feature: script to build my own kernel and rootf

Makefile

@@ -1,4 +1,4 @@
-.PHONY: build run ci get-alpine-rootfs
+.PHONY: build run ci
 .EXPORT_ALL_VARIABLES:
 
 GOARCH=amd64
@@ -11,7 +11,7 @@ GOBUILDFLAGS=-tags dev
 
 EXEC=out/main
 
-build: out/alpine-minirootfs-3.19.0-x86_64.tar.gz $(EXEC)
+build: $(EXEC)
 
 run: $(EXEC)
 	@chmod +x $(EXEC)
@@ -20,8 +20,6 @@ run: $(EXEC)
 ci:
 	golangci-lint run --fix
 
-get-alpine-rootfs: out/alpine-minirootfs-3.19.0-x86_64.tar.gz
-
 publish:
 	scp $(EXEC) sf314:~/firecracker/
 
@@ -32,6 +30,3 @@ dependencies:
 $(EXEC): cmd/main.go dependencies
 	@echo "build for os $$GOOS and arch $$GOARCH"
 	go build -o $@ -ldflags="$(LDFLAGS)" $(GOBUILDFLAGS) $<
-
-out/alpine-minirootfs-3.19.0-x86_64.tar.gz:
-	wget -O $@ https://dl-cdn.alpinelinux.org/alpine/v3.19/releases/x86_64/alpine-minirootfs-3.19.0-x86_64.tar.gz

cmd/main.go

@@ -109,6 +109,12 @@ func setupEnv() int {
 				StaticConfiguration: &firecracker.StaticNetworkConfiguration{
 					MacAddress:  "06:00:AC:10:00:02",
 					HostDevName: tap.Link.Attrs().Name,
+					/*					IPConfiguration: &firecracker.IPConfiguration{
+										IPAddr:      tapNetwork,
+										Gateway:     firstIpTapNetwork,
+										Nameservers: []string{"1.1.1.1"},
+										IfName:      "net1",
+									},*/
 				},
 			},
 		},
@@ -125,6 +131,9 @@ func setupEnv() int {
 			firecracker.VMCommandBuilder{}.
 				WithBin("firecracker").
 				WithSocketPath("/tmp/firecracker.socket").
+				//WithStdin(os.Stdin).
+				//WithStdout(os.Stdout).
+				//WithStderr(os.Stderr).
 				Build(ctx),
 		),
 		firecracker.WithLogger(logrus.NewEntry(log)),
@@ -149,6 +158,19 @@ func setupEnv() int {
 		return 1
 	}
 
+	/*	cmd := exec.Command("/bin/sh")
+
+		cmd.Stdin = os.Stdin
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+
+		cmd.Env = []string{"PS1=-[ns-process]- # "}
+
+		if err := cmd.Run(); err != nil {
+			fmt.Printf("Error running the /bin/sh command - %s\n", err)
+			os.Exit(1)
+		}*/
+
 	return 0
 }
 

rootf-kernel/Makefile

@@ -0,0 +1,6 @@
+.PHONY: get-alpine-rootfs
+
+get-alpine-rootfs: out/alpine-minirootfs-3.19.0-x86_64.tar.gz
+
+out/alpine-minirootfs-3.19.0-x86_64.tar.gz:
+	wget -O $@ https://dl-cdn.alpinelinux.org/alpine/v3.19/releases/x86_64/alpine-minirootfs-3.19.0-x86_64.tar.gz

