path: root/common/system_common.c

/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/* System module for Chrome EC : common functions */

#include "board.h"
#include "clock.h"
#include "console.h"
#include "flash.h"
#include "gpio.h"
#include "hooks.h"
#include "host_command.h"
#include "lpc.h"
#include "ec_commands.h"
#include "system.h"
#include "task.h"
#include "uart.h"
#include "util.h"
#include "version.h"

/* Console output macros */
#define CPUTS(outstr) cputs(CC_SYSTEM, outstr)
#define CPRINTF(format, args...) cprintf(CC_SYSTEM, format, ## args)

struct jump_tag {
	uint16_t tag;
	uint8_t data_size;
	uint8_t data_version;
};


/* Data passed between the current image and the next one when jumping between
 * images. */
#define JUMP_DATA_MAGIC 0x706d754a  /* "Jump" */
#define JUMP_DATA_VERSION 3
#define JUMP_DATA_SIZE_V2 16  /* Size of version 2 jump data struct */
struct jump_data {
	/* Add new fields to the _start_ of the struct, since we copy it to the
	 * _end_ of RAM between images.  This way, the magic number will always
	 * be the last word in RAM regardless of how many fields are added. */

	/* Fields from version 3 */
	uint8_t recovery_required; /* Signal recovery mode to BIOS */
	int struct_size;           /* Size of struct jump_data */

	/* Fields from version 2 */
	int jump_tag_total;  /* Total size of all jump tags */

	/* Fields from version 1 */
	int reset_cause;     /* Reset cause for the previous boot */
	int version;         /* Version (JUMP_DATA_VERSION) */
	int magic;           /* Magic number (JUMP_DATA_MAGIC).  If this
			      * doesn't match at pre-init time, assume no valid
			      * data from the previous image. */
};

/* Jump data goes at the end of RAM */
static struct jump_data * const jdata =
	(struct jump_data *)(CONFIG_RAM_BASE + CONFIG_RAM_SIZE
			     - sizeof(struct jump_data));

static const char * const image_names[] = {"unknown", "RO", "A", "B"};
static enum system_reset_cause_t reset_cause = SYSTEM_RESET_UNKNOWN;
static int jumped_to_image;
static int disable_jump;


int system_is_locked(void)
{
#ifdef CONFIG_SYSTEM_UNLOCKED
	/* System is explicitly unlocked */
	return 0;

#elif defined(BOARD_link) && defined(CONFIG_FLASH)
	/* On link, unlocked if write protect pin deasserted or flash protect
	 * lock not applied. */
	int lock = flash_get_protect_lock();
	if (!(lock & FLASH_PROTECT_PIN_ASSERTED) ||
	    !(lock & FLASH_PROTECT_LOCK_APPLIED))
		return 0;

	/* If WP pin is asserted and lock is applied, we're locked */
	return 1;
#else
	/* Other configs are locked by default */
	return 1;
#endif
}


int system_usable_ram_end(void)
{
	/* Leave space at the end of RAM for jump data and tags.
	 *
	 * Note that jump_tag_total is 0 on a reboot, so we have the maximum
	 * amount of RAM available on a reboot; we only lose space for stored
	 * tags after a sysjump.  When verified boot runs after a reboot, it'll
	 * have as much RAM as we can give it; after verified boot jumps to
	 * another image there'll be less RAM, but we'll care less too. */
	return (uint32_t)jdata - jdata->jump_tag_total;
}


enum system_reset_cause_t system_get_reset_cause(void)
{
	return reset_cause;
}


int system_get_recovery_required(void)
{
	return jdata->recovery_required;
}


int system_jumped_to_this_image(void)
{
	return jumped_to_image;
}


int system_add_jump_tag(uint16_t tag, int version, int size, const void *data)
{
	struct jump_tag *t;

	/* Only allowed during a sysjump */
	if (jdata->magic != JUMP_DATA_MAGIC)
		return EC_ERROR_UNKNOWN;

