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u-boot/arch/powerpc/include/asm/global_data.h
Wolfgang Denk ea882baf9c New implementation for internal handling of environment variables. 
Motivation:

* Old environment code used a pessimizing implementation:
  - variable lookup used linear search => slow
  - changed/added variables were added at the end, i. e. most
    frequently used variables had the slowest access times => slow
  - each setenv() would calculate the CRC32 checksum over the whole
    environment block => slow
* "redundant" envrionment was locked down to two copies
* No easy way to implement features like "reset to factory defaults",
  or to select one out of several pre-defined (previously saved) sets
  of environment settings ("profiles")
* No easy way to import or export environment settings

======================================================================

API Changes:

- Variable names starting with '#' are no longer allowed

  I didn't find any such variable names being used; it is highly
  recommended to follow standard conventions and start variable names
  with an alphanumeric character

- "printenv" will now print a backslash at the end of all but the last
  lines of a multi-line variable value.

  Multi-line variables have never been formally defined, allthough
  there is no reason not to use them. Now we define rules how to deal
  with them, allowing for import and export.

- Function forceenv() and the related code in saveenv() was removed.
  At the moment this is causing build problems for the only user of
  this code (schmoogie - which has no entry in MAINTAINERS); may be
  fixed later by implementing the "env set -f" feature.

Inconsistencies:

- "printenv" will '\\'-escape the '\n' in multi-line variables, while
  "printenv var" will not do that.

======================================================================

Advantages:

- "printenv" output much better readable (sorted)
- faster!
- extendable (additional variable properties can be added)
- new, powerful features like "factory reset" or easy switching
  between several different environment settings ("profiles")

Disadvantages:

- Image size grows by typically 5...7 KiB (might shrink a bit again on
  systems with redundant environment with a following patch series)

======================================================================

Implemented:

- env command with subcommands:

  - env print [arg ...]

    same as "printenv": print environment

  - env set [-f] name [arg ...]

    same as "setenv": set (and delete) environment variables

    ["-f" - force setting even for read-only variables - not
    implemented yet.]

  - end delete [-f] name

    not implemented yet

    ["-f" - force delete even for read-only variables]

  - env save

    same as "saveenv": save environment

  - env export [-t | -b | -c] addr [size]

    export internal representation (hash table) in formats usable for
    persistent storage or processing:

	-t:	export as text format; if size is given, data will be
		padded with '\0' bytes; if not, one terminating '\0'
		will be added (which is included in the "filesize"
		setting so you can for exmple copy this to flash and
		keep the termination).
	-b:	export as binary format (name=value pairs separated by
		'\0', list end marked by double "\0\0")
	-c:	export as checksum protected environment format as
		used for example by "saveenv" command
	addr:	memory address where environment gets stored
	size:	size of output buffer

	With "-c" and size is NOT given, then the export command will
	format the data as currently used for the persistent storage,
	i. e. it will use CONFIG_ENV_SECT_SIZE as output block size and
	prepend a valid CRC32 checksum and, in case of resundant
	environment, a "current" redundancy flag. If size is given, this
	value will be used instead of CONFIG_ENV_SECT_SIZE; again, CRC32
	checksum and redundancy flag will be inserted.

	With "-b" and "-t", always only the real data (including a
	terminating '\0' byte) will be written; here the optional size
	argument will be used to make sure not to overflow the user
	provided buffer; the command will abort if the size is not
	sufficient. Any remainign space will be '\0' padded.

        On successful return, the variable "filesize" will be set.
        Note that filesize includes the trailing/terminating '\0'
        byte(s).

        Usage szenario: create a text snapshot/backup of the current
	settings:

		=> env export -t 100000
		=> era ${backup_addr} +${filesize}
		=> cp.b 100000 ${backup_addr} ${filesize}

	Re-import this snapshot, deleting all other settings:

		=> env import -d -t ${backup_addr}

  - env import [-d] [-t | -b | -c] addr [size]

    import external format (text or binary) into hash table,
    optionally deleting existing values:

	-d:	delete existing environment before importing;
		otherwise overwrite / append to existion definitions
	-t:	assume text format; either "size" must be given or the
		text data must be '\0' terminated
	-b:	assume binary format ('\0' separated, "\0\0" terminated)
	-c:	assume checksum protected environment format
	addr:	memory address to read from
	size:	length of input data; if missing, proper '\0'
		termination is mandatory

  - env default -f

    reset default environment: drop all environment settings and load
    default environment

  - env ask name [message] [size]

    same as "askenv": ask for environment variable

  - env edit name

    same as "editenv": edit environment variable

  - env run

    same as "run": run commands in an environment variable

======================================================================

TODO:

- drop default env as implemented now; provide a text file based
  initialization instead (eventually using several text files to
  incrementally build it from common blocks) and a tool to convert it
  into a binary blob / object file.

