Just posting an update on the current Cygwin issues with U-Boot and the Android NDK.

I do have NDK cross-compiles of tools-only working well from a Linux environment now but on Cygwin there continues to be some major compatibility issue with U-Boot's KBuild system and the Android NDK.

Using the same command-line as my Linux NDK cross-compile on Cygwin results in the following odd build error:

HOSTCC  scripts/basic/fixdep   CHK     include/config/uboot.release   CHK     include/generated/version_autogenerated.h   CHK     include/generated/timestamp_autogenerated.h   UPD     include/generated/timestamp_autogenerated.h   HOSTCC  tools/gen_eth_addr : No such file or directoryg file: make[1]: *** [scripts/Makefile.host:97: tools/gen_eth_addr] Error 2 make[1]: *** Deleting file 'tools/gen_eth_addr' make: *** [Makefile:1722: tools-only] Error 2

Then seeing if adding --sysroot helps gives the following also-bizarre error:

HOSTCC  scripts/basic/fixdep   CHK     include/config/uboot.release   CHK     include/generated/version_autogenerated.h   CHK     include/generated/timestamp_autogenerated.h   UPD     include/generated/timestamp_autogenerated.h   HOSTCC  tools/gen_eth_addr In file included from ././include/compiler.h:19:0,                  from <command-line>:0: g:\cygwin\home\chris\x-tools\arm-linux-androideabi-r15c-api21-unified\lib\gcc\arm-linux-androideabi\4.9.x\include\stdint.h:9:26: fatal error: stdint.h: No such file or directory  # include_next <stdint.h>                           ^ compilation terminated. make[1]: *** [scripts/Makefile.host:97: tools/gen_eth_addr] Error 1 make: *** [Makefile:1722: tools-only] Error 2

I'll be uploading a patch to fix issues with tools-only native Cygwin compiles and Android NDK cross-compiles on Linux shortly, but Android NDK cross-compiles on Cygwin could definitely still use some attention beyond my ability.

Thanks for you for your time!