	/* Make room for the new tag */
	if (size > 255 || (size & 3))
		return EC_ERROR_INVAL;
	jdata->jump_tag_total += size + sizeof(struct jump_tag);

	t = (struct jump_tag *)system_usable_ram_end();
	t->tag = tag;
	t->data_size = size;
	t->data_version = version;
	if (size)
		memcpy(t + 1, data, size);

	return EC_SUCCESS;
}

const uint8_t *system_get_jump_tag(uint16_t tag, int *version, int *size)
{
	const struct jump_tag *t;
	int used = 0;

	/* Search through tag data for a match */
	while (used < jdata->jump_tag_total) {
		/* Check the next tag */
		t = (const struct jump_tag *)(system_usable_ram_end() + used);
		used += sizeof(struct jump_tag) + t->data_size;
		if (t->tag != tag)
			continue;

		/* Found a match */
		if (size)
			*size = t->data_size;
		if (version)
			*version = t->data_version;

		return (const uint8_t *)(t + 1);
	}

	/* If we're still here, no match */
	return NULL;
}


void system_set_reset_cause(enum system_reset_cause_t cause)
{
	reset_cause = cause;
}


void system_disable_jump(void)
{
	disable_jump = 1;
}


const char *system_get_reset_cause_string(void)
{
	static const char * const cause_descs[] = {
		"unknown", "other", "brownout", "power-on", "reset pin",
		"soft", "watchdog", "rtc alarm", "wake pin", "low battery"};

	return reset_cause < ARRAY_SIZE(cause_descs) ?
			cause_descs[reset_cause] : "?";
}


enum system_image_copy_t system_get_image_copy(void)
{
	uint32_t my_addr = (uint32_t)system_get_image_copy - CONFIG_FLASH_BASE;

	if (my_addr >= CONFIG_SECTION_RO_OFF &&
	    my_addr < (CONFIG_SECTION_RO_OFF + CONFIG_SECTION_RO_SIZE))
		return SYSTEM_IMAGE_RO;

	if (my_addr >= CONFIG_SECTION_A_OFF &&
	    my_addr < (CONFIG_SECTION_A_OFF + CONFIG_SECTION_A_SIZE))
		return SYSTEM_IMAGE_RW_A;

	if (my_addr >= CONFIG_SECTION_B_OFF &&
	    my_addr < (CONFIG_SECTION_B_OFF + CONFIG_SECTION_B_SIZE))
		return SYSTEM_IMAGE_RW_B;

	return SYSTEM_IMAGE_UNKNOWN;
}


/* Returns true if the given range is overlapped with the active image.
 *
 * We only care the runtime code since the EC is running over it.
 * We don't care about the vector table, FMAP, and init code. */
int system_unsafe_to_overwrite(uint32_t offset, uint32_t size) {
	uint32_t r_offset;
	uint32_t r_size;

	switch (system_get_image_copy()) {
	case SYSTEM_IMAGE_RO:
		r_offset = CONFIG_FW_RO_OFF;
		r_size = CONFIG_FW_RO_SIZE;
		break;
	case SYSTEM_IMAGE_RW_A:
		r_offset = CONFIG_FW_A_OFF;
		r_size = CONFIG_FW_A_SIZE;
		break;
	case SYSTEM_IMAGE_RW_B:
		r_offset = CONFIG_FW_B_OFF;
		r_size = CONFIG_FW_B_SIZE;
		break;
	default:
		return 0;
	}

	if ((offset >= r_offset && offset < (r_offset + r_size)) ||
	    (r_offset >= offset && r_offset < (offset + size)))
		return 1;
	else
		return 0;
}


const char *system_get_image_copy_string(void)
{
	int copy = system_get_image_copy();
	return copy < ARRAY_SIZE(image_names) ? image_names[copy] : "?";
}


/* Jump to what we hope is the init address of an image.  This function does
 * not return. */
static void jump_to_image(uint32_t init_addr,
			  int recovery_required)
{
	void (*resetvec)(void) = (void(*)(void))init_addr;

#ifdef BOARD_link
	/*
	 * Jumping to any image asserts the signal to the Silego chip that that
	 * EC is not in read-only firmware.  (This is not technically true if
	 * jumping from RO -> RO, but that's not a meaningful use case...)
	 */
	gpio_set_level(GPIO_ENTERING_RW, 1);
#endif

