Petalinux-Introduction.md

@@ -83,6 +83,18 @@ When Petalinux boots, we need it to automatically configure the USB gadgets, giv
 
 The script can be found [here](https://git.ece.iastate.edu/sd/sdmay23-47/-/blob/master/petalinux/os/project-spec/meta-user/recipes-apps/bootscript/files/bootscript). 
 
+The bootscript requires CyDAQ_comm.elf and CyDAQ_sampling.elf to be in the same directory as it for petalinux to build. These are generated by Vitis. If you are having trouble building Petalinux because these files are missing, you can simply create empty files in their place:
+```bash
+touch ~/sdmay23-47/petalinux/os/project-spec/meta-user/recipes-apps/bootscript/files/CyDAQ_comm.elf
+```
+```bash
+touch ~/sdmay23-47/petalinux/os/project-spec/meta-user/recipes-apps/bootscript/files/CyDAQ_sampling.elf
+```
+> Note: A version of petalinux built with these empty files will not auto start the comm and sampling applications, because they don't exist! It's only useful for getting a working version of Petalinux so you can build the SDK for Vitis. 
+
+More information about building (and copying) those .elf files are in the [Petalinux Repo Setup](https://git.ece.iastate.edu/sd/sdmay23-47/-/wikis/Firmware-Repo-Setup) docs. 
+
+
 # External Resources
 Check out our [Useful Resources](https://git.ece.iastate.edu/sd/sdmay23-47/-/wikis/Useful-Resources) page for links to official documentation and other guides we used to develop this project.