Merge pull request #223 from gsmcmullin/nrf51_c_stub

nrf51: Replace stub with C version and pass params in registers

src/target/flashstub/nrf51.c

@@ -0,0 +1,37 @@
+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2017  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 <stdint.h>
+#include "stub.h"
+
+/* Non-Volatile Memory Controller (NVMC) Registers */
+#define NVMC           ((volatile uint32_t *)0x4001E000)
+#define NVMC_READY     NVMC[0x100]
+
+void __attribute__((naked))
+nrf51_flash_write_stub(volatile uint32_t *dest, uint32_t *src, uint32_t size)
+{
+	for (int i; i < size; i += 4) {
+		*dest++ = *src++;
+		while (!(NVMC_READY & 1))
+			;
+	}
+
+	stub_exit(0);
+}

src/target/flashstub/nrf51.s

@@ -1,40 +0,0 @@
-.global _start
-
-_start:
-	ldr r0, _ready
-	ldr r1, _addr
-	mov r2, pc
-	add r2, #(_data - . - 2)
-	ldr r3, _size
-_next:
-	cmp r3, #0
-	beq _done
-	@ Write data to flash
-	ldr r4, [r2]
-	str r4, [r1]
-
-_wait:	@ Wait for READY bit
-	ldr r4, [r0]
-	mov r6, #1
-	tst r4, r6
-	beq _wait
-
-	sub r3, #4
-	add r1, #4
-	add r2, #4
-	b _next
-_done:
-	bkpt
-
-@.align 4
-.org 0x24
-_ready:
-	.word 0x4001E400
-_addr:
-	.word 0
-_size:
-	.word 12
-_data:
-	.word 0xAAAAAAAA
-	.word 0xBBBBBBBB
-	.word 0xCCCCCCCC

src/target/flashstub/nrf51.stub

@@ -1 +1 @@
-0x4808, 0x4909, 0x467A, 0x3228, 0x4B08, 0x2B00, 0xD009, 0x6814, 0x600C, 0x6804, 0x2601, 0x4234, 0xD0FB, 0x3B04, 0x3104, 0x3204, 0xE7F3, 0xBE00, 0xE400, 0x4001, 0x0000, 0x0000, 0x000C, 0x0000, 0xAAAA, 0xAAAA, 0xBBBB, 0xBBBB, 0xCCCC, 0xCCCC,
+0x2300, 0x2601, 0x4D06, 0x1AC9, 0x18C4, 0x429A, 0xD800, 0xBE00, 0x58CF, 0x6027, 0x682C, 0x4234, 0xD0FC, 0x3304, 0xE7F4, 0x46C0, 0xE400, 0x4001, 

src/target/nrf51.c

@@ -82,7 +82,7 @@ const struct command_s nrf51_read_cmd_list[] = {
 #define NRF52_PAGE_SIZE 4096
 
 #define SRAM_BASE          0x20000000
-#define STUB_BUFFER_BASE   (SRAM_BASE + 0x28)
+#define STUB_BUFFER_BASE   ALIGN(SRAM_BASE + sizeof(nrf51_flash_write_stub), 4)
 
 static const uint16_t nrf51_flash_write_stub[] = {
 #include "flashstub/nrf51.stub"
@@ -219,14 +219,6 @@ static int nrf51_flash_write(struct target_flash *f,
                              target_addr dest, const void *src, size_t len)
 {
 	target *t = f->t;
-	uint32_t data[2 + len/4];
-
-	/* FIXME rewrite stub to use register args */
-
-	/* Construct data buffer used by stub */
-	data[0] = dest;
-	data[1] = len;		/* length must always be a multiple of 4 */
-	memcpy((uint8_t *)&data[2], src, len);
 
 	/* Enable write */
 	target_mem_write32(t, NRF51_NVMC_CONFIG, NRF51_NVMC_CONFIG_WEN);
@@ -239,13 +231,13 @@ static int nrf51_flash_write(struct target_flash *f,
 	/* Write stub and data to target ram and call stub */
 	target_mem_write(t, SRAM_BASE, nrf51_flash_write_stub,
 	                 sizeof(nrf51_flash_write_stub));
-	target_mem_write(t, STUB_BUFFER_BASE, data, len + 8);
+	target_mem_write(t, STUB_BUFFER_BASE, src, len);
-	cortexm_run_stub(t, SRAM_BASE, 0, 0, 0, 0);
+	int ret = cortexm_run_stub(t, SRAM_BASE, dest,
-
+	                           STUB_BUFFER_BASE, len, 0);
 	/* Return to read-only */
 	target_mem_write32(t, NRF51_NVMC_CONFIG, NRF51_NVMC_CONFIG_REN);
 
-	return 0;
+	return ret;
 }
 
 static bool nrf51_cmd_erase_all(target *t)
@@ -332,4 +324,3 @@ static bool nrf51_cmd_read(target *t, int argc, const char *argv[])
 
 	return nrf51_cmd_read_help(t);
 }
-