common/bootstage.c - u-boot-mtk - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2011, Google Inc. All rights reserved.
  */


 /*
  * This module records the progress of boot and arbitrary commands, and
  * permits accurate timestamping of each.
  */

 #include <common.h>
 #include <linux/libfdt.h>
 #include <malloc.h>
 #include <linux/compiler.h>

 DECLARE_GLOBAL_DATA_PTR;

 enum {
 	RECORD_COUNT = CONFIG_VAL(BOOTSTAGE_RECORD_COUNT),
 };

 struct bootstage_record {
 	ulong time_us;
 	uint32_t start_us;
 	const char *name;
 	int flags;		/* see enum bootstage_flags */
 	enum bootstage_id id;
 };

 struct bootstage_data {
 	uint rec_count;
 	uint next_id;
 	struct bootstage_record record[RECORD_COUNT];
 };

 enum {
 	BOOTSTAGE_VERSION	= 0,
 	BOOTSTAGE_MAGIC		= 0xb00757a3,
 	BOOTSTAGE_DIGITS	= 9,
 };

 struct bootstage_hdr {
 	uint32_t version;	/* BOOTSTAGE_VERSION */
 	uint32_t count;		/* Number of records */
 	uint32_t size;		/* Total data size (non-zero if valid) */
 	uint32_t magic;		/* Unused */
 };

 int bootstage_relocate(void)
 {
 	struct bootstage_data *data = gd->bootstage;
 	int i;

 	/*
 	 * Duplicate all strings.  They may point to an old location in the
 	 * program .text section that can eventually get trashed.
 	 */
 	debug("Relocating %d records\n", data->rec_count);
 	for (i = 0; i < data->rec_count; i++)
 		data->record[i].name = strdup(data->record[i].name);

 	return 0;
 }

 struct bootstage_record *find_id(struct bootstage_data *data,
 				 enum bootstage_id id)
 {
 	struct bootstage_record *rec;
 	struct bootstage_record *end;

 	for (rec = data->record, end = rec + data->rec_count; rec < end;
 	     rec++) {
 		if (rec->id == id)
 			return rec;
 	}

 	return NULL;
 }

 struct bootstage_record *ensure_id(struct bootstage_data *data,
 				   enum bootstage_id id)
 {
 	struct bootstage_record *rec;

 	rec = find_id(data, id);
 	if (!rec && data->rec_count < RECORD_COUNT) {
 		rec = &data->record[data->rec_count++];
 		rec->id = id;
 		return rec;
 	}

 	return rec;
 }

 ulong bootstage_add_record(enum bootstage_id id, const char *name,
 			   int flags, ulong mark)
 {
 	struct bootstage_data *data = gd->bootstage;
 	struct bootstage_record *rec;

 	/*
 	 * initf_bootstage() is called very early during boot but since hang()
 	 * calls bootstage_error() we can be called before bootstage is set up.
 	 * Add a check to avoid this.
 	 */
 	if (!data)
 		return mark;
 	if (flags & BOOTSTAGEF_ALLOC)
 		id = data->next_id++;

 	/* Only record the first event for each */
 	rec = find_id(data, id);
 	if (!rec && data->rec_count < RECORD_COUNT) {
 		rec = &data->record[data->rec_count++];
 		rec->time_us = mark;
 		rec->name = name;
 		rec->flags = flags;
 		rec->id = id;
 	}

 	/* Tell the board about this progress */
 	show_boot_progress(flags & BOOTSTAGEF_ERROR ? -id : id);

 	return mark;
 }


 ulong bootstage_mark(enum bootstage_id id)
 {
 	return bootstage_add_record(id, NULL, 0, timer_get_boot_us());
 }

 ulong bootstage_error(enum bootstage_id id)
 {
 	return bootstage_add_record(id, NULL, BOOTSTAGEF_ERROR,
 				    timer_get_boot_us());
 }

 ulong bootstage_mark_name(enum bootstage_id id, const char *name)
 {
 	int flags = 0;

 	if (id == BOOTSTAGE_ID_ALLOC)
 		flags = BOOTSTAGEF_ALLOC;

 	return bootstage_add_record(id, name, flags, timer_get_boot_us());
 }

 ulong bootstage_mark_code(const char *file, const char *func, int linenum)
 {
 	char *str, *p;
 	__maybe_unused char *end;
 	int len = 0;

