Added basic building instructions

BUILDING.md

@@ -0,0 +1,31 @@
+# Building Instructions
+
+All of this is assumed to be on a linux system. Eventually I'll probably make or use some dockerfile that
+has all this installed already.
+
+## Toolchain Installation
+
+### Trellis and FPGA toolchain
+
+First, get an [oss-cad-suite release](https://github.com/YosysHQ/oss-cad-suite-build/releases),
+and unpack it into an install directory of your choice.
+
+Ensure the `bin/` folder is included in your build environment's PATH.
+
+### LiteX
+
+Simply follow the [LiteX quick start guide](https://github.com/enjoy-digital/litex#quick-start-guide).
+
+Ensure that the RISCV toolchain `bin/` folder is also included in your build environment's PATH.
+
+### Rust
+
+TODO will need to install rust and install the rv32/nightly toolchain
+
+### ecpdap (Optional?)
+
+You may or may not have to install your own version of ecpdap, I found the one in `oss-cad-suite` didn't work
+for whatever reason, so I had to install it myself. There are releases on the github, or you can just build it
+yourself with Rust. Just make sure you either replace the binary in the oss-cad-suite location or make sure
+this version of ecpdap has priority in PATH.
+

README.md

@@ -1,10 +1,18 @@
 # Updated Sonar System
 
+Will *not* be doing LVDS system, because arty doesn't have selectable bank voltage to actually use it.
+
+Switching to use Colorlight i9 board (ECP5 UP5K 45), because it has plenty IO broken out, also provides ethernet
+(I just need to implement the magnetics and jack), and is cheaper/potentially easier to acquire for ARVP
+in the future. The LiteX implementation fits in <40% of total resources of the 25K LUT variant, so the 45K
+should be plenty for what I need. Frankly what I'm implementing is very simple. It can probably even handle doing
+the FFT on board if I wanted to.
+
 ## Repo Layout
 
 ```
 hardware/ - Directory for any hardware designs
-  pmod/ - A PMOD interface board, using 4 ADCs with LVDS converters to get data across PMOD
+  pmod/ - A PMOD interface board, using 4 ADCs with LVDS converters to get data across PMOD [Failed Idea]
   sonar_symbols.kicad_sym - custom KiCAD symbols I create for hardware
 ```
 
@@ -71,3 +79,16 @@ Should make sure to have a debug port available as early as possible.
 
 I will make the interface as generic as possible, so it should be easy to swap out, but I
 will start by targetting zmq so I can change as little of the software stack as possible.
+
+
+## Random issues
+
+You will probably need to un write-protect the flash
+
+### ecpdap: "Error: specified probe not found"
+
+A Reboot fixed it....
+
+Do I have ecpdap installed in two places and one of them doesn't work maybe?
+
+I do have two versions installed. one from oss-cad-suite and one by building it manually.