#+title: Gentoo on BeagleV: Fire

* Preface
This guide is written in a way that forces the reader to manually perform every step, excluding environment variables via the setup script because I want to be able to change those. If you would like to follow the official guide provided by beagleboard, which is far more streamlined and automated, please see the references at the bottom of this document.

* Prerequisites

#+begin_src bash :noeval
emerge -a sys-block/bmap-tools sys-fs/genimage dev-libs/libyaml sys-fs/mtools
mkdir beaglev-fire-gentoo && cd beaglev-fire-gentoo
# deploy will contain any output files, images, etc
mkdir deploy
#+end_src

** Using the riscv toolchain provided via crossdev

Crossdev is required for this step. If you don't have crossdev set up, use [[https:https://wiki.gentoo.org/wiki/Crossdev][this]] guide to install it. At the time of writing this installs riscv64-unknown-linux-gnu-gcc 13.2.1. This is note worthy because the official guide uses 11.4. If there are issues with this toolchain, use the precompiled toolchain via [[*Using a precompiled toolchain][these steps]].

#+begin_src bash
crossdev -t riscv64-unknown-linux-gnu
export RISCV64_CC="riscv64-unknown-linux-gnu-"
#+end_src

** Using a precompiled toolchain

#+begin_src bash
mkdir mirror
mkdir toolchain
export GCC_VERSION=11.4.0
wget -c --directory-prefix=./mirror/ "https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/${GCC_VERSION}/x86_64-gcc-${GCC_VERSION}-nolibc-riscv64-linux.tar.xz"

tar xvf ./mirror/x86_64-gcc-${GCC_VERSION}-nolibc-riscv64-linux.tar.xz --strip-components=2 -C ./toolchain/
export RISCV64_CC="$PWD/toolchain/bin/riscv64-linux-"
#+end_src

From this point forward, instructions will use the ~RISCV64_CC~ variable as the toolchain.

Export some other misc. environment variables:
#+begin_src bash
export HSS_BRANCH="v2023.02"
export HSS_REPO="https://github.com/polarfire-soc/hart-software-services.git"
export UBOOT_BRANCH="linux4microchip+fpga-2023.02"
export UBOOT_REPO="https://github.com/polarfire-soc/u-boot.git"
export GIT_DEPTH=20
export CORES=$(getconf _NPROCESSORS_ONLN)
#+end_src

* Clone & Build Heart Software Services (HSS)
** Clone HSS
#+begin_src bash
# remove old if it exists, optional
if [ -d ./hart-software-services/ ] ; then
	rm -rf ./hart-software-services/ || true
fi
git clone -b ${HSS_BRANCH} ${HSS_REPO} ./hart-software-services/ --depth=${GIT_DEPTH}
#+end_src

** Build HSS
#+begin_src bash
make -C hart-software-services/tools/hss-payload-generator/ clean
make -C hart-software-services/tools/hss-payload-generator/
cp -v ./hart-software-services/tools/hss-payload-generator/hss-payload-generator ./deploy/
#+end_src

* Clone & Build u-boot
** Clone u-boot
#+begin_src bash
# remove old if it exists, optional
if [ -d ./u-boot ] ; then
	rm -rf ./u-boot || true
fi
git clone -b ${UBOOT_BRANCH} ${UBOOT_REPO} ./u-boot/ --depth=${GIT_DEPTH}
#+end_src

** Download the patches

The patches currently exist as part of BeagleV's ~BeagleV-Fire-ubuntu~ repo, so we'll just clone the whole thing for now. Eventually, I'll see if I can mirror just the patches somewhere.

#+begin_src bash
git clone https://git.beagleboard.org/beaglev-fire/BeagleV-Fire-ubuntu.git ./beaglev --depth=${GIT_DEPTH}
#+end_src


** Build u-boot
#+begin_src bash
# Apply patches to uboot
cp -v ./patches/u-boot/beaglev-fire/microchip_mpfs_icicle.h ./u-boot/include/configs/microchip_mpfs_icicle.h
cp -v ./patches/u-boot/beaglev-fire/microchip-mpfs-icicle-kit.dts ./u-boot/arch/riscv/dts/
cp -v ./patches/u-boot/beaglev-fire/microchip_mpfs_icicle_defconfig ./u-boot/configs/microchip_mpfs_icicle_defconfig
make -C u-boot ARCH=riscv CROSS_COMPILE=${RISCV64_CC} microchip_mpfs_icicle_defconfig
# if you want to make configurations....
# make -C u-boot ARCH=riscv CROSS_COMPILE=${RISCV64_CC} menuconfig
make -C u-boot ARCH=riscv CROSS_COMPILE=${RISCV64_CC} olddefconfig
make -C u-boot ARCH=riscv CROSS_COMPILE=${RISCV64_CC} savedefconfig
cp -v ./u-boot/defconfig ./u-boot/configs/microchip_mpfs_icicle_defconfig
cp -v ./u-boot/defconfig ./patches/u-boot/beaglev-fire/microchip_mpfs_icicle_defconfig
make -C u-boot -j${CORES} ARCH=riscv CROSS_COMPILE=${RISCV_CC} all
# copy the generated uboot into our deploy folder
cp -v ./u-boot/u-boot.bin ./deploy/
# i have no idea why 2 copies are being made, one u-boot.bin and one src.bin
cp -v ./u-boot/u-boot.bin ./deploy/src.bin
#+end_src

* Build the Linux kernel
* Generate the HSS payload
* Gentoo