I am unable to compile the preloader for GHRD build, Please help!

I’m running intel quartus prime standard edition (18.1), and intel SoC EDS (18.0), both with free evaluation licenses. I am trying to build the cyclone V GHRD. I follow the rocketboards.org procedure to compile the hardware design, and generate the preloader, but when I try to compile the preloader in the SoC EDS command shell I get this message:

nferguson@D14NFergusonDT ~/Desktop/DE10_NANO_SoC_GHRD/software/spl_bsp

$ make

tar zxf /cygdrive/c/intelFPGA/18.1/embedded/host_tools/altera/preloader/uboot-socfpga.tar.gz

tar: Error opening archive: Failed to open ‘/cygdrive/c/intelFPGA/18.1/embedded/host_tools/altera/preloader/uboot-socfpga.tar.gz’

make: *** [uboot-socfpga/.untar] Error 1

Here are links to the design flow I am following:

https://rocketboards.org/foswiki/Documentation/AVCVGSRDLTS

https://rocketboards.org/foswiki/Documentation/GSRDPreloader

https://rocketboards.org/foswiki/Documentation/AVGSRDCompileHardwareDesign

I would very grateful for any help or advice. Thanks!