From 1209e2727c60d052ce875aa39bb8b9ba2edbfbdf Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Sun, 10 Nov 2013 10:27:04 -0700 Subject: sandbox: Add facility to save/restore sandbox state It is often useful to be able to save out the state from a sandbox test run, for analysis or to restore it later to continue a test. Add generic infrastructure for doing this using a device tree binary file. This is a flexible tagged file format which is already supported by U-Boot, and it supports hierarchy if needed. Signed-off-by: Simon Glass Signed-off-by: Simon Glass Reviewed-by: Hung-ying Tyan --- arch/sandbox/include/asm/state.h | 114 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) (limited to 'arch/sandbox/include/asm/state.h') diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h index e4b4c72463..e8e4fea1b5 100644 --- a/arch/sandbox/include/asm/state.h +++ b/arch/sandbox/include/asm/state.h @@ -8,6 +8,7 @@ #include #include +#include /* How we exited U-Boot */ enum exit_type_id { @@ -34,12 +35,82 @@ struct sandbox_state { 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. * @@ -54,6 +125,49 @@ void state_record_exit(enum exit_type_id exit_type); */ 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 */ -- cgit v1.2.1