Baremetal create img file from axf

I don't want to use DS5 because I don't have a license.

If I compiled a baremetal app using makefile, the output file is hello.axf. The make file is from one of the prebuilt apps in quartus "quartus/embedded\examples\software"

I want to convert the axf file to img so that I can copy it to the SD card. I could successfully compile and run the preloader on the card. The UBOOT is also ok and I could boot linux kernel angestrom.

I believe it can be done because the UBOOT itself is a baremetal app.

The board is DE1-SOC.

Thanks