- It would be nice if we could add wildcard support for environment
  variables; this is needed for variable name auto-completion,
  but it would also be nice to be able to say "printenv ip*" or
  "printenv *addr*"

- Some boards don't link any more due to the grown code size:
  DU405, canyonlands, sequoia, socrates.

	=> cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
	       Stefan Roese <sr@denx.de>,
	       Heiko Schocher <hs@denx.de>

- Dropping forceenv() causes build problems on schmoogie

	=> cc: Sergey Kubushyn <ksi@koi8.net>

- Build tested on PPC and ARM only; runtime tested with NOR and NAND
  flash only => needs testing!!

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
Cc: Stefan Roese <sr@denx.de>,
Cc: Heiko Schocher <hs@denx.de>
Cc: Sergey Kubushyn <ksi@koi8.net>
2010-09-19 19:29:48 +02:00

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/*
* (C) Copyright 2002-2010
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef __ASM_GBL_DATA_H
#define __ASM_GBL_DATA_H
#include "config.h"
#include "asm/types.h"
/*
* The following data structure is placed in some memory wich is
* available very early after boot (like DPRAM on MPC8xx/MPC82xx, or
* some locked parts of the data cache) to allow for a minimum set of
* global variables during system initialization (until we have set
* up the memory controller so that we can use RAM).
*
* Keep it *SMALL* and remember to set CONFIG_SYS_GBL_DATA_SIZE > sizeof(gd_t)
*/
typedef struct global_data {
bd_t *bd;
unsigned long flags;
unsigned long baudrate;
unsigned long cpu_clk; /* CPU clock in Hz! */
unsigned long bus_clk;
#if defined(CONFIG_8xx)
unsigned long brg_clk;
#endif
#if defined(CONFIG_CPM2)
/* There are many clocks on the MPC8260 - see page 9-5 */
unsigned long vco_out;
unsigned long cpm_clk;
unsigned long scc_clk;
unsigned long brg_clk;
#ifdef CONFIG_PCI
unsigned long pci_clk;
#endif
#endif
unsigned long mem_clk;
#if defined(CONFIG_MPC83xx)
/* There are other clocks in the MPC83XX */
u32 csb_clk;
#if defined(CONFIG_MPC8308) || defined(CONFIG_MPC831x) || \
defined(CONFIG_MPC834x) || defined(CONFIG_MPC837x)
u32 tsec1_clk;
u32 tsec2_clk;
u32 usbdr_clk;
#endif
#if defined (CONFIG_MPC834x)
u32 usbmph_clk;
#endif /* CONFIG_MPC834x */
#if defined(CONFIG_MPC8315)
u32 tdm_clk;
#endif
u32 core_clk;
u32 enc_clk;
u32 lbiu_clk;
u32 lclk_clk;
u32 pci_clk;
#if defined(CONFIG_MPC8308) || defined(CONFIG_MPC831x) || \
defined(CONFIG_MPC837x)
u32 pciexp1_clk;
u32 pciexp2_clk;
#endif
#if defined(CONFIG_MPC837x) || defined(CONFIG_MPC8315)
u32 sata_clk;
#endif
#if defined(CONFIG_MPC8360)
u32 mem_sec_clk;
#endif /* CONFIG_MPC8360 */
#endif
#if defined(CONFIG_FSL_ESDHC)
u32 sdhc_clk;
#endif
#if defined(CONFIG_MPC85xx) || defined(CONFIG_MPC86xx)
u32 lbc_clk;
void *cpu;
#endif /* CONFIG_MPC85xx || CONFIG_MPC86xx */
#if defined(CONFIG_MPC83xx) || defined(CONFIG_MPC85xx) || defined(CONFIG_MPC86xx)
u32 i2c1_clk;
u32 i2c2_clk;
#endif
#if defined(CONFIG_QE)
u32 qe_clk;
u32 brg_clk;
uint mp_alloc_base;