	/* Flush UART output unless the UART hasn't been initialized yet */
	if (uart_init_done())
		uart_flush_output();

	/* Disable interrupts before jump */
	interrupt_disable();

	/* Fill in preserved data between jumps */
	jdata->recovery_required = recovery_required != 0;
	jdata->magic = JUMP_DATA_MAGIC;
	jdata->version = JUMP_DATA_VERSION;
	jdata->reset_cause = reset_cause;
	jdata->jump_tag_total = 0;  /* Reset tags */
	jdata->struct_size = sizeof(struct jump_data);

	/* Call other hooks; these may add tags */
	hook_notify(HOOK_SYSJUMP, 0);

	/* Jump to the reset vector */
	resetvec();
}


/* Return the base pointer for the image copy, or 0xffffffff if error. */
static uint32_t get_base(enum system_image_copy_t copy)
{
	switch (copy) {
	case SYSTEM_IMAGE_RO:
		return CONFIG_FLASH_BASE + CONFIG_FW_RO_OFF;
	case SYSTEM_IMAGE_RW_A:
		return CONFIG_FLASH_BASE + CONFIG_FW_A_OFF;
#ifndef CONFIG_NO_RW_B
	case SYSTEM_IMAGE_RW_B:
		return CONFIG_FLASH_BASE + CONFIG_FW_B_OFF;
#endif
	default:
		return 0xffffffff;
	}
}

/* Return the size of the image copy, or 0 if error. */
static uint32_t get_size(enum system_image_copy_t copy)
{
	switch (copy) {
	case SYSTEM_IMAGE_RO:
		return CONFIG_FW_RO_SIZE;
	case SYSTEM_IMAGE_RW_A:
		return CONFIG_FW_A_SIZE;
#ifndef CONFIG_NO_RW_B
	case SYSTEM_IMAGE_RW_B:
		return CONFIG_FW_B_SIZE;
#endif
	default:
		return 0;
	}
}


int system_run_image_copy(enum system_image_copy_t copy,
			  int recovery_required)
{
	uint32_t base;
	uint32_t init_addr;

	if (system_is_locked()) {
		/* System is locked, so disallow jumping between images unless
		 * this is the initial jump from RO to RW code. */

		/* Must currently be running the RO image */
		if (system_get_image_copy() != SYSTEM_IMAGE_RO)
			return EC_ERROR_ACCESS_DENIED;

		/* Target image must be RW image */
		if (copy != SYSTEM_IMAGE_RW_A && copy != SYSTEM_IMAGE_RW_B)
			return EC_ERROR_ACCESS_DENIED;

		/* Can't have already jumped between images */
		if (jumped_to_image)
			return EC_ERROR_ACCESS_DENIED;

		/* Jumping must still be enabled */
		if (disable_jump)
			return EC_ERROR_ACCESS_DENIED;
	}

	/* Load the appropriate reset vector */
	base = get_base(copy);
	if (base == 0xffffffff)
		return EC_ERROR_INVAL;

	/* Make sure the reset vector is inside the destination image */
	init_addr = *(uint32_t *)(base + 4);
	if (init_addr < base || init_addr >= base + get_size(copy))
		return EC_ERROR_UNKNOWN;

	CPRINTF("[%T Jumping to image %s]\n", image_names[copy]);

	jump_to_image(init_addr, recovery_required);

	/* Should never get here */
	return EC_ERROR_UNKNOWN;
}


const char *system_get_version(enum system_image_copy_t copy)
{
	uint32_t addr;
	const struct version_struct *v;

	/* Handle version of current image */
	if (copy == system_get_image_copy() || copy == SYSTEM_IMAGE_UNKNOWN)
		return version_data.version;

	addr = get_base(copy);
	if (addr == 0xffffffff)
		return "";

	/* The version string is always located after the reset vectors, so
	 * it's the same as in the current image. */
	addr += ((uint32_t)&version_data - get_base(system_get_image_copy()));

