Rewrote stm32f1 stub in C and call with parameters in registers.

flashstub/Makefile

@@ -11,7 +11,11 @@ endif
 CFLAGS=-mcpu=cortex-m3 -mthumb -I../libopencm3/include
 ASFLAGS=-mcpu=cortex-m3 -mthumb
 
-all:	lmi.stub stm32.stub stm32f4.stub nrf51.stub
+all:	lmi.stub stm32f4.stub nrf51.stub stm32f1.stub
+
+stm32f1.o: stm32f1.c
+	$(Q)echo "  CC      $<"
+	$(Q)$(CC) $(CFLAGS) -DSTM32F1 -o $@ -c $<
 
 %.o:	%.s
 	$(Q)echo "  AS      $<"

flashstub/stm32.s

@@ -1,43 +0,0 @@
-.global _start
-
-_start:
-	ldr r0, _flashbase
-	ldr r1, _addr
-	mov r2, pc
-	add r2, #(_data - . - 2)
-	ldr r3, _size
-	mov r5, #1
-_next:
-	cmp r3, #0
-	beq _done
-	@ Write PG command to FLASH_CR
-	str r5, [r0, #0x10]
-	@ Write data to flash (half-word)
-	ldrh r4, [r2]
-	strh r4, [r1]
-
-_wait:	@ Wait for BSY bit to clear
-	ldr r4, [r0, #0x0C]
-	mov r6, #1
-	tst r4, r6
-	bne _wait
-
-	sub r3, #2
-	add r1, #2
-	add r2, #2
-	b _next
-_done:
-	bkpt
-
-@.align 4
-.org 0x28
-_flashbase:
-	.word 0x40022000
-_addr:
-	.word 0
-_size:
-	.word 12
-_data:
-	.word 0xAAAAAAAA
-	.word 0xBBBBBBBB
-	.word 0xCCCCCCCC

flashstub/stm32.stub

@@ -1 +0,0 @@
-0x4809, 0x490A, 0x467A, 0x322C, 0x4B09, 0x2501, 0x2B00, 0xD00A, 0x6105, 0x8814, 0x800C, 0x68C4, 0x2601, 0x4234, 0xD1FB, 0x3B02, 0x3102, 0x3202, 0xE7F2, 0xBE00, 0x2000, 0x4002, 0x0000, 0x0000, 0x000C, 0x0000, 0xAAAA, 0xAAAA, 0xBBBB, 0xBBBB, 0xCCCC, 0xCCCC, 

flashstub/stm32f1.c

@@ -0,0 +1,34 @@
+/*
+ * 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"
+
+void __attribute__((naked))
+stm32f1_flash_write_stub(uint16_t *dest, uint16_t *src, uint32_t size)
+{
+	while (size) {
+		FLASH_CR = FLASH_CR_PG;
+		*dest++ = *src++;
+		size -= 2;
+		while (FLASH_SR & FLASH_SR_BSY)
+			;
+	}
+	asm("bkpt");
+}
+

flashstub/stm32f1.stub

@@ -0,0 +1 @@
+0x4613, 0xE010, 0x4A09, 0x2401, 0x6014, 0x4602, 0x1C90, 0x460C, 0x1CA1, 0x8824, 0x8014, 0x3B02, 0xBF00, 0x4A05, 0x6812, 0xF002, 0x0201, 0x2A00, 0xD1F9, 0x2B00, 0xD1EC, 0xBE00, 0x2010, 0x4002, 0x200C, 0x4002, 

src/include/general.h

@@ -38,5 +38,7 @@
 #define DEBUG	printf
 #endif
 
+#define ALIGN(x, n) (((x) + (n) - 1) & ~((n) - 1))
+
 #endif
 

src/stm32f1.c

@@ -36,8 +36,6 @@
 #include "command.h"
 #include "gdb_packet.h"
 
-#define SRAM_BASE 0x20000000
-
 static bool stm32f1_cmd_erase_mass(target *t);
 static bool stm32f1_cmd_option(target *t, int argc, char *argv[]);
 
@@ -123,9 +121,12 @@ static const char stm32hd_xml_memory_map[] = "<?xml version=\"1.0\"?>"
 #define DBGMCU_IDCODE_F0	0x40015800
 
 static const uint16_t stm32f1_flash_write_stub[] = {
-#include "../flashstub/stm32.stub"
+#include "../flashstub/stm32f1.stub"
 };
 
+#define SRAM_BASE 0x20000000
+#define STUB_BUFFER_BASE ALIGN(SRAM_BASE + sizeof(stm32f1_flash_write_stub), 4)
+
 bool stm32f1_probe(struct target_s *target)
 {
 	target->idcode = target_mem_read32(target, DBGMCU_IDCODE) & 0xfff;
@@ -247,22 +248,18 @@ static int stm32f1_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;
-	if (words > 256)
-		return -1;
-	uint32_t data[2 + words];
+	uint8_t data[ALIGN(offset + len, 4)];
 
 	/* Construct data buffer used by stub */
-	data[0] = dest - offset;
-	data[1] = words * 4;		/* length must always be a multiple of 4 */
-	data[2] = 0xFFFFFFFF;		/* pad partial words with all 1s to avoid */
-	data[words + 1] = 0xFFFFFFFF;	/* damaging overlapping areas */
-	memcpy((uint8_t *)&data[2] + offset, src, len);
+	/* pad partial words with all 1s to avoid damaging overlapping areas */
+	memset(data, 0xff, sizeof(data));
+	memcpy((uint8_t *)data + offset, src, len);
 
 	/* Write stub and data to target ram and set PC */
-	target_mem_write(target, 0x2000002C, data, sizeof(data));
-	cortexm_run_stub(target, SRAM_BASE, stm32f1_flash_write_stub, 0x2C,
-	                 0, 0, 0, 0);
+	target_mem_write(target, STUB_BUFFER_BASE, data, sizeof(data));
+	cortexm_run_stub(target, SRAM_BASE, stm32f1_flash_write_stub,
+	                sizeof(stm32f1_flash_write_stub),
+	                dest - offset, STUB_BUFFER_BASE, sizeof(data), 0);
 
 	/* Check for error */
 	if (target_mem_read32(target, FLASH_SR) & SR_ERROR_MASK)