 	/* First work out the length we need to allocate */
 	if (linenum != -1)
 		len = 11;
 	if (func)
 		len += strlen(func);
 	if (file)
 		len += strlen(file);

 	str = malloc(len + 1);
 	p = str;
 	end = p + len;
 	if (file)
 		p += snprintf(p, end - p, "%s,", file);
 	if (linenum != -1)
 		p += snprintf(p, end - p, "%d", linenum);
 	if (func)
 		p += snprintf(p, end - p, ": %s", func);

 	return bootstage_mark_name(BOOTSTAGE_ID_ALLOC, str);
 }

 uint32_t bootstage_start(enum bootstage_id id, const char *name)
 {
 	struct bootstage_data *data = gd->bootstage;
 	struct bootstage_record *rec = ensure_id(data, id);
 	ulong start_us = timer_get_boot_us();

 	if (rec) {
 		rec->start_us = start_us;
 		rec->name = name;
 	}

 	return start_us;
 }

 uint32_t bootstage_accum(enum bootstage_id id)
 {
 	struct bootstage_data *data = gd->bootstage;
 	struct bootstage_record *rec = ensure_id(data, id);
 	uint32_t duration;

 	if (!rec)
 		return 0;
 	duration = (uint32_t)timer_get_boot_us() - rec->start_us;
 	rec->time_us += duration;

 	return duration;
 }

 /**
  * Get a record name as a printable string
  *
  * @param buf	Buffer to put name if needed
  * @param len	Length of buffer
  * @param rec	Boot stage record to get the name from
  * @return pointer to name, either from the record or pointing to buf.
  */
 static const char *get_record_name(char *buf, int len,
 				   const struct bootstage_record *rec)
 {
 	if (rec->name)
 		return rec->name;
 	else if (rec->id >= BOOTSTAGE_ID_USER)
 		snprintf(buf, len, "user_%d", rec->id - BOOTSTAGE_ID_USER);
 	else
 		snprintf(buf, len, "id=%d", rec->id);

 	return buf;
 }

 static uint32_t print_time_record(struct bootstage_record *rec, uint32_t prev)
 {
 	char buf[20];

 	if (prev == -1U) {
 		printf("%11s", "");
 		print_grouped_ull(rec->time_us, BOOTSTAGE_DIGITS);
 	} else {
 		print_grouped_ull(rec->time_us, BOOTSTAGE_DIGITS);
 		print_grouped_ull(rec->time_us - prev, BOOTSTAGE_DIGITS);
 	}
 	printf("  %s\n", get_record_name(buf, sizeof(buf), rec));

 	return rec->time_us;
 }

 static int h_compare_record(const void *r1, const void *r2)
 {
 	const struct bootstage_record *rec1 = r1, *rec2 = r2;

 	return rec1->time_us > rec2->time_us ? 1 : -1;
 }

 #ifdef CONFIG_OF_LIBFDT
 /**
  * Add all bootstage timings to a device tree.
  *
  * @param blob	Device tree blob
  * @return 0 on success, != 0 on failure.
  */
 static int add_bootstages_devicetree(struct fdt_header *blob)
 {
 	struct bootstage_data *data = gd->bootstage;
 	int bootstage;
 	char buf[20];
 	int recnum;
 	int i;

 	if (!blob)
 		return 0;

 	/*
 	 * Create the node for bootstage.
 	 * The address of flat device tree is set up by the command bootm.
 	 */
 	bootstage = fdt_add_subnode(blob, 0, "bootstage");
 	if (bootstage < 0)
 		return -EINVAL;

 	/*
 	 * Insert the timings to the device tree in the reverse order so
 	 * that they can be printed in the Linux kernel in the right order.
 	 */
 	for (recnum = data->rec_count - 1, i = 0; recnum >= 0; recnum--, i++) {
 		struct bootstage_record *rec = &data->record[recnum];
 		int node;

 		if (rec->id != BOOTSTAGE_ID_AWAKE && rec->time_us == 0)
 			continue;

 		node = fdt_add_subnode(blob, bootstage, simple_itoa(i));
 		if (node < 0)
 			break;

 		/* add properties to the node. */
 		if (fdt_setprop_string(blob, node, "name",
 				       get_record_name(buf, sizeof(buf), rec)))
 			return -EINVAL;

