regdump is a simple program, which dumps registers bit meanings.
It growed while porting U-Boot and Linux to a lot of boards,
and it is not best c code ... maybe it is worth to recode it,
or better use another language then C ... but the benefit
from C is, that regdump can be compiled on the target which
running linux, and regdump can read the register values
through /dev/mem ... not all embedded targets have for
example a phyton compiler ... which I nowadys would prefer
for recoding regdump ...

Regdump needs 2 files:

- registerdescription file:

contains the register descriptions for the cpu/soc

structure:

SOC_Name
{
	register_name register_address register_bit_size
	{
		BIT_name	BIT_start	BIT_stop	defaultvalue
	}
}

comment are marked with a previous '#' and allowed at a start of line, or at
end of a line.

Example:

AM1808
{
	CE3CFG	0x68000014	32
	CE4CFG	0x68000018	32
	CE5CFG	0x6800001c	32
	CE2CFG	0x68000010	32
	{
		SS		31	31	0
		EW		30	30	0
		W_SETUP		29	26	f
		W_STROBE	25	20	3f
		W_HOLD		19	17	7
		R_SETUP		16	13	f
		R_STROBE	12	7	3f
		R_HOLD		6	4	7
		TA		3	2	3
		ASIZE		1	0	0
	}
}

You can add a description of each register field, for example

		SS		31	31	0 0=this is a comment 1=this another comment

Which gets printed.

- register file:

a simple list of register/value pairs, which get parsed from the program.

structure:

registername value comment

with
  registername: name of the register defined in the
                registerdescription file

  value: value of the register

         remark:
           if the regdump program gets a third commandline parameter
           the value gets ignored, and instead the regdump program
           reads the content of the registers address through /dev/mem.

           If this parameter is 8, the program instead prints a list
           of all registers, with the format regname register_address register_size
           (This file can used in u-boot to create a register dump with u-boot
            with the regdump command in u-boot (Todo!). U-Boot should
           print register_name register_value file, which then can be
           passed to the regdump program ... So it is possible to
           compare a U-Boot register setting with a Linux register setting.

If it contains only one column, the registervalue
gets read through /dev/mem.

Example:

CE3CFG	04222310
CE2CFG	08624311


With the above two example files, a regdump prints:

$ ./regdump am1808.reg cmc_reg.reg
--------------------------------------
CE3CFG@68000014 32 bit val: 4222310
SS 0 : 1=look into manual 0=look also into the manual
EW 0
W_SETUP 1
W_STROBE 2
W_HOLD 1
R_SETUP 1
R_STROBE 6
R_HOLD 1
TA 0
ASIZE 0
--------------------------------------
CE2CFG@68000010 32 bit val: 8624311
SS 0 : 1=look into manual 0=look also into the manual
EW 0
W_SETUP 2
W_STROBE 6
W_HOLD 1
R_SETUP 2
R_STROBE 6
R_HOLD 1
TA 0
ASIZE 1

- in testout directory are examples from some boards
- regdump has a self test script, called validate_regdump.sh
  if you change something, please run it!