	/* Make sure the version struct cookies match before returning the
	 * version string. */
	v = (const struct version_struct *)addr;
	if (v->cookie1 == version_data.cookie1 &&
	    v->cookie2 == version_data.cookie2)
		return v->version;

	return "";
}


int system_get_board_version(void)
{
	int v = 0;

#ifdef BOARD_link
	/* Drive board revision GPIOs as outputs briefly.  This clears any
	 * charge on the proto1 test points, since proto1 doesn't have
	 * stuffing resistors. */
	/* TODO: (crosbug.com/p/9559) remove when proto1 has been superseded by
	 * EVT */
	gpio_set_flags(GPIO_BOARD_VERSION1, GPIO_OUTPUT);
	gpio_set_flags(GPIO_BOARD_VERSION2, GPIO_OUTPUT);
	gpio_set_flags(GPIO_BOARD_VERSION3, GPIO_OUTPUT);
	gpio_set_level(GPIO_BOARD_VERSION1, 0);
	gpio_set_level(GPIO_BOARD_VERSION2, 0);
	gpio_set_level(GPIO_BOARD_VERSION3, 0);
	clock_wait_cycles(20);
	gpio_set_flags(GPIO_BOARD_VERSION1, GPIO_INPUT);
	gpio_set_flags(GPIO_BOARD_VERSION2, GPIO_INPUT);
	gpio_set_flags(GPIO_BOARD_VERSION3, GPIO_INPUT);
	clock_wait_cycles(20);

	if (gpio_get_level(GPIO_BOARD_VERSION1))
		v |= 0x01;
	if (gpio_get_level(GPIO_BOARD_VERSION2))
		v |= 0x02;
	if (gpio_get_level(GPIO_BOARD_VERSION3))
		v |= 0x04;
#endif

	return v;
}


const char *system_get_build_info(void)
{
	return build_info;
}


int system_common_pre_init(void)
{
	/* Check jump data if this is a jump between images.  Jumps all show up
	 * as an unknown reset reason, because we jumped directly from one
	 * image to another without actually triggering a chip reset. */
	if (jdata->magic == JUMP_DATA_MAGIC &&
	    jdata->version >= 1 &&
	    reset_cause == SYSTEM_RESET_UNKNOWN) {
		int delta;       /* Change in jump data struct size between the
				  * previous image and this one. */

		/* Yes, we jumped to this image */
		jumped_to_image = 1;
		/* Overwrite the reset cause with the real one */
		reset_cause = jdata->reset_cause;

		/* If the jump data structure isn't the same size as the
		 * current one, shift the jump tags to immediately before the
		 * current jump data structure, to make room for initalizing
		 * the new fields below. */
		if (jdata->version == 1)
			delta = 0;  /* No tags in v1, so no need for move */
		else if (jdata->version == 2)
			delta = sizeof(struct jump_data) - JUMP_DATA_SIZE_V2;
		else
			delta = sizeof(struct jump_data) - jdata->struct_size;

		if (delta && jdata->jump_tag_total) {
			uint8_t *d = (uint8_t *)system_usable_ram_end();
			memmove(d, d + delta, jdata->jump_tag_total);
		}

		/* Initialize fields added after version 1 */
		if (jdata->version < 2)
			jdata->jump_tag_total = 0;

		/* Initialize fields added after version 2 */
		if (jdata->version < 3)
			jdata->recovery_required = 0;

		/* Struct size is now the current struct size */
		jdata->struct_size = sizeof(struct jump_data);

		/* Clear the jump struct's magic number.  This prevents
		 * accidentally detecting a jump when there wasn't one, and
		 * disallows use of system_add_jump_tag(). */
		jdata->magic = 0;
	} else {
		/* Clear the whole jump_data struct */
		memset(jdata, 0, sizeof(struct jump_data));
	}

	return EC_SUCCESS;
}

/*****************************************************************************/
/* Console commands */

static int command_sysinfo(int argc, char **argv)
{
	ccprintf("Last reset: %d (%s)\n",
		    system_get_reset_cause(),
		    system_get_reset_cause_string());
	ccprintf("Copy:   %s\n", system_get_image_copy_string());
	ccprintf("Jumped: %s\n", system_jumped_to_this_image() ? "yes" : "no");
	ccprintf("Locked: %s\n", system_is_locked() ? "yes" : "no");
	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(sysinfo, command_sysinfo,
			NULL,
			"Print system info",
			NULL);