 		/* Check if this is a 'mark' or 'accum' record */
 		if (fdt_setprop_cell(blob, node,
 				rec->start_us ? "accum" : "mark",
 				rec->time_us))
 			return -EINVAL;
 	}

 	return 0;
 }

 int bootstage_fdt_add_report(void)
 {
 	if (add_bootstages_devicetree(working_fdt))
 		puts("bootstage: Failed to add to device tree\n");

 	return 0;
 }
 #endif

 void bootstage_report(void)
 {
 	struct bootstage_data *data = gd->bootstage;
 	struct bootstage_record *rec = data->record;
 	uint32_t prev;
 	int i;

 	printf("Timer summary in microseconds (%d records):\n",
 	       data->rec_count);
 	printf("%11s%11s  %s\n", "Mark", "Elapsed", "Stage");

 	prev = print_time_record(rec, 0);

 	/* Sort records by increasing time */
 	qsort(data->record, data->rec_count, sizeof(*rec), h_compare_record);

 	for (i = 1, rec++; i < data->rec_count; i++, rec++) {
 		if (rec->id && !rec->start_us)
 			prev = print_time_record(rec, prev);
 	}
 	if (data->rec_count > RECORD_COUNT)
 		printf("Overflowed internal boot id table by %d entries\n"
 		       "Please increase CONFIG_(SPL_)BOOTSTAGE_RECORD_COUNT\n",
 		       data->rec_count - RECORD_COUNT);

 	puts("\nAccumulated time:\n");
 	for (i = 0, rec = data->record; i < data->rec_count; i++, rec++) {
 		if (rec->start_us)
 			prev = print_time_record(rec, -1);
 	}
 }

 /**
  * Append data to a memory buffer
  *
  * Write data to the buffer if there is space. Whether there is space or not,
  * the buffer pointer is incremented.
  *
  * @param ptrp	Pointer to buffer, updated by this function
  * @param end	Pointer to end of buffer
  * @param data	Data to write to buffer
  * @param size	Size of data
  */
 static void append_data(char **ptrp, char *end, const void *data, int size)
 {
 	char *ptr = *ptrp;

 	*ptrp += size;
 	if (*ptrp > end)
 		return;

 	memcpy(ptr, data, size);
 }

 int bootstage_stash(void *base, int size)
 {
 	const struct bootstage_data *data = gd->bootstage;
 	struct bootstage_hdr *hdr = (struct bootstage_hdr *)base;
 	const struct bootstage_record *rec;
 	char buf[20];
 	char *ptr = base, *end = ptr + size;
 	uint32_t count;
 	int i;

 	if (hdr + 1 > (struct bootstage_hdr *)end) {
 		debug("%s: Not enough space for bootstage hdr\n", __func__);
 		return -ENOSPC;
 	}

 	/* Write an arbitrary version number */
 	hdr->version = BOOTSTAGE_VERSION;

 	/* Count the number of records, and write that value first */
 	for (rec = data->record, i = count = 0; i < data->rec_count;
 	     i++, rec++) {
 		if (rec->id != 0)
 			count++;
 	}
 	hdr->count = count;
 	hdr->size = 0;
 	hdr->magic = BOOTSTAGE_MAGIC;
 	ptr += sizeof(*hdr);

 	/* Write the records, silently stopping when we run out of space */
 	for (rec = data->record, i = 0; i < data->rec_count; i++, rec++) {
 		append_data(&ptr, end, rec, sizeof(*rec));
 	}

 	/* Write the name strings */
 	for (rec = data->record, i = 0; i < data->rec_count; i++, rec++) {
 		const char *name;

 		name = get_record_name(buf, sizeof(buf), rec);
 		append_data(&ptr, end, name, strlen(name) + 1);
 	}

 	/* Check for buffer overflow */
 	if (ptr > end) {
 		debug("%s: Not enough space for bootstage stash\n", __func__);
 		return -ENOSPC;
 	}

