u-boot/arch/sandbox/include/asm/state.h

/*
 * Copyright (c) 2011-2012 The Chromium OS Authors.
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef __SANDBOX_STATE_H
#define __SANDBOX_STATE_H

#include <config.h>
#include <stdbool.h>
#include <linux/stringify.h>

/* How we exited U-Boot */
enum exit_type_id {
	STATE_EXIT_NORMAL,
	STATE_EXIT_COLD_REBOOT,
	STATE_EXIT_POWER_OFF,
};

struct sandbox_spi_info {
	const char *spec;
	const struct sandbox_spi_emu_ops *ops;
};

/* The complete state of the test system */
struct sandbox_state {
	const char *cmd;		/* Command to execute */
	bool interactive;		/* Enable cmdline after execute */
	const char *fdt_fname;		/* Filename of FDT binary */
	enum exit_type_id exit_type;	/* How we exited U-Boot */
	const char *parse_err;		/* Error to report from parsing */
	int argc;			/* Program arguments */
	char **argv;
	uint8_t *ram_buf;		/* Emulated RAM buffer */
	unsigned int ram_size;		/* Size of RAM buffer */
	const char *ram_buf_fname;	/* Filename to use for RAM buffer */
	bool write_ram_buf;		/* Write RAM buffer on exit */
	const char *state_fname;	/* File containing sandbox state */
	void *state_fdt;		/* Holds saved state for sandbox */
	bool read_state;		/* Read sandbox state on startup */
	bool write_state;		/* Write sandbox state on exit */
	bool ignore_missing_state_on_read;	/* No error if state missing */

	/* Pointer to information for each SPI bus/cs */
	struct sandbox_spi_info spi[CONFIG_SANDBOX_SPI_MAX_BUS]
					[CONFIG_SANDBOX_SPI_MAX_CS];
};

/* Minimum space we guarantee in the state FDT when calling read/write*/
#define SANDBOX_STATE_MIN_SPACE		0x1000

/**
 * struct sandbox_state_io - methods to saved/restore sandbox state
 * @name: Name of of the device tree node, also the name of the variable
 *	holding this data so it should be an identifier (use underscore
 *	instead of minus)
 * @compat: Compatible string for the node containing this state
 *
 * @read: Function to read state from FDT
 *	If data is available, then blob and node will provide access to it. If
 *	not (blob == NULL and node == -1) this function should set up an empty
 *	data set for start-of-day.
 *	@param blob: Pointer to device tree blob, or NULL if no data to read
 *	@param node: Node offset to read from
 *	@return 0 if OK, -ve on error
 *
 * @write: Function to write state to FDT
 *	The caller will ensure that there is a node ready for the state. The
 *	node may already contain the old state, in which case it should be
 *	overridden. There is guaranteed to be SANDBOX_STATE_MIN_SPACE bytes
 *	of free space, so error checking is not required for fdt_setprop...()
 *	calls which add up to less than this much space.
 *
 *	For adding larger properties, use state_setprop().
 *
 * @param blob: Device tree blob holding state
 * @param node: Node to write our state into
 *
 * Note that it is possible to save data as large blobs or as individual
 * hierarchical properties. However, unless you intend to keep state files
 * around for a long time and be able to run an old state file on a new
 * sandbox, it might not be worth using individual properties for everything.
 * This is certainly supported, it is just a matter of the effort you wish
 * to put into the state read/write feature.
 */
struct sandbox_state_io {
	const char *name;
	const char *compat;
	int (*write)(void *blob, int node);
	int (*read)(const void *blob, int node);
};

/**
 * SANDBOX_STATE_IO - Declare sandbox state to read/write
 *
 * Sandbox permits saving state from one run and restoring it in another. This
 * allows the test system to retain state between runs and thus better
 * emulate a real system. Examples of state that might be useful to save are
 * the emulated GPIOs pin settings, flash memory contents and TPM private
 * data. U-Boot memory contents is dealth with separately since it is large
 * and it is not normally useful to save it (since a normal system does not
 * preserve DRAM between runs). See the '-m' option for this.
 *
 * See struct sandbox_state_io above for member documentation.
 */
#define SANDBOX_STATE_IO(_name, _compat, _read, _write) \
	ll_entry_declare(struct sandbox_state_io, _name, state_io) = { \
		.name = __stringify(_name), \
		.read = _read, \
		.write = _write, \
		.compat = _compat, \
	}

/**
 * Record the exit type to be reported by the test program.
 *
 * @param exit_type	Exit type to record
 */
void state_record_exit(enum exit_type_id exit_type);

/**
 * Gets a pointer to the current state.
 *
 * @return pointer to state
 */
struct sandbox_state *state_get_current(void);

/**
 * Read the sandbox state from the supplied device tree file
 *
 * This calls all registered state handlers to read in the sandbox state
 * from a previous test run.
 *
 * @param state		Sandbox state to update
 * @param fname		Filename of device tree file to read from
 * @return 0 if OK, -ve on error
 */
int sandbox_read_state(struct sandbox_state *state, const char *fname);

/**
 * Write the sandbox state to the supplied device tree file
 *
 * This calls all registered state handlers to write out the sandbox state
 * so that it can be preserved for a future test run.
 *
 * If the file exists it is overwritten.
 *
 * @param state		Sandbox state to update
 * @param fname		Filename of device tree file to write to
 * @return 0 if OK, -ve on error
 */
int sandbox_write_state(struct sandbox_state *state, const char *fname);

/**
 * Add a property to a sandbox state node
 *
 * This is equivalent to fdt_setprop except that it automatically enlarges
 * the device tree if necessary. That means it is safe to write any amount
 * of data here.
 *
 * This function can only be called from within struct sandbox_state_io's
 * ->write method, i.e. within state I/O drivers.
 *
 * @param node		Device tree node to write to
 * @param prop_name	Property to write
 * @param data		Data to write into property
 * @param size		Size of data to write into property
 */
int state_setprop(int node, const char *prop_name, const void *data, int size);

/**
 * Initialize the test system state
 */
int state_init(void);

/**
 * Uninitialize the test system state, writing out state if configured to
 * do so.
 *
 * @return 0 if OK, -ve on error
 */
int state_uninit(void);

#endif