blackmagic/src/target/lpc43xx.c

/*
 * This file is part of the Black Magic Debug project.
 *
 * Copyright (C) 2014 Allen Ibara <aibara>
 * Copyright (C) 2015 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 "general.h"
#include "target.h"
#include "target_internal.h"
#include "cortexm.h"
#include "lpc_common.h"

#define LPC43XX_CHIPID	0x40043200

#define IAP_ENTRYPOINT_LOCATION	0x10400100

#define LPC43XX_ETBAHB_SRAM_BASE 0x2000C000
#define LPC43XX_ETBAHB_SRAM_SIZE (16*1024)

#define LPC43XX_WDT_MODE 0x40080000
#define LPC43XX_WDT_CNT  0x40080004
#define LPC43XX_WDT_FEED 0x40080008
#define LPC43XX_WDT_PERIOD_MAX 0xFFFFFF
#define LPC43XX_WDT_PROTECT (1 << 4)

#define IAP_RAM_SIZE	LPC43XX_ETBAHB_SRAM_SIZE
#define IAP_RAM_BASE	LPC43XX_ETBAHB_SRAM_BASE

#define IAP_PGM_CHUNKSIZE	4096

#define FLASH_NUM_BANK		2
#define FLASH_NUM_SECTOR	15

static bool lpc43xx_cmd_erase(target *t, int argc, const char *argv[]);
static bool lpc43xx_cmd_reset(target *t, int argc, const char *argv[]);
static bool lpc43xx_cmd_mkboot(target *t, int argc, const char *argv[]);
static int lpc43xx_flash_init(target *t);
static int lpc43xx_flash_erase(struct target_flash *f, target_addr addr, size_t len);
static void lpc43xx_set_internal_clock(target *t);
static void lpc43xx_wdt_set_period(target *t);
static void lpc43xx_wdt_pet(target *t);

const struct command_s lpc43xx_cmd_list[] = {
	{"erase_mass", lpc43xx_cmd_erase, "Erase entire flash memory"},
	{"reset", lpc43xx_cmd_reset, "Reset target"},
	{"mkboot", lpc43xx_cmd_mkboot, "Make flash bank bootable"},
	{NULL, NULL, NULL}
};

void lpc43xx_add_flash(target *t, uint32_t iap_entry,
                       uint8_t bank, uint8_t base_sector,
                       uint32_t addr, size_t len, size_t erasesize)
{
	struct lpc_flash *lf = lpc_add_flash(t, addr, len);
	lf->f.erase = lpc43xx_flash_erase;
	lf->f.blocksize = erasesize;
	lf->f.buf_size = IAP_PGM_CHUNKSIZE;
	lf->bank = bank;
	lf->base_sector = base_sector;
	lf->iap_entry = iap_entry;
	lf->iap_ram = IAP_RAM_BASE;
	lf->iap_msp = IAP_RAM_BASE + IAP_RAM_SIZE;
	lf->wdt_kick = lpc43xx_wdt_pet;
}

bool lpc43xx_probe(target *t)
{
	uint32_t chipid;
	uint32_t iap_entry;

	chipid = target_mem_read32(t, LPC43XX_CHIPID);

	switch(chipid) {
	case 0x4906002B:	/* Parts with on-chip flash */
	case 0x7906002B:	/* LM43S?? - Undocumented? */
		switch (t->cpuid & 0xFF00FFF0) {
		case 0x4100C240:
			t->driver = "LPC43xx Cortex-M4";
			if (t->cpuid == 0x410FC241)
			{
				/* LPC4337 */
				iap_entry = target_mem_read32(t,
				                  IAP_ENTRYPOINT_LOCATION);
				target_add_ram(t, 0, 0x1A000000);
				lpc43xx_add_flash(t, iap_entry, 0, 0,
				                  0x1A000000, 0x10000, 0x2000);
				lpc43xx_add_flash(t, iap_entry, 0, 8,
				                  0x1A010000, 0x70000, 0x10000);
				target_add_ram(t, 0x1A080000, 0xF80000);
				lpc43xx_add_flash(t, iap_entry, 1, 0,
				                  0x1B000000, 0x10000, 0x2000);
				lpc43xx_add_flash(t, iap_entry, 1, 8,
				                  0x1B010000, 0x70000, 0x10000);
				target_add_commands(t, lpc43xx_cmd_list, "LPC43xx");
				target_add_ram(t, 0x1B080000, 0xE4F80000UL);
				t->target_options |= CORTEXM_TOPT_INHIBIT_SRST;
			}
			break;
		case 0x4100C200:
			t->driver = "LPC43xx Cortex-M0";
			break;
		default:
			t->driver = "LPC43xx <Unknown>";
		}
		return true;
	case 0x5906002B:	/* Flashless parts */
	case 0x6906002B:
		switch (t->cpuid & 0xFF00FFF0) {
		case 0x4100C240:
			t->driver = "LPC43xx Cortex-M4";
			break;
		case 0x4100C200:
			t->driver = "LPC43xx Cortex-M0";
			break;
		default:
			t->driver = "LPC43xx <Unknown>";
		}
		return true;
	}

	return false;
}

/* Reset all major systems _except_ debug */
static bool lpc43xx_cmd_reset(target *t, int argc, const char *argv[])
{
	(void)argc;
	(void)argv;