uint mp_alloc_top;
#endif /* CONFIG_QE */
#if defined(CONFIG_FSL_LAW)
u32 used_laws;
#endif
#if defined(CONFIG_E500)
u32 used_tlb_cams[(CONFIG_SYS_NUM_TLBCAMS+31)/32];
#endif
#if defined(CONFIG_MPC5xxx)
unsigned long ipb_clk;
unsigned long pci_clk;
#endif
#if defined(CONFIG_MPC512X)
u32 ips_clk;
u32 csb_clk;
u32 pci_clk;
#endif /* CONFIG_MPC512X */
#if defined(CONFIG_MPC8220)
unsigned long bExtUart;
unsigned long inp_clk;
unsigned long pci_clk;
unsigned long vco_clk;
unsigned long pev_clk;
unsigned long flb_clk;
#endif
phys_size_t ram_size; /* RAM size */
unsigned long reset_status; /* reset status register at boot */
#if defined(CONFIG_MPC83xx)
unsigned long arbiter_event_attributes;
unsigned long arbiter_event_address;
#endif
unsigned long env_addr; /* Address of Environment struct */
unsigned long env_valid; /* Checksum of Environment valid? */
unsigned long have_console; /* serial_init() was called */
#if defined(CONFIG_SYS_ALLOC_DPRAM) || defined(CONFIG_CPM2)
unsigned int dp_alloc_base;
unsigned int dp_alloc_top;
#endif
#if defined(CONFIG_4xx)
u32 uart_clk;
#endif /* CONFIG_4xx */
#if defined(CONFIG_SYS_GT_6426x)
unsigned int mirror_hack[16];
#endif
#if defined(CONFIG_A3000) || \
defined(CONFIG_HIDDEN_DRAGON) || \
defined(CONFIG_MUSENKI) || \
defined(CONFIG_SANDPOINT)
void * console_addr;
#endif
unsigned long relocaddr; /* Start address of U-Boot in RAM */
#if defined(CONFIG_LCD) || defined(CONFIG_VIDEO)
unsigned long fb_base; /* Base address of framebuffer memory */
#endif
#if defined(CONFIG_POST) || defined(CONFIG_LOGBUFFER)
unsigned long post_log_word; /* Record POST activities */
unsigned long post_init_f_time; /* When post_init_f started */
#endif
#ifdef CONFIG_BOARD_TYPES
unsigned long board_type;
#endif
#ifdef CONFIG_MODEM_SUPPORT
unsigned long do_mdm_init;
unsigned long be_quiet;
#endif
#if defined(CONFIG_LWMON) || defined(CONFIG_LWMON5)
unsigned long kbd_status;
#endif
#if defined(CONFIG_WD_MAX_RATE)
unsigned long long wdt_last; /* trace watch-dog triggering rate */
#endif
void **jt; /* jump table */
char env_buf[32]; /* buffer for getenv() before reloc. */
} gd_t;
/*
* Global Data Flags
*/
#define GD_FLG_RELOC 0x00001 /* Code was relocated to RAM */
#define GD_FLG_DEVINIT 0x00002 /* Devices have been initialized */
#define GD_FLG_SILENT 0x00004 /* Silent mode */
#define GD_FLG_POSTFAIL 0x00008 /* Critical POST test failed */
#define GD_FLG_POSTSTOP 0x00010 /* POST seqeunce aborted */
#define GD_FLG_LOGINIT 0x00020 /* Log Buffer has been initialized */
#define GD_FLG_DISABLE_CONSOLE 0x00040 /* Disable console (in & out) */
#define GD_FLG_ENV_READY 0x00080 /* Environment imported into hash table */
#if 1
#define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2")
#else /* We could use plain global data, but the resulting code is bigger */
#define XTRN_DECLARE_GLOBAL_DATA_PTR extern
#define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \
gd_t *gd
#endif
#endif /* __ASM_GBL_DATA_H */
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