CMOS.layout guide

CMOS layout

This page explain the workings of the CMOS layout file. The CMOS layout file can be linked into a board specific environment. By creating the cmos.layout file in the board directory. and set the HAVE_OPTION_TABLE in the Kconfig file of the board.

The CMOS layout file must contain the following sections;

• entries
• enumerations
• checksums

The hash (#) character is the comment prefix, all characters until the eof of line are treated as comment.

enumerations section

Each line in the the enumerations section is contructed as follows;

 <config-id>  <value>  <label>

The paramater <config-id> is the same value as the <config-id> from the entries section.

The paramater <value> is the value that get stored at the bit location defined in the entries section, where that config-id is being used.

The paramater <label> is the label for displaying in the the presentation layer.

Example;

 1     0     Disable
 1     1     Enable
 5     0     115200
 5     1     57600
 5     2     38400
 5     3     19200
 5     4     9600
 5     5     4800
 5     6     2400
 5     7     1200

checksums section

The checksums section has one variable with three parameters;

 checksum <startbit> <endbit> <start-of-checksumbit>

The <startbit> parameter is the bit position where the calculation of the checksum starts from.

The <endbit> parameter is the bit position there the calculation of the checksum starts on.

The <start-of-checksumbit> parameter is the bit position there the checksum will be stored, there must be space for 16 bits of checksum data.

Example;

 checksum 392 983 984