Rewrite STM32F4 stub in C and use new interface.

flashstub/Makefile

@@ -8,7 +8,7 @@ ifneq ($(V), 1)
 Q = @
 endif
 
-CFLAGS=-mcpu=cortex-m3 -mthumb -I../libopencm3/include
+CFLAGS=-Os -std=gnu99 -mcpu=cortex-m3 -mthumb -I../libopencm3/include
 ASFLAGS=-mcpu=cortex-m3 -mthumb
 
 all:	lmi.stub stm32f4.stub nrf51.stub stm32f1.stub
@@ -17,6 +17,10 @@ stm32f1.o: stm32f1.c
 	$(Q)echo "  CC      $<"
 	$(Q)$(CC) $(CFLAGS) -DSTM32F1 -o $@ -c $<
 
+stm32f4.o: stm32f4.c
+	$(Q)echo "  CC      $<"
+	$(Q)$(CC) $(CFLAGS) -DSTM32F4 -o $@ -c $<
+
 %.o:	%.s
 	$(Q)echo "  AS      $<"
 	$(Q)$(AS) $(ASFLAGS) -o $@ $<

flashstub/stm32f4.c

@@ -0,0 +1,40 @@
+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2015  Black Sphere Technologies Ltd.
+ * Written by Gareth McMullin <gareth@blacksphere.co.nz>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "libopencm3/stm32/flash.h"
+#include "stub.h"
+
+#define SR_ERROR_MASK 0xF2
+
+void __attribute__((naked))
+stm32f4_flash_write_stub(uint32_t *dest, uint32_t *src, uint32_t size)
+{
+	for (int i = 0; i < size; i += 4) {
+		FLASH_CR = FLASH_CR_PROGRAM_X32 | FLASH_CR_PG;
+		*dest++ = *src++;
+		while (FLASH_SR & FLASH_SR_BSY)
+			;
+	}
+
+	if (FLASH_SR & SR_ERROR_MASK)
+		stub_exit(1);
+
+	stub_exit(0);
+}
+

flashstub/stm32f4.s

@@ -1,44 +0,0 @@
-.global _start
-
-_start:
-	ldr r0, _flashbase
-	ldr r1, _addr
-	mov r2, pc
-	add r2, #(_data - . - 2)
-	ldr r3, _size
-	ldr r5, _cr
-_next:
-	cbz r3, _done
-	@ Write PG command to FLASH_CR
-	str r5, [r0, #0x10]
-	@ Write data to flash (word)
-	ldr r4, [r2]
-	str r4, [r1]
-
-_wait:	@ Wait for BSY bit to clear
-	ldrh r4, [r0, #0x0E]
-	mov r6, #1
-	tst r4, r6
-	bne _wait
-
-	sub r3, #4
-	add r1, #4
-	add r2, #4
-	b _next
-_done:
-	bkpt
-
-@.align 4
-.org 0x28
-_cr:
-	.word 0x00000201
-_flashbase:
-	.word 0x40023C00
-_addr:
-	.word 0x0800bf78
-_size:
-	.word 8
-_data:
-	.word 0xAAAAAAAA
-	.word 0xBBBBBBBB
-	.word 0xCCCCCCCC

flashstub/stm32f4.stub

@@ -0,0 +1 @@
+0x2300, 0x4293, 0x4C09, 0xD20B, 0x4D09, 0xF240, 0x2601, 0x602E, 0x58CD, 0x50C5, 0x6825, 0xF415, 0x3F80, 0xD1FB, 0x3304, 0xE7F0, 0x6823, 0xF013, 0x0FF2, 0xD000, 0xBE01, 0xBE00, 0x3C0C, 0x4002, 0x3C10, 0x4002, 

src/stm32f4.c

@@ -33,6 +33,7 @@
 #include "general.h"
 #include "adiv5.h"
 #include "target.h"
+#include "cortexm.h"
 #include "command.h"
 #include "gdb_packet.h"
 
@@ -120,44 +121,12 @@ static const char stm32f4_xml_memory_map[] = "<?xml version=\"1.0\"?>"
 
