It sounds like there are several issues here, and a lot of pain. I’m curious as to how long it takes other people to complete the process too. As a preface, this entire process takes me about 40 minutes on a 30Mbs cable modem and a Intel Core i3 3.5GHz host PC. This includes installing and building all programs and samples. I don’t work for NVIDIA, I’m just curious.
JetPack is a ~ 15MB file, it seems like there were issues if it took you 2 hours to download it, and then only two hours to download the rest of the packages which in aggregate is multiple gigabytes. Maybe parallel download would help, I don’t know.
In this process, L4T is not ‘compiled’. There’s actually a different process going on. Simplistically what happens is that prior to flashing the Jetson, a system image is built on the host which is to be placed on the Jetson bit for bit on the eMMC. It takes a while to build the image, which is dependent on the speed of the host computer and host disk. On my machine, it takes about 2-3 minutes for the ‘Installing’ step, which not only includes preparing the image for flashing, but also installing the Tegra tools, like the debugger and PerfKit. Are you using a virtual machine per chance?
Most of these files are packaged as .deb files, so having a PPA isn’t going to make it much (if any) faster.
2 hours to install CUDA and samples seems like a long time.
Installing drivers is a big pain, that’s why the Grinch kernel is popular. However, I’ll note that you don’t have to recompile the whole kernel to build drivers or modules. You only have to build the modules and kernels themselves, though you will need the kernel source code.
The entire JetPack process for me takes less time than it did to originally transfer the system image to flash the Jetson in the earlier 19.X releases. During development, once everything is downloaded and the samples are ignored, it usually takes less than 10 minutes to reflash.
Here’s a video of the installation process for comparison. In real time, it took 44 minutes. I did not build any vagrants, so that time isn’t added in the total. In the video, I obviously sped up some of the less interesting download and installation sequences: