93 lines
3.7 KiB
Plaintext
93 lines
3.7 KiB
Plaintext
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<<<
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:sectnums:
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== Software Toolchain Setup
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To compile (and debug) executables for the NEORV32 a RISC-V toolchain is required.
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There are two possibilities to get this:
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1. Download and _build_ the official RISC-V GNU toolchain yourself.
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2. Download and install a prebuilt version of the toolchain; this might also done via the package manager / app store of your OS
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[NOTE]
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The default toolchain prefix (`RISCV_PREFIX` variable) for this project is **`riscv32-unknown-elf-`**. Of course you can use any other RISC-V
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toolchain (like `riscv64-unknown-elf-`) that is capable to emit code for a `rv32` architecture. Just change `RISCV_PREFIX`
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according to your needs.
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:sectnums:
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=== Building the Toolchain from Scratch
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To build the toolchain by yourself you can follow the guide from the official https://github.com/riscv-collab/riscv-gnu-toolchain GitHub page.
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You need to make sure the generated toolchain fits the architecture of the NEORV32 core. To get a toolchain that even supports minimal
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ISA extension configurations, it is recommend to compile for `rv32i` only. Please note that this minimal ISA also provides further ISA
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extensions like `m` or `c`. Of course you can use a _multilib_ approach to generate toolchains for several target ISAs at once.
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.Preparing GCC build for `rv32i` (minimal ISA)
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[source,bash]
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----
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$ git clone https://github.com/riscv/riscv-gnu-toolchain
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$ cd riscv-gnu-toolchain
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$ riscv-gnu-toolchain$ ./configure --prefix=/opt/riscv --with-arch=rv32i --with-abi=ilp32
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$ riscv-gnu-toolchain$ make
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----
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[IMPORTANT]
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Keep in mind that - for instance - a toolchain build with `--with-arch=rv32imc` provides library code (like the C
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standard library) compiled entirely utilizing compressed (`C`) and `mul`/`div` instructions (`M`). Hence, this
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code CANNOT be executed (without emulation) on an architecture that does not support these ISA extensions.
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:sectnums:
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=== Downloading and Installing a Prebuilt Toolchain
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Alternatively, you can download a prebuilt toolchain.
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:sectnums:
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==== Use The Pre-Built Toolchains
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We have compiled several GCC toolchains on a 64-bit x86 Ubuntu (Ubuntu on Windows, actually) and uploaded it to
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GitHub. You can directly download the according toolchain archive as single _zip-file_ within a packed
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release from https://github.com/stnolting/riscv-gcc-prebuilt. More information about downloading and installing
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these prebuilt toolchains can be found in the repository's README.
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:sectnums:
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==== Use a Third Party Toolchain
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Of course you can also use any other prebuilt version of the toolchain. There are a lot RISC-V GCC packages out there -
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even for Windows. On Linux system you might even be able to fetch a toolchain via your distribution's package manager.
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[IMPORTANT]
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Make sure the toolchain can (also) emit code for a `rv32i` architecture, uses the `ilp32` or `ilp32e` ABI and **was not build** using
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CPU extensions that are not supported by the NEORV32 (like `D`).
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:sectnums:
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=== Installation
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Now you have the toolchain binaries. The last step is to add them to your `PATH` environment variable (if you have not
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already done so): make sure to add the _binaries_ folder (`bin`) of your toolchain.
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[source,bash]
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----
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$ export PATH=$PATH:/opt/riscv/bin
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----
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You should add this command to your `.bashrc` (if you are using bash) to automatically add the RISC-V
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toolchain at every console start.
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:sectnums:
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=== Testing the Installation
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To make sure everything works fine, navigate to an example project in the NEORV32 example folder and
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execute the following command:
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[source,bash]
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----
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neorv32/sw/example/demo_blink_led$ make check
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----
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This will test all the tools required for generating NEORV32 executables.
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Everything is working fine if `Toolchain check OK` appears at the end.
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