diff -r 7c4a911dc066 -r 541af5ee3ed9 sbsv1/abld/doc/zephyr_buildrom_changes.txt --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/sbsv1/abld/doc/zephyr_buildrom_changes.txt Wed Aug 18 17:23:33 2010 +0300 @@ -0,0 +1,33 @@ +Zephyr/Cedar BUILDROM +2003/09/03 + +BUILDROM has been extended to support the building of 'mostly-thumb' ROMs and mixed ROMs. + +1. Mostly Thumb ROMs. + +In Cedar for Zephyr BUILDROM supports the following macros for +specifying which build to construct the ROM from: + _ARM4 - The ARM4 build (eventually this will be removed) + _ARM4T - The 'mostly-thumb' ARM4T. + +2. Mixed ROMs + +Mixed ROMs have a kernel built for a different ABI than that targeted +by user-side code. In practice this means an EABI kernel and GCC98r2 +user-side code. By default BUILDROM use the same ABI for the kernel as +specified for user-side code (i.e. one of ARM4 or ARM4T). The default +kernel ABI can be overriden by supplying the appropriate value for +_KABI in BUILDROM's commandline e.g. -D_KABI=ARMV5. + +The following example builds a 'mostly thumb' techview ROM with an +EABI kernel compiled specifically for XScale: + + buildrom lubbock -D_ARM4T -D_KABI=XSCALE -o\epoc32\techview.arm4t.xscale.img \epoc32\rom\include\techview + +The above example shows that the EABI kernel does not have to be the +default ARMV5 build. BUILDROM supports customizations of the default +ARMV5 build. It is also worth noting that the XScale build does not +have to be complete. If BUILDROM cannot find an XScale file it will +look for the equivalent file from the build that has been +customized. Currently this will always be ARMV5, since this is the +only build that supports customization at this time.