 	/* Update total data size */
 	hdr->size = ptr - (char *)base;
 	debug("Stashed %d records\n", hdr->count);

 	return 0;
 }

 int bootstage_unstash(const void *base, int size)
 {
 	const struct bootstage_hdr *hdr = (struct bootstage_hdr *)base;
 	struct bootstage_data *data = gd->bootstage;
 	const char *ptr = base, *end = ptr + size;
 	struct bootstage_record *rec;
 	uint rec_size;
 	int i;

 	if (size == -1)
 		end = (char *)(~(uintptr_t)0);

 	if (hdr + 1 > (struct bootstage_hdr *)end) {
 		debug("%s: Not enough space for bootstage hdr\n", __func__);
 		return -EPERM;
 	}

 	if (hdr->magic != BOOTSTAGE_MAGIC) {
 		debug("%s: Invalid bootstage magic\n", __func__);
 		return -ENOENT;
 	}

 	if (ptr + hdr->size > end) {
 		debug("%s: Bootstage data runs past buffer end\n", __func__);
 		return -ENOSPC;
 	}

 	if (hdr->count * sizeof(*rec) > hdr->size) {
 		debug("%s: Bootstage has %d records needing %lu bytes, but "
 			"only %d bytes is available\n", __func__, hdr->count,
 		      (ulong)hdr->count * sizeof(*rec), hdr->size);
 		return -ENOSPC;
 	}

 	if (hdr->version != BOOTSTAGE_VERSION) {
 		debug("%s: Bootstage data version %#0x unrecognised\n",
 		      __func__, hdr->version);
 		return -EINVAL;
 	}

 	if (data->rec_count + hdr->count > RECORD_COUNT) {
 		debug("%s: Bootstage has %d records, we have space for %d\n"
 			"Please increase CONFIG_(SPL_)BOOTSTAGE_RECORD_COUNT\n",
 		      __func__, hdr->count, RECORD_COUNT - data->rec_count);
 		return -ENOSPC;
 	}

 	ptr += sizeof(*hdr);

 	/* Read the records */
 	rec_size = hdr->count * sizeof(*data->record);
 	memcpy(data->record + data->rec_count, ptr, rec_size);

 	/* Read the name strings */
 	ptr += rec_size;
 	for (rec = data->record + data->next_id, i = 0; i < hdr->count;
 	     i++, rec++) {
 		rec->name = ptr;

 		/* Assume no data corruption here */
 		ptr += strlen(ptr) + 1;
 	}

 	/* Mark the records as read */
 	data->rec_count += hdr->count;
 	debug("Unstashed %d records\n", hdr->count);

 	return 0;
 }

 int bootstage_get_size(void)
 {
 	return sizeof(struct bootstage_data);
 }

 int bootstage_init(bool first)
 {
 	struct bootstage_data *data;
 	int size = sizeof(struct bootstage_data);

 	gd->bootstage = (struct bootstage_data *)malloc(size);
 	if (!gd->bootstage)
 		return -ENOMEM;
 	data = gd->bootstage;
 	memset(data, '\0', size);
 	if (first) {
 		data->next_id = BOOTSTAGE_ID_USER;
 		bootstage_add_record(BOOTSTAGE_ID_AWAKE, "reset", 0, 0);
 	}

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (c) 2011, Google Inc. All rights reserved.
	*/


	/*
	* This module records the progress of boot and arbitrary commands, and
	* permits accurate timestamping of each.
	*/

	#include <common.h>
	#include <linux/libfdt.h>
	#include <malloc.h>
	#include <linux/compiler.h>

	DECLARE_GLOBAL_DATA_PTR;

	enum {
	RECORD_COUNT = CONFIG_VAL(BOOTSTAGE_RECORD_COUNT),
	};

	struct bootstage_record {
	ulong time_us;
	uint32_t start_us;
	const char *name;
	int flags; /* see enum bootstage_flags */
	enum bootstage_id id;
	};

	struct bootstage_data {
	uint rec_count;
	uint next_id;
	struct bootstage_record record[RECORD_COUNT];
	};

	enum {
	BOOTSTAGE_VERSION = 0,
	BOOTSTAGE_MAGIC = 0xb00757a3,
	BOOTSTAGE_DIGITS = 9,
	};

	struct bootstage_hdr {
	uint32_t version; /* BOOTSTAGE_VERSION */
	uint32_t count; /* Number of records */
	uint32_t size; /* Total data size (non-zero if valid) */
	uint32_t magic; /* Unused */
	};

	int bootstage_relocate(void)
	{
	struct bootstage_data *data = gd->bootstage;
	int i;

