Firmwares/README.md

# MINRES Firmware Repository
## Structure
This repository comes with several executables ready to be built, such as `hello-world` or `coremark` and `dhrystone` in the `benchmark` directory.
Creating the executables in the easiest way possible is done by calling `make`in the corresponding directory.

## Prerequisite
This repository requires `riscv64-unknown-elf-gcc` to be located in `$PATH`.

## How to Use
When compiling executables, the target platform needs to be specified using the 'BOARD' variable. When compiling for the TGC5C for example, use  `make BOARD=tgc_vp`, when compiling for RTL `make BOARD=rtl`. The default value for the Board variable is 'iss'.
The arch can be set with the 'ISA' variable, the default value is 'imc'.

When compiling for the TGC5A VP for example, the call to create the correct binary is the following:
```
make BOARD=tgc_vp ISA=e
```
## Useful information
Using `bear -- <build-command>` will cause a compile_commands.json to be emitted. This allows using completion tools like clangd. 

## Current Limitations
Currently, this repository only supports creation of 32-bit executables (Even when setting the `RISCV_ARCH` and `RISCV_ABI` manually).

Compiling for the 'e' extension / ISA together with any other extension (`ISA=emc` for example), requires setting the `RISCV_ABI=ilp32e` explicitly. 

When switching ABI or ARCH ensure that object files in the corresponding 'env' dir in the 'bare-metal-bsp' submodule are removed, so they get created with the appropriate flags (namely the 'init.o' file).