iBoot/drivers/flash_nand/boot/nvram/nand_nvram_impl.h

296 lines
7.5 KiB
C

/*
* Copyright (c) 2008-2012 Apple Inc. All rights reserved.
*
* This document is the property of Apple Inc.
* It is considered confidential and proprietary.
*
* This document may not be reproduced or transmitted in any form,
* in whole or in part, without the express written permission of
* Apple Inc.
*/
/* ========================================================================== */
/*!
@header nand_nvram_impl
@abstract portable header info for nand nvram implementation use only
@discussion These declarations have been pulled out into an
independent file so that diagnostic utilities and white box unit
tests might take advantage of knowing implementation-specific
details. Nevertheless, no client of the nand nvram driver nor its
system-specific wrapper should ever need to reference this header.
Any declarations that need that level of visibility are intended to
be placed in "nand_nvram_core.h".
@copyright Apple Inc.
@updated 2012-02-21
*/
/* ========================================================================== */
#ifndef _NAND_NVRAM_IMPL_H
#define _NAND_NVRAM_IMPL_H
__BEGIN_DECLS
/* ========================================================================== */
/*!
@group public platform-independent type declarations
*/
/*!
@typedef nand_nvram_t
@abstract Opaque reference to structure needed by nand nvram implementation.
*/
typedef struct nand_nvram nand_nvram_t;
/*!
@typedef nand_nvram_geometry_t
@abstract
*/
typedef struct nand_nvram_geometry nand_nvram_geometry_t;
/* ========================================================================== */
/*!
@group private platform-independent type declarations
*/
typedef struct _meta meta_t;
typedef struct _blob blob_t;
/* ========================================================================== */
/*!
@group public platform-independent constant definitions
*/
/*!
@const kNAND_NVRAM_SIZE
@abstract Standard size of nvram presented by the driver. Note
that, if this ends up changing in the future, this value should
start being defined on a platform/product specific basis.
*/
#define kNAND_NVRAM_SIZE 8192
/*!
@const kNAND_NVRAM_META_SIZE
@abstract Amount of bytes required by meta data for each nvram
backing store page.
*/
#define kNAND_NVRAM_META_SIZE 10
/*!
@const kNAND_NVRAM_PAGE_RESERVED_IN_BLOCK
@abstract Number of pages reserved for partition table in each
NAND block.
*/
#define kNAND_NVRAM_PAGE_RESERVED_IN_BLOCK 2
/* ========================================================================== */
/*!
@group private platform-independent constant definitions
*/
/*!
@const NULL
@abstract It really sucks that some of our systems don't define NULL.
*/
#ifndef NULL
#define NULL ((void *)0)
#endif
/*!
@const kNAND_NVRAM_MAX_SIZE
@abstract Maximum amount of storage; should fit into a standard 2K page.
*/
#define kNAND_NVRAM_MAX_SIZE (128 * 2048)
/*!
@const kNAND_NVRAM_SIGNATURE
@abstract Constant value used to identify nand nvram meta data.
*/
#define kNAND_NVRAM_SIGNATURE ((uint16_t) 0xBEAD)
/*!
@const kNAND_NVRAM_VERSION_MAJOR
@abstract Major version of the driver that wrote the nvram content.
Major version differences are considered to be incompatible. Even
major version numbers are reserved for development purposes; odd
version numbers should be used for when development is frozen,
stabilized, and therefore only accepting minor revision level changes.
*/
#define kNAND_NVRAM_FEATURE_EXTRA_AREA_VERSION_MAJOR ((uint8_t) 0x0)
#define kNAND_NVRAM_VERSION_MAJOR kNAND_NVRAM_FEATURE_EXTRA_AREA_VERSION_MAJOR
/*!
@const kNAND_NVRAM_VERSION_MINOR
@abstract Minor version of the driver that wrote the nvram content.
Minor versions should be fully compatible within a major version and
are intended to be incremented when the driver has changed between
public releases.
*/
#define kNAND_NVRAM_FEATURE_EXTRA_AREA_VERSION_MINOR ((uint8_t) 0x3)
#define kNAND_NVRAM_VERSION_MINOR kNAND_NVRAM_FEATURE_EXTRA_AREA_VERSION_MINOR
/*!
@const kNAND_NVRAM_GENERATION_ERASED
@abstract A generation number of all ones is reserved since it also
corresponds to the erased state of nand bits.
*/
#define kNAND_NVRAM_GENERATION_ERASED ((uint32_t) 0xFFFFFFFF)
/*!
@const kNAND_NVRAM_GENERATION_UNKNOWN
@abstract A generation number of all zeros is reserved since it
corresponds to the state of an uninitialized meta struct.
*/
#define kNAND_NVRAM_GENERATION_UNKNOWN ((uint32_t) 0x00000000)
/* ========================================================================== */
/*!
@group public platform-independent structure declarations
*/
/*!
@struct nand_nvram_geometry
@abstract Geometry of nand device array slice.
@field number_of_banks Number of logical banks.
@field blocks_per_bank Number of blocks in each bank.
@field pages_per_block Number of pages per block.
@field data_pages_per_block Number of pages per block available for data storage.
@field bytes_per_page Size in bytes of page.
@field bytes_per_meta_buffer Size in bytes of buffer for in-memory per-page meta info.
@field bytes_per_meta_actual Size in bytes of in-storage per-page meta info (i.e. actual size).
*/
struct nand_nvram_geometry {
uint32_t number_of_banks;
uint32_t blocks_per_bank;
uint32_t pages_per_block;
uint32_t data_pages_per_block;
uint32_t bytes_per_page;
uint32_t bytes_per_meta_buffer;
uint32_t bytes_per_meta_actual;
};
/* ========================================================================== */
/*!
@group private platform-independent structure declarations
*/
/*!
@struct _meta
@abstract Structure defining per-page meta layout.
@field generation Monotonically increasing generation of blob;
kNAND_NVRAM_GENERATION_UNKNOWN and kNAND_NVRAM_GENERATION_ERASED are
reserved values that should never appear on a nand device.
@field page_max Maximum page index for blob (i.e. page count - 1).
@field page_idx Page index of this meta within blob.
@field version_major Major version number of nand nvram driver.
@field version_minor Minor version number of nand nvram driver.
@field signature Constant value of kNAND_NVRAM_SIGNATURE marks valid
nvram meta.
*/
struct _meta {
uint32_t generation;
uint8_t page_max;
uint8_t page_idx;
uint8_t version_major;
uint8_t version_minor;
uint16_t signature;
} __attribute__((__packed__));
/*!
@struct _blob
@abstract Container for N pages of data and meta information
for convenience of writing to/from nand devices.
@field pageCount Number of pages currently allocated to
shadow the blob.
@field metaBufs Buffer containing pages' meta structs.
@field dataBufs Buffer containing pages' data.
*/
struct _blob {
void * meta_bufs;
void * data_bufs;
};
/*!
@struct nand_nvram
@abstract NAND-based nvram driver context information.
@field geometry Geometry of nand device array slice used for
backing store.
@field is_dirty Flag indicating whether shadow has been
modified since last restore or sync.
@field shadow Blob used as container for pages of data and meta
information being shadowed from nand.
@field cursors Array of page numbers of next page in each
bank available for commit.
*/
struct nand_nvram {
nand_nvram_geometry_t geo;
void * context;
uint32_t size;
bool is_born;
bool is_dirty;
uint32_t * watermarks;
uint32_t * cursors;
bool * copies;
blob_t * shadow;
};
/* ========================================================================== */
__END_DECLS
#endif /* ! _NAND_NVRAM_IMPL_H */
/* ========================================================================== */