	/*
	* Duplicate all strings. They may point to an old location in the
	* program .text section that can eventually get trashed.
	*/
	debug("Relocating %d records\n", data->rec_count);
	for (i = 0; i < data->rec_count; i++)
	data->record[i].name = strdup(data->record[i].name);

	return 0;
	}

	struct bootstage_record find_id(struct bootstage_data data,
	enum bootstage_id id)
	{
	struct bootstage_record *rec;
	struct bootstage_record *end;

	for (rec = data->record, end = rec + data->rec_count; rec < end;
	rec++) {
	if (rec->id == id)
	return rec;
	}

	return NULL;
	}

	struct bootstage_record ensure_id(struct bootstage_data data,
	enum bootstage_id id)
	{
	struct bootstage_record *rec;

	rec = find_id(data, id);
	if (!rec && data->rec_count < RECORD_COUNT) {
	rec = &data->record[data->rec_count++];
	rec->id = id;
	return rec;
	}

	return rec;
	}

	ulong bootstage_add_record(enum bootstage_id id, const char *name,
	int flags, ulong mark)
	{
	struct bootstage_data *data = gd->bootstage;
	struct bootstage_record *rec;

	/*
	* initf_bootstage() is called very early during boot but since hang()
	* calls bootstage_error() we can be called before bootstage is set up.
	* Add a check to avoid this.
	*/
	if (!data)
	return mark;
	if (flags & BOOTSTAGEF_ALLOC)
	id = data->next_id++;

	/* Only record the first event for each */
	rec = find_id(data, id);
	if (!rec && data->rec_count < RECORD_COUNT) {
	rec = &data->record[data->rec_count++];
	rec->time_us = mark;
	rec->name = name;
	rec->flags = flags;
	rec->id = id;
	}

	/* Tell the board about this progress */
	show_boot_progress(flags & BOOTSTAGEF_ERROR ? -id : id);

	return mark;
	}


	ulong bootstage_mark(enum bootstage_id id)
	{
	return bootstage_add_record(id, NULL, 0, timer_get_boot_us());
	}

	ulong bootstage_error(enum bootstage_id id)
	{
	return bootstage_add_record(id, NULL, BOOTSTAGEF_ERROR,
	timer_get_boot_us());
	}

	ulong bootstage_mark_name(enum bootstage_id id, const char *name)
	{
	int flags = 0;

	if (id == BOOTSTAGE_ID_ALLOC)
	flags = BOOTSTAGEF_ALLOC;

	return bootstage_add_record(id, name, flags, timer_get_boot_us());
	}

	ulong bootstage_mark_code(const char file, const char func, int linenum)
	{
	char str, p;
	__maybe_unused char *end;
	int len = 0;

	/* First work out the length we need to allocate */
	if (linenum != -1)
	len = 11;
	if (func)
	len += strlen(func);
	if (file)
	len += strlen(file);

	str = malloc(len + 1);
	p = str;
	end = p + len;
	if (file)
	p += snprintf(p, end - p, "%s,", file);
	if (linenum != -1)
	p += snprintf(p, end - p, "%d", linenum);
	if (func)
	p += snprintf(p, end - p, ": %s", func);

	return bootstage_mark_name(BOOTSTAGE_ID_ALLOC, str);
	}

	uint32_t bootstage_start(enum bootstage_id id, const char *name)
	{
	struct bootstage_data *data = gd->bootstage;
	struct bootstage_record *rec = ensure_id(data, id);
	ulong start_us = timer_get_boot_us();

	if (rec) {
	rec->start_us = start_us;
	rec->name = name;
	}

	return start_us;
	}

	uint32_t bootstage_accum(enum bootstage_id id)
	{
	struct bootstage_data *data = gd->bootstage;
	struct bootstage_record *rec = ensure_id(data, id);
	uint32_t duration;

	if (!rec)
	return 0;
	duration = (uint32_t)timer_get_boot_us() - rec->start_us;
	rec->time_us += duration;

	return duration;
	}

	/**
	* Get a record name as a printable string
	*
	* @param buf Buffer to put name if needed
	* @param len Length of buffer
	* @param rec Boot stage record to get the name from
	* @return pointer to name, either from the record or pointing to buf.
	*/
	static const char get_record_name(char buf, int len,
	const struct bootstage_record *rec)
	{
	if (rec->name)
	return rec->name;
	else if (rec->id >= BOOTSTAGE_ID_USER)
	snprintf(buf, len, "user_%d", rec->id - BOOTSTAGE_ID_USER);
	else
	snprintf(buf, len, "id=%d", rec->id);

	return buf;
	}

	static uint32_t print_time_record(struct bootstage_record *rec, uint32_t prev)
	{
	char buf[20];

