Well, I wanted to compile u-boot with i2c support. So I just added an #include <i2c.h> in to my boards board.c, put #define CFG_HARD_I2C in the include-file and thought that'd be enough.
Well... apparently that's not enough as compiling (make distclean done before) stops in the linking process with a lot of complaints like this:
common/libcommon.a(cmd_i2c.o)(.text+0x128): In function `do_i2c_md': /opt/asemann/u-boot/common/cmd_i2c.c:188: undefined reference to `i2c_read'
and the error
common/libcommon.a(exports.o)(.got2+0x24):/opt/asemann/u-boot/common/exports.c:14: undefined reference to `i2c_read'
So... any suggestions where to add some references so it find all the stuff? I tried to figure out what other boards that use i2c do, but couldn't find any hints that I missed some Makefile or config, got lost in the build-system.
Peter Asemann