111 lines
3.6 KiB
C
111 lines
3.6 KiB
C
/*
|
|
* Copyright (C) 2008 The Android Open Source Project
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef _INCLUDE_SYS__SYSTEM_PROPERTIES_H
|
|
#define _INCLUDE_SYS__SYSTEM_PROPERTIES_H
|
|
|
|
#ifndef _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
|
|
#error you should #include <sys/system_properties.h> instead
|
|
#else
|
|
#include <sys/system_properties.h>
|
|
|
|
typedef struct prop_area prop_area;
|
|
typedef struct prop_msg prop_msg;
|
|
|
|
#define PROP_AREA_MAGIC 0x504f5250
|
|
#define PROP_AREA_VERSION 0x45434f76
|
|
|
|
#define PROP_SERVICE_NAME "property_service"
|
|
#define PROP_FILENAME "/dev/__properties__"
|
|
|
|
/* #define PROP_MAX_ENTRIES 247 */
|
|
/* 247 -> 32620 bytes (<32768) */
|
|
|
|
#define TOC_NAME_LEN(toc) ((toc) >> 24)
|
|
#define TOC_TO_INFO(area, toc) ((prop_info*) (((char*) area) + ((toc) & 0xFFFFFF)))
|
|
|
|
struct prop_area {
|
|
unsigned volatile count;
|
|
unsigned volatile serial;
|
|
unsigned magic;
|
|
unsigned version;
|
|
unsigned reserved[4];
|
|
unsigned toc[1];
|
|
};
|
|
|
|
#define SERIAL_VALUE_LEN(serial) ((serial) >> 24)
|
|
#define SERIAL_DIRTY(serial) ((serial) & 1)
|
|
|
|
struct prop_info {
|
|
char name[PROP_NAME_MAX];
|
|
unsigned volatile serial;
|
|
char value[PROP_VALUE_MAX];
|
|
};
|
|
|
|
struct prop_msg
|
|
{
|
|
unsigned cmd;
|
|
char name[PROP_NAME_MAX];
|
|
char value[PROP_VALUE_MAX];
|
|
};
|
|
|
|
#define PROP_MSG_SETPROP 1
|
|
|
|
/*
|
|
** Rules:
|
|
**
|
|
** - there is only one writer, but many readers
|
|
** - prop_area.count will never decrease in value
|
|
** - once allocated, a prop_info's name will not change
|
|
** - once allocated, a prop_info's offset will not change
|
|
** - reading a value requires the following steps
|
|
** 1. serial = pi->serial
|
|
** 2. if SERIAL_DIRTY(serial), wait*, then goto 1
|
|
** 3. memcpy(local, pi->value, SERIAL_VALUE_LEN(serial) + 1)
|
|
** 4. if pi->serial != serial, goto 2
|
|
**
|
|
** - writing a value requires the following steps
|
|
** 1. pi->serial = pi->serial | 1
|
|
** 2. memcpy(pi->value, local_value, value_len)
|
|
** 3. pi->serial = (value_len << 24) | ((pi->serial + 1) & 0xffffff)
|
|
**
|
|
** Improvements:
|
|
** - maintain the toc sorted by pi->name to allow lookup
|
|
** by binary search
|
|
**
|
|
*/
|
|
|
|
#define PROP_PATH_RAMDISK_DEFAULT "/default.prop"
|
|
#define PROP_PATH_SYSTEM_BUILD "/system/build.prop"
|
|
#define PROP_PATH_SYSTEM_DEFAULT "/system/default.prop"
|
|
#define PROP_PATH_LOCAL_OVERRIDE "/data/local.prop"
|
|
#define PROP_PATH_FACTORY "/factory/factory.prop"
|
|
|
|
#endif
|
|
#endif
|