 /* This routine is uses word access.  Only usable on target voltage >2.7V */
 static const uint16_t stm32f4_flash_write_stub[] = {
-// _start:
+#include "../flashstub/stm32f4.stub"
-	0x480a,	// ldr r0, [pc, #40] // _flashbase
-	0x490b,	// ldr r1, [pc, #44] // _addr
-	0x467a, // mov r2, pc
-	0x3230, // adds r2, #48
-	0x4b0a, // ldr r3, [pc, #36] // _size
- 	0x4d07, // ldr r5, [pc, #28] // _cr
-// _next:
- 	0xb153, // cbz r3, _done
-	0x6105, // str r5, [r0, #16]
-	0x6814, // ldr r4, [r2]
-	0x600c, // str r4, [r1]
-// _wait:
-	0x89c4, // ldrb r4, [r0, #14]
-	0x2601, // movs r6, #1
-	0x4234, // tst r4, r6
-	0xd1fb, // bne _wait
-
-	0x3b04, // subs r3, #4
-	0x3104, // adds r1, #4
-	0x3204, // adds r2, #4
-	0xe7f3, // b _next
-// _done:
-	0xbe00, // bkpt
-	0x0000,
-// .org 0x28
-//_cr:
-	0x0201, 0x0000, //.word 0x00000201 (Value to write to FLASH_CR) */
-// _flashbase:
- 	0x3c00, 0x4002, // .word 0x40023c00 (FPEC_BASE)
-// _addr:
-// 	0x0000, 0x0000,
-// _size:
-// 	0x0000, 0x0000,
-// _data:
-// 	...
 };
 
+#define SRAM_BASE 0x20000000
+#define STUB_BUFFER_BASE ALIGN(SRAM_BASE + sizeof(stm32f4_flash_write_stub), 4)
+
 bool stm32f4_probe(struct target_s *target)
 {
 	uint32_t idcode;
@@ -239,34 +208,19 @@ static int stm32f4_flash_write(struct target_s *target, uint32_t dest,
                                const uint8_t *src, size_t len)
 {
 	uint32_t offset = dest % 4;
-	uint32_t words = (offset + len + 3) / 4;
+	uint8_t data[ALIGN(offset + len, 4)];
-	uint32_t data[2 + words];
-	uint16_t sr;
 
 	/* Construct data buffer used by stub */
-	data[0] = dest - offset;
+	/* pad partial words with all 1s to avoid damaging overlapping areas */
-	data[1] = words * 4;		/* length must always be a multiple of 4 */
+	memset(data, 0xff, sizeof(data));
-	data[2] = 0xFFFFFFFF;		/* pad partial words with all 1s to avoid */
+	memcpy((uint8_t *)data + offset, src, len);
-	data[words + 1] = 0xFFFFFFFF;	/* damaging overlapping areas */
-	memcpy((uint8_t *)&data[2] + offset, src, len);
 
-	/* Write stub and data to target ram and set PC */
+	/* Write buffer to target ram call stub */
-	target_mem_write(target, 0x20000000, stm32f4_flash_write_stub, 0x30);
+	target_mem_write(target, STUB_BUFFER_BASE, data, sizeof(data));
-	target_mem_write(target, 0x20000030, data, sizeof(data));
+	return cortexm_run_stub(target, SRAM_BASE, stm32f4_flash_write_stub,
-	target_pc_write(target, 0x20000000);
+	                        sizeof(stm32f4_flash_write_stub),
-	if(target_check_error(target))
+	                        dest - offset, STUB_BUFFER_BASE, sizeof(data),
-		return -1;
+	                        0);
-
-	/* Execute the stub */
-	target_halt_resume(target, 0);
-	while(!target_halt_wait(target));
-
-	/* Check for error */
-	sr = target_mem_read32(target, FLASH_SR);
-	if(sr & SR_ERROR_MASK)
-		return -1;
-
-	return 0;
 }
 
 static bool stm32f4_cmd_erase_mass(target *t)