#ifdef CONSOLE_COMMAND_SCRATCHPAD
static int command_scratchpad(int argc, char **argv)
{
	int rv = EC_SUCCESS;

	if (argc == 2) {
		char *e;
		int s = strtoi(argv[1], &e, 0);
		if (*e)
			return EC_ERROR_PARAM1;
		rv = system_set_scratchpad(s);
	}

	ccprintf("Scratchpad: 0x%08x\n", system_get_scratchpad());
	return rv;
}
DECLARE_CONSOLE_COMMAND(scratchpad, command_scratchpad,
			"[val]",
			"Get or set scratchpad value",
			NULL);
#endif


static int command_hibernate(int argc, char **argv)
{
	int seconds;
	int microseconds = 0;

	if (argc < 2)
		return EC_ERROR_PARAM_COUNT;
	seconds = strtoi(argv[1], NULL, 0);
	if (argc >= 3)
		microseconds = strtoi(argv[2], NULL, 0);

	ccprintf("Hibernating for %d.%06d s\n", seconds, microseconds);
	cflush();

	system_hibernate(seconds, microseconds);

	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(hibernate, command_hibernate,
			"sec [usec]",
			"Hibernate the EC",
			NULL);


static int command_version(int argc, char **argv)
{
	ccprintf("Chip:  %s %s %s\n", system_get_chip_vendor(),
		 system_get_chip_name(), system_get_chip_revision());
	ccprintf("Board: %d\n", system_get_board_version());
	ccprintf("RO:    %s\n", system_get_version(SYSTEM_IMAGE_RO));
	ccprintf("RW-A:  %s\n", system_get_version(SYSTEM_IMAGE_RW_A));
	ccprintf("RW-B:  %s\n", system_get_version(SYSTEM_IMAGE_RW_B));
	ccprintf("Build: %s\n", system_get_build_info());
	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(version, command_version,
			NULL,
			"Print versions",
			NULL);


static int command_sysjump(int argc, char **argv)
{
	uint32_t addr;
	char *e;

	/* Command is only allowed on an unlocked system */
	if (system_is_locked())
		return EC_ERROR_ACCESS_DENIED;

	if (argc < 2)
		return EC_ERROR_PARAM_COUNT;

	ccputs("Processing sysjump command\n");

	/* Handle named images */
	if (!strcasecmp(argv[1], "RO"))
		return system_run_image_copy(SYSTEM_IMAGE_RO, 0);
	else if (!strcasecmp(argv[1], "A"))
		return system_run_image_copy(SYSTEM_IMAGE_RW_A, 0);
	else if (!strcasecmp(argv[1], "B"))
		return system_run_image_copy(SYSTEM_IMAGE_RW_B, 0);

	/* Check for arbitrary address */
	addr = strtoi(argv[1], &e, 0);
	if (*e)
		return EC_ERROR_PARAM1;

	ccprintf("Jumping to 0x%08x\n", addr);
	cflush();
	jump_to_image(addr, 0);
	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(sysjump, command_sysjump,
			"[RO | A | B | addr]",
			"Jump to a system image or address",
			NULL);


static int command_reboot(int argc, char **argv)
{
	int is_hard = 0;

	if (argc == 2 && !strcasecmp(argv[1], "hard")) {
		ccputs("Hard-");
		is_hard = 1;
	}

	ccputs("Rebooting!\n\n\n");
	cflush();
	system_reset(is_hard);
	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(reboot, command_reboot,
			"[hard]",
			"Reboot the EC",
			NULL);

