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nvram-wakeup.conf - the configuration file for NVRAM WakeUp.

nvram-wakeup.conf(5) NVRAM WakeUp nvram-wakeup.conf(5)


nvram-wakeup.conf - the configuration file for NVRAM WakeUp.


This file can be passed to the program NVRAM WakeUp (see nvram-wakeup(8) for more information) via the --configfile option.
It might look as follows:
# nvram-wakeup.conf
#  This is an example configuration for MSI MS-6351
need_reboot = ON_ANY_CHANGE # All changes take effect   # after a reboot
addr_chk_h = 0x30 # These are adresses of addr_chk_l = 0x31 # the checksum bytes
addr_stat = 0x55 # Status byte shift_stat = 3 # The position of the   # status bit in the byte
addr_day = 0x56 # Day and time addr_hour = 0x57 addr_min = 0x58 addr_sec = 0x59


Anything after and including a # character is treated as a comment and is ignored.
The options must have the form NAME = VALUE with or without spaces before NAME, after VALUE or around the equal sign. Valid options are described below.
The options may appear in any order. The same option must not appear twice.


bcd = (ON|OFF), default OFF
indicates if the board uses BCD notation for storing values.
BCD is the so called Binary Coded Decimal notation (actually, it is `packed BCD', in the plain BCD they waste whole byte per digit.) in this notation the decimal numbers 0..99 are stored using four bits for every digit, e.g. 24 would be stored as 0x24 (the 4 is stored in the lower four bits and the 2 is stored in the upper four bits).
Addresses of the bytes where the checksum (lower resp. higher bytes), status (enabled/disabled), month, day, hour, minute and second are stored in the nvram.
addr_chk_h, addr_chk_l and addr_stat must be defined. All other may stay undefined. That means, the board doesn't store them (e.g. because it stores that value in RTC alarm registers)
There are some boards which have two checksums. Since I haven't seen many of them yet, I don't know if they need special handling
The address of the byte containing a weekday vector. Currently, I know of only two boards, which store a weekday vector (Asus SP98-X and SP97-X).
rtc_time = (ON|OFF), default: OFF
similar to addr_mon/addr_day, but stored in BCD and not affecting the checksum. In most cases, the day is stored in the RTC register D (0x7F), but there are also some boards, which store it somewhere in the nvram (address <= 0x71).
If rtc_day is >= 0x72, you will need a kernel patch: in <kernel-src>/drivers/char/nvram.c change the line
#define NVRAM_BYTES 128
in newer kernels (beginning with 2.4.20) it is the line
which must be changed to
#define NVRAM_BYTES 128
reset_mon = (ON|OFF), default: OFF
reset_day = (ON|OFF), default: OFF
on some boards we have to set the value of rtc_mon resp. rtc_day to 0 when disabling the wakeup feature.
nr_stat = 1 (just on/off)
nr_mon = 4 ( 0..12 )
nr_day = 5 ( 0..31 )
nr_rtc_mon = 5 (0x00...0x12)
nr_rtc_day = 6 (0x00...0x31)
nr_wdays = 7 ( 1 per day )
nr_hour = 5 ( 0..23 )
nr_min = 6 ( 0..59 )
nr_sec = 6 ( 0..59 )
Number of bits needed for the status, month, day, rtc_day, weekday vector, hour, minute and second. These values are a priori motherboard independent but depend on the BCD/non-BCD notation.
Indicates, by how many bits the value is shifted to the left in the byte, e.g. the value of the day (5 bits) could be stored in the bits marked with an "x" of a byte:
000xxxxx -> shift_day = 0
00xxxxx0 -> shift_day = 1
0xxxxx00 -> shift_day = 2
xxxxx000 -> shift_day = 3
default: OFF
Here "..." means any or-ed combination of multiple ON_XXX values.
Some boards need a reboot for changes in nvram to take effect. Some of them need a reboot after _any_ change, some of them only after the status bit was changed. Anyway, now we are able to define when a board needs a reboot:
means, the board never needs it
means, the board needs it after _any_ change on nvram.
means, reboot only if the status bit is changed
means, reboot whenever the status or the second are changed.
The idea behind this is if nvram-wakeup decides that we need to reboot, it will exit with exit status 1 (instead of 0). So the script which runs nvram-wakeup could react on this. We also print it to stderr, so if nvram-wakeup is run directly on the command line, the user could react appropriately.
indicates if upper nvram must be used and if yes, which method to use to access it. Note that upper nvram can only be read if --directisa parameter is specified. Possible values:
upper nvram disabled (default)
access upper nvram by a method used by most (if not all) Intel chipsets with ICH, ICH2, C-ICH, ...
(datasheets at
access upper nvram by a method used by the Dallas Semiconductor DS1685/DS1687 chips.
(datasheet at
access upper nvram by a method used by VIA's VT82C686A "Super South" South Bridge. Reported to work with VT82C686A, VT82C686B, VT82C596, nVidia nForce2, ATI RADEON 9100 IGP (= RS300), AMD-8111.
(datasheet at
(datasheet at
access upper nvram by a method used by VIA's VT8235/37 South Bridges. Reported to work with VT8233 as well.
(no official source)
chk_method = (DELL|FSC), default: undefined
indicates which algorithm for calculation of the checksum must be used. Possible values:
Majority of mainboards use the same algorithm (just addition of values). This algorithm is used if no chk_method option is specified.
This method is used by many Dell mainboards (addition of negative values).
Fujitsu-Siemens uses yet another algorithm. I don't know it and they consider it as a company secret. Thus this method is not implemented.


rtc_mon_0_is_c0 = (ON|OFF), default: OFF
rtc_day_0_is_c0 = (ON|OFF), default: OFF
on some boards we have to store the value 0xC0 instead of 0 in rtc_mon resp. rtc_day. If you use one of this two options, don't forget to set nr_rtc_mon resp. nr_rtc_day to 8.
on some boards the value of addr_day is split over the day and the status byte. In those cases the lower day_hack bits of the day value are stored in the highest bits of the status byte and the rest is stored in the day byte.
day_no_bcd = (ON|OFF), default: OFF
on some boards the value of addr_day is not stored in BCD, although everything else is. This option has no effect is the option bcd is not enabled.





Written by Sergei Haller <>.


Report bugs at the bug tracking system (see HOMEPAGE) or on the mailing list Copyright © 2001-2004 Sergei Haller.
Jan 16 2004 Linux