from README file:

There are two classes of configuration variables:

* Configuration _OPTIONS_: These are selectable by the user and have names beginning with "CONFIG_".

* Configuration _SETTINGS_: These depend on the hardware etc. and should not be meddled with if you don't know what you're doing; they have names beginning with "CONFIG_SYS_".

historically, i've always understood (from kernel stuff) that macros that begin with "CONFIG_" should *always* be user-selectable through the Kbuild system. so i'm not sure how to interpret a "CONFIG_SYS_" prefix.

i ask given a couple examples i just ran across. first, this regarding the macro "CONFIG_MAC_OFFSET":

board/cm5200/cm5200.c: if (i2c_read(CONFIG_SYS_I2C_EEPROM, CONFIG_MAC_OFFSET, 2, buf, 6) == 0) { board/cm5200/cm5200.c: CONFIG_MAC_OFFSET); include/configs/cm5200.h:#define CONFIG_MAC_OFFSET 0x35 /* MAC address offset in I2C EEPROM */

to me, that *clearly* should not have used "CONFIG_MAC_OFFSET", but rather just "MAC_OFFSET."

the second example, though, is not quite as clear:

board/pdm360ng/pdm360ng.c: CONFIG_SYS_I2C_EEPROM_MAC_OFFSET, 1, buf, 6); board/pdm360ng/pdm360ng.c: CONFIG_SYS_I2C_EEPROM_MAC_OFFSET); include/configs/pdm360ng.h:#define CONFIG_SYS_I2C_EEPROM_MAC_OFFSET 0x10

so even though this second example is also not defined by the Kbuild system, is it somehow more acceptable because it begins with "CONFIG_SYS_"? i'm having trouble appreciating the distinction.

rday