build: simplify cross builds

This patch simplifies seabios cross-builds on !x86 platforms.
It adds a CROSS_PREFIX variable which is used to set CC, LD &
friends to the cross build binaries.  It also moves the common
command definitions up in the Makefile to make sure CC is set
correctly when probing compiler flags using $(call cc-option ...)

Signed-off-by: Gerd Hoffmann <>
1 file changed