/blink.cc
@@ -10,7 +10,7 @@ main() {
     GPIO_C->enable_clock();
     GPIO_C->pin_mode(LED, true, OUTPUT_GPP, OUTPUT_MAX_2MHZ);
 
-    while(1) {
+    while (true) {
 	    GPIO_C->pin_clear(LED);
 	    delay(LDELAY);
 	    GPIO_C->pin_set(LED);
diff --git a/blue-pill/draugr/startup.s b/blue-pill/draugr/startup.s
index f55d87c..5c55a35 100644
--- a/blue-pill/draugr/startup.s
+++ b/blue-pill/draugr/startup.s
@@ -1,17 +1,17 @@
 /*
  * Startup code for the STM32F103-based blue pill board.
  *
- * TODO: revisit stack pointer
- * TODO: is the IRQv buffer actually needed right now?
+ * The stack pointer is initialised to the top of the stack (which
+ * grows downward), so I pointed it to the end of the SRAM (where the
+ * stack should be).
  */
 
 .cpu cortex-m3
 .thumb
 
-.globl	vectors
 vectors:
 .align	2
-.long	0x20002000		/* best guess at stack pointer */
+.long	0x20005000		/* stack pointer points to top of SRAM */
 .long	reset_handler		/* reset handler */
 .long	hang			/* NMI handler */
 .long	hang			/* hard_fault_handler */
@@ -30,7 +30,6 @@ vectors:
 .thumb_func
 hang:   b .
 
-
 .thumb_func
 reset_handler:
 	bl	main