	/* Cortex-M4 Application Interrupt and Reset Control Register */
	static const uint32_t AIRCR = 0xE000ED0C;
	/* Magic value key */
	static const uint32_t reset_val = 0x05FA0004;

	/* System reset on target */
	target_mem_write(t, AIRCR, &reset_val, sizeof(reset_val));

	return true;
}

static bool lpc43xx_cmd_erase(target *t, int argc, const char *argv[])
{
	(void)argc;
	(void)argv;

	lpc43xx_flash_init(t);

	for (int bank = 0; bank < FLASH_NUM_BANK; bank++)
	{
		struct lpc_flash *f = (struct lpc_flash *)t->flash;
		if (lpc_iap_call(f, NULL, IAP_CMD_PREPARE,
		                 0, FLASH_NUM_SECTOR-1, bank))
			return false;

		if (lpc_iap_call(f, NULL, IAP_CMD_ERASE,
		                 0, FLASH_NUM_SECTOR-1, CPU_CLK_KHZ, bank))
			return false;
	}

	tc_printf(t, "Erase OK.\n");

	return true;
}

static int lpc43xx_flash_init(target *t)
{
	/* Deal with WDT */
	lpc43xx_wdt_set_period(t);

	/* Force internal clock */
	lpc43xx_set_internal_clock(t);

	/* Initialize flash IAP */
	struct lpc_flash *f = (struct lpc_flash *)t->flash;
	if (lpc_iap_call(f, NULL, IAP_CMD_INIT))
		return -1;

	return 0;
}

static int lpc43xx_flash_erase(struct target_flash *f, target_addr addr, size_t len)
{
	if (lpc43xx_flash_init(f->t))
		return -1;

	return lpc_flash_erase(f, addr, len);
}

static void lpc43xx_set_internal_clock(target *t)
{
	const uint32_t val2 = (1 << 11) | (1 << 24);
	target_mem_write32(t, 0x40050000 + 0x06C, val2);
}

/*
 * Call Boot ROM code to make a flash bank bootable by computing and writing the
 * correct signature into the exception table near the start of the bank.
 *
 * This is done indepently of writing to give the user a chance to verify flash
 * before changing it.
 */
static bool lpc43xx_cmd_mkboot(target *t, int argc, const char *argv[])
{
	/* Usage: mkboot 0 or mkboot 1 */
	if (argc != 2) {
		tc_printf(t, "Expected bank argument 0 or 1.\n");
		return false;
	}

	const long int bank = strtol(argv[1], NULL, 0);

	if ((bank != 0) && (bank != 1)) {
		tc_printf(t, "Unexpected bank number, should be 0 or 1.\n");
		return false;
	}

	lpc43xx_flash_init(t);

	/* special command to compute/write magic vector for signature */
	struct lpc_flash *f = (struct lpc_flash *)t->flash;
	if (lpc_iap_call(f, NULL, IAP_CMD_SET_ACTIVE_BANK, bank, CPU_CLK_KHZ)) {
		tc_printf(t, "Set bootable failed.\n");
		return false;
	}

	tc_printf(t, "Set bootable OK.\n");
	return true;
}

static void lpc43xx_wdt_set_period(target *t)
{
	/* Check if WDT is on */
	uint32_t wdt_mode = target_mem_read32(t, LPC43XX_WDT_MODE);

	/* If WDT on, we can't disable it, but we may be able to set a long period */
	if (wdt_mode && !(wdt_mode & LPC43XX_WDT_PROTECT))
		target_mem_write32(t, LPC43XX_WDT_CNT, LPC43XX_WDT_PERIOD_MAX);
}

static void lpc43xx_wdt_pet(target *t)
{
	/* Check if WDT is on */
	uint32_t wdt_mode = target_mem_read32(t, LPC43XX_WDT_MODE);

	/* If WDT on, pet */
	if (wdt_mode) {
		target_mem_write32(t, LPC43XX_WDT_FEED, 0xAA);
		target_mem_write32(t, LPC43XX_WDT_FEED, 0xFF);
	}
}