/*****************************************************************************/
/* Host commands */

static int host_command_get_version(uint8_t *data, int *resp_size)
{
	struct ec_response_get_version *r =
			(struct ec_response_get_version *)data;

	strzcpy(r->version_string_ro, system_get_version(SYSTEM_IMAGE_RO),
		sizeof(r->version_string_ro));
	strzcpy(r->version_string_rw_a, system_get_version(SYSTEM_IMAGE_RW_A),
		sizeof(r->version_string_rw_a));
	strzcpy(r->version_string_rw_b, system_get_version(SYSTEM_IMAGE_RW_B),
		sizeof(r->version_string_rw_b));

	switch (system_get_image_copy()) {
	case SYSTEM_IMAGE_RO:
		r->current_image = EC_IMAGE_RO;
		break;
	case SYSTEM_IMAGE_RW_A:
		r->current_image = EC_IMAGE_RW_A;
		break;
	case SYSTEM_IMAGE_RW_B:
		r->current_image = EC_IMAGE_RW_B;
		break;
	default:
		r->current_image = EC_IMAGE_UNKNOWN;
		break;
	}

	*resp_size = sizeof(struct ec_response_get_version);
	return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_GET_VERSION, host_command_get_version);


static int host_command_build_info(uint8_t *data, int *resp_size)
{
	struct ec_response_get_build_info *r =
			(struct ec_response_get_build_info *)data;

	strzcpy(r->build_string, system_get_build_info(),
		sizeof(r->build_string));

	*resp_size = sizeof(struct ec_response_get_build_info);
	return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_GET_BUILD_INFO, host_command_build_info);


static int host_command_get_chip_info(uint8_t *data, int *resp_size)
{
	struct ec_response_get_chip_info *r =
			(struct ec_response_get_chip_info *)data;

	strzcpy(r->vendor, system_get_chip_vendor(), sizeof(r->vendor));
	strzcpy(r->name, system_get_chip_name(), sizeof(r->name));
	strzcpy(r->revision, system_get_chip_revision(), sizeof(r->revision));

	*resp_size = sizeof(struct ec_response_get_chip_info);
	return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_GET_CHIP_INFO, host_command_get_chip_info);


int host_command_get_board_version(uint8_t *data, int *resp_size)
{
	struct ec_params_board_version *board_v =
			(struct ec_params_board_version *) data;

	board_v->board_version = (uint16_t) system_get_board_version();

	*resp_size = sizeof(struct ec_params_board_version);
	return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_GET_BOARD_VERSION, host_command_get_board_version);


int host_command_reboot(uint8_t *data, int *resp_size)
{
	enum system_image_copy_t copy;
	struct ec_params_reboot_ec *p =	(struct ec_params_reboot_ec *)data;
	int recovery_request = p->reboot_flags & EC_CMD_REBOOT_BIT_RECOVERY;

	/* This command is only allowed on unlocked systems, because jumping
	 * directly to another image bypasses verified boot. */
	if (system_is_locked())
		return EC_RES_ACCESS_DENIED;

	switch (p->target) {
	case EC_IMAGE_RO:
		copy = SYSTEM_IMAGE_RO;
		break;
	case EC_IMAGE_RW_A:
		copy = SYSTEM_IMAGE_RW_A;
		break;
	case EC_IMAGE_RW_B:
		copy = SYSTEM_IMAGE_RW_B;
		break;
	default:
		return EC_RES_ERROR;
	}

#ifdef CONFIG_TASK_HOSTCMD
#ifdef CONFIG_LPC
	/* Clean busy bits on host */
	host_send_result(0, EC_RES_SUCCESS);
	host_send_result(1, EC_RES_SUCCESS);
#elif defined CONFIG_I2C
	host_send_result(0, EC_RES_SUCCESS);
#endif
#endif

	CPUTS("[Executing host reboot command]\n");
	system_run_image_copy(copy, recovery_request);

	/* We normally never get down here, because we'll have jumped to
	 * another image.  To confirm this command worked, the host will need
	 * to check what image is current using GET_VERSION.
	 *
	 * If we DO get down here, something went wrong in the reboot, so
	 * return error. */
	return EC_RES_ERROR;
}
DECLARE_HOST_COMMAND(EC_CMD_REBOOT_EC, host_command_reboot);