	if (prev == -1U) {
	printf("%11s", "");
	print_grouped_ull(rec->time_us, BOOTSTAGE_DIGITS);
	} else {
	print_grouped_ull(rec->time_us, BOOTSTAGE_DIGITS);
	print_grouped_ull(rec->time_us - prev, BOOTSTAGE_DIGITS);
	}
	printf(" %s\n", get_record_name(buf, sizeof(buf), rec));

	return rec->time_us;
	}

	static int h_compare_record(const void r1, const void r2)
	{
	const struct bootstage_record rec1 = r1, rec2 = r2;

	return rec1->time_us > rec2->time_us ? 1 : -1;
	}

	#ifdef CONFIG_OF_LIBFDT
	/**
	* Add all bootstage timings to a device tree.
	*
	* @param blob Device tree blob
	* @return 0 on success, != 0 on failure.
	*/
	static int add_bootstages_devicetree(struct fdt_header *blob)
	{
	struct bootstage_data *data = gd->bootstage;
	int bootstage;
	char buf[20];
	int recnum;
	int i;

	if (!blob)
	return 0;

	/*
	* Create the node for bootstage.
	* The address of flat device tree is set up by the command bootm.
	*/
	bootstage = fdt_add_subnode(blob, 0, "bootstage");
	if (bootstage < 0)
	return -EINVAL;

	/*
	* Insert the timings to the device tree in the reverse order so
	* that they can be printed in the Linux kernel in the right order.
	*/
	for (recnum = data->rec_count - 1, i = 0; recnum >= 0; recnum--, i++) {
	struct bootstage_record *rec = &data->record[recnum];
	int node;

	if (rec->id != BOOTSTAGE_ID_AWAKE && rec->time_us == 0)
	continue;

	node = fdt_add_subnode(blob, bootstage, simple_itoa(i));
	if (node < 0)
	break;

	/* add properties to the node. */
	if (fdt_setprop_string(blob, node, "name",
	get_record_name(buf, sizeof(buf), rec)))
	return -EINVAL;

	/* Check if this is a 'mark' or 'accum' record */
	if (fdt_setprop_cell(blob, node,
	rec->start_us ? "accum" : "mark",
	rec->time_us))
	return -EINVAL;
	}

	return 0;
	}

	int bootstage_fdt_add_report(void)
	{
	if (add_bootstages_devicetree(working_fdt))
	puts("bootstage: Failed to add to device tree\n");

	return 0;
	}
	#endif

	void bootstage_report(void)
	{
	struct bootstage_data *data = gd->bootstage;
	struct bootstage_record *rec = data->record;
	uint32_t prev;
	int i;

	printf("Timer summary in microseconds (%d records):\n",
	data->rec_count);
	printf("%11s%11s %s\n", "Mark", "Elapsed", "Stage");

	prev = print_time_record(rec, 0);

	/* Sort records by increasing time */
	qsort(data->record, data->rec_count, sizeof(*rec), h_compare_record);

	for (i = 1, rec++; i < data->rec_count; i++, rec++) {
	if (rec->id && !rec->start_us)
	prev = print_time_record(rec, prev);
	}
	if (data->rec_count > RECORD_COUNT)
	printf("Overflowed internal boot id table by %d entries\n"
	"Please increase CONFIG_(SPL_)BOOTSTAGE_RECORD_COUNT\n",
	data->rec_count - RECORD_COUNT);

	puts("\nAccumulated time:\n");
	for (i = 0, rec = data->record; i < data->rec_count; i++, rec++) {
	if (rec->start_us)
	prev = print_time_record(rec, -1);
	}
	}

	/**
	* Append data to a memory buffer
	*
	* Write data to the buffer if there is space. Whether there is space or not,
	* the buffer pointer is incremented.
	*
	* @param ptrp Pointer to buffer, updated by this function
	* @param end Pointer to end of buffer
	* @param data Data to write to buffer
	* @param size Size of data
	*/
	static void append_data(char *ptrp, char end, const void *data, int size)
	{
	char ptr = ptrp;

	*ptrp += size;
	if (*ptrp > end)
	return;

	memcpy(ptr, data, size);
	}

	int bootstage_stash(void *base, int size)
	{
	const struct bootstage_data *data = gd->bootstage;
	struct bootstage_hdr hdr = (struct bootstage_hdr )base;
	const struct bootstage_record *rec;
	char buf[20];
	char ptr = base, end = ptr + size;
	uint32_t count;
	int i;

	if (hdr + 1 > (struct bootstage_hdr *)end) {
	debug("%s: Not enough space for bootstage hdr\n", __func__);
	return -ENOSPC;
	}

