#!/bin/ksh

# This file and its contents are supplied under the terms of the
# Common Development and Distribution License ("CDDL"), version 1.0.
# You may only use this file in accordance with the terms of version
# 1.0 of the CDDL.
#
# A full copy of the text of the CDDL should have accompanied this
# source. A copy of the CDDL is also available via the Internet at
# http://www.illumos.org/license/CDDL.

# Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
# Copyright 2025 Oxide Computer Company

# A simple update script that checks out the upstream AMD firmware
# repository, extracts the microcode into separate files within the amd/
# directory, generates the required combined equivalence table and updates
# the pkg(7) manifest.

UPSTREAM=git://git.kernel.org
UPSTREAM_PATH=/pub/scm/linux/kernel/git/firmware/linux-firmware.git

# These are the GPG keys that AMD use to sign their CPU microcode updates
# The first key is the current one and the second is one they have used for
# older CPU families.
GPGSERVER=keys.gnupg.net
typeset -a GPGKEYS=(
	0xFC7C6C505DAFCC14718357CAE4BE5339F328AE73
	0x916A770823A7B27AADE01565A5E8DBC98C0108B4
)

function errexit {
	echo "$@" >&2
	exit 1
}

FW=platform/amd64/ucode/AuthenticAMD

export LC_ALL=C.UTF-8

set -e
set -o pipefail

mf=../../pkg/manifests/system-microcode-amd.p5m
[[ -f $mf ]] || errexit "Run from usr/src/data/ucode"

function find_cmd {
	typeset cmd="$1"
	typeset var=$(echo $cmd | tr '[:lower:]' '[:upper:]')
	typeset -n path="$var"
	path=$(whence -fp "$cmd")
	if (($? != 0)) || [ ! -x "$path" ]; then
		errexit "Cannot find executable '$cmd' in PATH"
	fi
}

# This script uses a few commands which are not part of illumos and are
# expected to be available in the path.
find_cmd git
find_cmd gpg
find_cmd pkgfmt
find_cmd stat
find_cmd xxd
# Search for 'ucodeadm'. If you need to use an updated ucodeadm to handle this
# firmware update, as is occasionally necessary, ensure it occurs earlier in
# the path than /usr/sbin.
find_cmd ucodeadm

tmp=$(mktemp -d)
[[ -n "$tmp" && -d "$tmp" ]]
mkdir $tmp/out || errexit "Failed to create temporary directory"
trap 'rm -rf $tmp' EXIT

echo "** Adding AMD GPG signing keys to temporary keyring"
mkdir -m 0700 $tmp/gnupg
$GPG --homedir $tmp/gnupg --keyserver $GPGSERVER --receive-keys ${GPGKEYS[@]}

echo "** Cloning $UPSTREAM$UPSTREAM_PATH"
$GIT clone $UPSTREAM$UPSTREAM_PATH $tmp/ucode

ver=`$GIT -C $tmp/ucode log -n1 --format=%ad --date=format:%Y%m%d amd-ucode`
echo "** Updating to microcode version $ver"

echo "** Verifying microcode signatures"
for f in $tmp/ucode/amd-ucode/*.bin; do
	if [[ ! -f "$f.asc" ]]; then
		echo "Signature missing for ${f##*/}"
		exit 1
	fi
	$GPG --homedir $tmp/gnupg --trust-model=always --verify $f{.asc,}
done

# Now that everything is in place and verified, begin modifying the tree.

rm -f amd/*-*

cp $tmp/ucode/LICENSE.amd-ucode amd/THIRDPARTYLICENSE
echo AMD Processor Microcode Data Files > amd/THIRDPARTYLICENSE.descrip

for f in $tmp/ucode/amd-ucode/*.bin; do
	bf=${f##*/}
	bf=${bf#microcode_}
	bf=${bf%.bin}
	[[ $bf = amd* ]] || errexit "$f does not look like a firmware file"
	echo
	echo "*** Converting $bf"
	echo
	mkdir $tmp/out/$bf
	cp $f $tmp/amd-fw
	$UCODEADM -l $tmp/amd-fw
	$UCODEADM -i -R $tmp/out/$bf $tmp/amd-fw
	rm -f $tmp/amd-fw
done

# Copy the firmware files into place
cp $tmp/out/*/*-?? amd/

# Deal with fallback firmware files (see amd/fallback/README)
# For some processors AMD ship two microcode versions. One that can only be
# loaded on systems which are already at a particular firmware level and an
# older fallback one for systems that running old firmware. They package both
# of these in the same microcode bundle with nothing to differentiate them
# apart from their revision number. The older version occurs first in the
# bundle. On illumos the newer version is always tried first and the older
# version only used if that is not accepted by the processor. This script
# looks for instances of more than one microcode for a CPU and moves the older
# version into the amd/fallback directory. Anyone using this tool to prepare a
# PR is expected to make judicious use of "git" and "ucodeadm" to verify that
# everything looks reasonable afterwards.

function ucode_version {
	printf "0x%s" $($UCODEADM -t amd -l $1 | tr -s ' ' |
	    awk -F'[ =]' '$4 == "Patch" {print $5}')
}

echo
echo "** Relocating fallback microcode"
echo

for f in amd/*-01; do
	bf=$(basename $f -01)
	[[ -f "amd/$bf-00" ]] || errexit "$f has no -00 variant"
	mv -f amd/$bf-00 amd/fallback/
	mv amd/$bf-{01,00}
	# Verify that the fallback version is lower than the main just in case
	# AMD reverse the order of the patches for any reason.
	typeset -i fbver=$(ucode_version amd/fallback/$bf-00)
	typeset -i mlver=$(ucode_version amd/$bf-00)
	printf "    %s - %X / %X\n" $bf $mlver $fbver
	(( mlver > fbver )) || errexit "$bf - fallback is newer"
done

# Combine the equivalence tables from the different updates into one.
# Each equivalence-table file is a sequence of 16-byte records with a
# 16-byte terminator which is all zeros. To merge, we just concatenate
# the unique non-terminator records and then add 16 bytes from /dev/zero.
{
	for f in $tmp/out/*/equivalence-table; do
		size=$($STAT -c %s $f)
		((size -= 16))
		dd if=$f bs=1 count=$size status=none
	done | $XXD -c16 | cut -d\  -f2- | sort -u | $XXD -r -p
	# Add terminator
	dd if=/dev/zero bs=1 count=16 status=none
} > amd/equivalence-table

$PKGFMT -u $mf
mv $mf $mf.tmp
egrep -v "file path=$FW" $mf.tmp > $mf
rm -f $mf.tmp

for f in amd/*-*; do
	[[ -f $f ]] || continue
	bf=${f##*/}
	echo "file path=$FW/$bf group=sys mode=0444 reboot-needed=true" >> $mf
done

for f in amd/fallback/*-*; do
	bf=${f##*/}
	echo "file path=$FW/fallback/$bf"\
           "group=sys mode=0444 reboot-needed=true" >> $mf
done

sed -i "/pkg.fmri.*microcode\/amd@/s/@[0-9]*/@$ver/" $mf

$PKGFMT -fv2 $mf