[gentoo-user] How to compile for less bits :)

Hi,

 I asking in beforehand, to prevent the search for spurious
 unexplainable errors which may be hardly to detect.

 For my microcontroller board (ATMEL AT81RM920, linux based) I want
 to crosscompile kernels and applications on my 64bit Gentoo linux.
 The source of a gcc (prepared on a 32bit system I fear) for the
 purpose of crosscompiling from a 32bit system-- target is the above
 mentioned processor -- is available.

 Is it possible to compile this gcc as a 32bit-application on my 64bit
 system to ensure the same behaviour as it would if ot was built on a
 "original 32bit Gentoo Linux"?

 (And in this context: The audio application "chuck" is only as 32bit
 application available currently. How is it possible to compile this
 on a 64bit system?)

 Thank you very much in advance for any help!

 Best regards
 mcc