	/* Write an arbitrary version number */
	hdr->version = BOOTSTAGE_VERSION;

	/* Count the number of records, and write that value first */
	for (rec = data->record, i = count = 0; i < data->rec_count;
	i++, rec++) {
	if (rec->id != 0)
	count++;
	}
	hdr->count = count;
	hdr->size = 0;
	hdr->magic = BOOTSTAGE_MAGIC;
	ptr += sizeof(*hdr);

	/* Write the records, silently stopping when we run out of space */
	for (rec = data->record, i = 0; i < data->rec_count; i++, rec++) {
	append_data(&ptr, end, rec, sizeof(*rec));
	}

	/* Write the name strings */
	for (rec = data->record, i = 0; i < data->rec_count; i++, rec++) {
	const char *name;

	name = get_record_name(buf, sizeof(buf), rec);
	append_data(&ptr, end, name, strlen(name) + 1);
	}

	/* Check for buffer overflow */
	if (ptr > end) {
	debug("%s: Not enough space for bootstage stash\n", __func__);
	return -ENOSPC;
	}

	/* Update total data size */
	hdr->size = ptr - (char *)base;
	debug("Stashed %d records\n", hdr->count);

	return 0;
	}

	int bootstage_unstash(const void *base, int size)
	{
	const struct bootstage_hdr hdr = (struct bootstage_hdr )base;
	struct bootstage_data *data = gd->bootstage;
	const char ptr = base, end = ptr + size;
	struct bootstage_record *rec;
	uint rec_size;
	int i;

	if (size == -1)
	end = (char *)(~(uintptr_t)0);

	if (hdr + 1 > (struct bootstage_hdr *)end) {
	debug("%s: Not enough space for bootstage hdr\n", __func__);
	return -EPERM;
	}

	if (hdr->magic != BOOTSTAGE_MAGIC) {
	debug("%s: Invalid bootstage magic\n", __func__);
	return -ENOENT;
	}

	if (ptr + hdr->size > end) {
	debug("%s: Bootstage data runs past buffer end\n", __func__);
	return -ENOSPC;
	}

	if (hdr->count * sizeof(*rec) > hdr->size) {
	debug("%s: Bootstage has %d records needing %lu bytes, but "
	"only %d bytes is available\n", __func__, hdr->count,
	(ulong)hdr->count * sizeof(*rec), hdr->size);
	return -ENOSPC;
	}

	if (hdr->version != BOOTSTAGE_VERSION) {
	debug("%s: Bootstage data version %#0x unrecognised\n",
	__func__, hdr->version);
	return -EINVAL;
	}

	if (data->rec_count + hdr->count > RECORD_COUNT) {
	debug("%s: Bootstage has %d records, we have space for %d\n"
	"Please increase CONFIG_(SPL_)BOOTSTAGE_RECORD_COUNT\n",
	__func__, hdr->count, RECORD_COUNT - data->rec_count);
	return -ENOSPC;
	}

	ptr += sizeof(*hdr);

	/* Read the records */
	rec_size = hdr->count * sizeof(*data->record);
	memcpy(data->record + data->rec_count, ptr, rec_size);

	/* Read the name strings */
	ptr += rec_size;
	for (rec = data->record + data->next_id, i = 0; i < hdr->count;
	i++, rec++) {
	rec->name = ptr;

	/* Assume no data corruption here */
	ptr += strlen(ptr) + 1;
	}

	/* Mark the records as read */
	data->rec_count += hdr->count;
	debug("Unstashed %d records\n", hdr->count);

	return 0;
	}

	int bootstage_get_size(void)
	{
	return sizeof(struct bootstage_data);
	}

	int bootstage_init(bool first)
	{
	struct bootstage_data *data;
	int size = sizeof(struct bootstage_data);

	gd->bootstage = (struct bootstage_data *)malloc(size);
	if (!gd->bootstage)
	return -ENOMEM;
	data = gd->bootstage;
	memset(data, '\0', size);
	if (first) {
	data->next_id = BOOTSTAGE_ID_USER;
	bootstage_add_record(BOOTSTAGE_ID_AWAKE, "reset", 0, 0);
	}

	return 0;
	}