xref: /rk3399_rockchip-uboot/tools/env/README (revision 6de66b35426312a21174a9bf0576a094e2904bea)
16aff3115Swdenk
26aff3115SwdenkThis is a demo implementation of a Linux command line tool to access
36aff3115Swdenkthe U-Boot's environment variables.
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5d0fb80c3SwdenkFor the run-time utiltity configuration uncomment the line
6d0fb80c3Swdenk#define CONFIG_FILE  "/etc/fw_env.config"
7d0fb80c3Swdenkin fw_env.h.
8d0fb80c3Swdenk
9*6de66b35SMarkus KlotzbücherFor building against older versions of the MTD headers (meaning before
10*6de66b35SMarkus Klotzbücherv2.6.8-rc1) it is required to pass the argument "MTD_VERSION=old" to
11*6de66b35SMarkus Klotzbüchermake.
12*6de66b35SMarkus Klotzbücher
13d0fb80c3SwdenkSee comments in the fw_env.config file for definitions for the
14d0fb80c3Swdenkparticular board.
15d0fb80c3Swdenk
16d0fb80c3SwdenkConfiguration can also be done via #defines in the fw_env.h file. The
176aff3115Swdenkfollowing lines are relevant:
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196aff3115Swdenk#define HAVE_REDUND	/* For systems with 2 env sectors */
206aff3115Swdenk#define DEVICE1_NAME	"/dev/mtd1"
216aff3115Swdenk#define DEVICE2_NAME	"/dev/mtd2"
22d0fb80c3Swdenk#define DEVICE1_OFFSET    0x0000
236aff3115Swdenk#define ENV1_SIZE         0x4000
246aff3115Swdenk#define DEVICE1_ESIZE     0x4000
25d0fb80c3Swdenk#define DEVICE2_OFFSET    0x0000
266aff3115Swdenk#define ENV2_SIZE         0x4000
276aff3115Swdenk#define DEVICE2_ESIZE     0x4000
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296aff3115SwdenkCurrent configuration matches the environment layout of the TRAB
306aff3115Swdenkboard.
316aff3115Swdenk
326aff3115SwdenkUn-define HAVE_REDUND, if you want to use the utlities on a system
33d0fb80c3Swdenkthat does not have support for redundant environment enabled.
34d0fb80c3SwdenkIf HAVE_REDUND is undefined, DEVICE2_NAME is ignored,
35d0fb80c3Swdenkas is ENV2_SIZE and DEVICE2_ESIZE.
36d0fb80c3Swdenk
37d0fb80c3SwdenkThe DEVICEx_NAME constants define which MTD character devices are to
38d0fb80c3Swdenkbe used to access the environment.
39d0fb80c3Swdenk
40d0fb80c3SwdenkThe DEVICEx_OFFSET constants define the environment offset within the
41d0fb80c3SwdenkMTD character device.
42d0fb80c3Swdenk
43d0fb80c3SwdenkENVx_SIZE defines the size in bytes taken by the environment, which
44d0fb80c3Swdenkmay be less then flash sector size, if the environment takes less
45d0fb80c3Swdenkthen 1 sector.
46d0fb80c3Swdenk
476aff3115SwdenkDEVICEx_ESIZE defines the size of the first sector in the flash
48d0fb80c3Swdenkpartition where the environment resides.
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