rootf-kernel/kernel-config/fs.config

@@ -0,0 +1,2 @@
+CONFIG_EXT4_FS=y
+CONFIG_OVERLAY_FS=y

rootf-kernel/kernel-config/net.config

@@ -0,0 +1,158 @@
+CONFIG_VETH=y
+CONFIG_BRIDGE=y
+CONFIG_VXLAN=y
+
+CONFIG_IP_SET=y
+CONFIG_IP_SET_BITMAP_IP=y
+CONFIG_IP_SET_BITMAP_IPMAC=y
+CONFIG_IP_SET_BITMAP_PORT=y
+CONFIG_IP_SET_HASH_IP=y
+CONFIG_IP_SET_HASH_IPMARK=y
+CONFIG_IP_SET_HASH_IPPORT=y
+CONFIG_IP_SET_HASH_IPPORTIP=y
+CONFIG_IP_SET_HASH_IPPORTNET=y
+CONFIG_IP_SET_HASH_IPMAC=y
+CONFIG_IP_SET_HASH_MAC=y
+CONFIG_IP_SET_HASH_NETPORTNET=y
+CONFIG_IP_SET_HASH_NET=y
+CONFIG_IP_SET_HASH_NETNET=y
+CONFIG_IP_SET_HASH_NETPORT=y
+CONFIG_IP_SET_HASH_NETIFACE=y
+CONFIG_IP_SET_LIST_SET=y
+
+CONFIG_NETFILTER=y
+CONFIG_NETFILTER_ADVANCED=y
+CONFIG_NETFILTER_INGRESS=y
+CONFIG_NETFILTER_NETLINK=y
+CONFIG_NETFILTER_FAMILY_BRIDGE=y
+CONFIG_NETFILTER_FAMILY_ARP=y
+CONFIG_NETFILTER_NETLINK_ACCT=y
+CONFIG_NETFILTER_NETLINK_QUEUE=y
+CONFIG_NETFILTER_NETLINK_LOG=y
+CONFIG_NETFILTER_NETLINK_OSF=y
+CONFIG_NETFILTER_CONNCOUNT=y
+CONFIG_NETFILTER_NETLINK_GLUE_CT=y
+CONFIG_NETFILTER_SYNPROXY=y
+CONFIG_NETFILTER_XTABLES=y
+CONFIG_NETFILTER_XT_MARK=y
+CONFIG_NETFILTER_XT_CONNMARK=y
+CONFIG_NETFILTER_XT_SET=y
+CONFIG_NETFILTER_XT_TARGET_AUDIT=y
+CONFIG_NETFILTER_XT_TARGET_CHECKSUM=y
+CONFIG_NETFILTER_XT_TARGET_CLASSIFY=y
+CONFIG_NETFILTER_XT_TARGET_CONNMARK=y
+CONFIG_NETFILTER_XT_TARGET_CONNSECMARK=y
+CONFIG_NETFILTER_XT_TARGET_CT=y
+CONFIG_NETFILTER_XT_TARGET_DSCP=y
+CONFIG_NETFILTER_XT_TARGET_HL=y
+CONFIG_NETFILTER_XT_TARGET_HMARK=y
+CONFIG_NETFILTER_XT_TARGET_IDLETIMER=y
+CONFIG_NETFILTER_XT_TARGET_LED=y
+CONFIG_NETFILTER_XT_TARGET_LOG=y
+CONFIG_NETFILTER_XT_TARGET_MARK=y
+CONFIG_NETFILTER_XT_NAT=y
+CONFIG_NETFILTER_XT_TARGET_NETMAP=y
+CONFIG_NETFILTER_XT_TARGET_NFLOG=y
+CONFIG_NETFILTER_XT_TARGET_NFQUEUE=y
+CONFIG_NETFILTER_XT_TARGET_NOTRACK=y
+CONFIG_NETFILTER_XT_TARGET_RATEEST=y
+CONFIG_NETFILTER_XT_TARGET_REDIRECT=y
+CONFIG_NETFILTER_XT_TARGET_TEE=y
+CONFIG_NETFILTER_XT_TARGET_TPROXY=y
+CONFIG_NETFILTER_XT_TARGET_TRACE=y
+CONFIG_NETFILTER_XT_TARGET_SECMARK=y
+CONFIG_NETFILTER_XT_TARGET_TCPMSS=y
+CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=y
+CONFIG_NETFILTER_XT_MATCH_ADDRTYPE=y
+CONFIG_NETFILTER_XT_MATCH_BPF=y
+CONFIG_NETFILTER_XT_MATCH_CGROUP=y
+CONFIG_NETFILTER_XT_MATCH_CLUSTER=y
+CONFIG_NETFILTER_XT_MATCH_COMMENT=y
+CONFIG_NETFILTER_XT_MATCH_CONNBYTES=y
+CONFIG_NETFILTER_XT_MATCH_CONNLABEL=y
+CONFIG_NETFILTER_XT_MATCH_CONNLIMIT=y
+CONFIG_NETFILTER_XT_MATCH_CONNMARK=y
+CONFIG_NETFILTER_XT_MATCH_CONNTRACK=y
+CONFIG_NETFILTER_XT_MATCH_CPU=y
+CONFIG_NETFILTER_XT_MATCH_DCCP=y
+CONFIG_NETFILTER_XT_MATCH_DEVGROUP=y
+CONFIG_NETFILTER_XT_MATCH_DSCP=y
+CONFIG_NETFILTER_XT_MATCH_ECN=y
+CONFIG_NETFILTER_XT_MATCH_ESP=y
+CONFIG_NETFILTER_XT_MATCH_HASHLIMIT=y
+CONFIG_NETFILTER_XT_MATCH_HELPER=y
+CONFIG_NETFILTER_XT_MATCH_HL=y
+CONFIG_NETFILTER_XT_MATCH_IPCOMP=y
+CONFIG_NETFILTER_XT_MATCH_IPRANGE=y
+CONFIG_NETFILTER_XT_MATCH_IPVS=y
+CONFIG_NETFILTER_XT_MATCH_L2TP=y
+CONFIG_NETFILTER_XT_MATCH_LENGTH=y
+CONFIG_NETFILTER_XT_MATCH_LIMIT=y
+CONFIG_NETFILTER_XT_MATCH_MAC=y
+CONFIG_NETFILTER_XT_MATCH_MARK=y
+CONFIG_NETFILTER_XT_MATCH_MULTIPORT=y
+CONFIG_NETFILTER_XT_MATCH_NFACCT=y
+CONFIG_NETFILTER_XT_MATCH_OSF=y
+CONFIG_NETFILTER_XT_MATCH_OWNER=y
+CONFIG_NETFILTER_XT_MATCH_POLICY=y
+CONFIG_NETFILTER_XT_MATCH_PHYSDEV=y
+CONFIG_NETFILTER_XT_MATCH_PKTTYPE=y
+CONFIG_NETFILTER_XT_MATCH_QUOTA=y
+CONFIG_NETFILTER_XT_MATCH_RATEEST=y
+CONFIG_NETFILTER_XT_MATCH_REALM=y
+CONFIG_NETFILTER_XT_MATCH_RECENT=y
+CONFIG_NETFILTER_XT_MATCH_SCTP=y
+CONFIG_NETFILTER_XT_MATCH_SOCKET=y
+CONFIG_NETFILTER_XT_MATCH_STATE=y
+CONFIG_NETFILTER_XT_MATCH_STATISTIC=y
+CONFIG_NETFILTER_XT_MATCH_STRING=y
+CONFIG_NETFILTER_XT_MATCH_TCPMSS=y
+CONFIG_NETFILTER_XT_MATCH_TIME=y
+CONFIG_NETFILTER_XT_MATCH_U32=y
+
+CONFIG_NF_NAT=y
+CONFIG_NF_NAT_NEEDED=y
+CONFIG_NF_TABLES=y
+CONFIG_NF_TABLES_SET=y
+CONFIG_NF_TABLES_INET=y
+CONFIG_NF_TABLES_NETDEV=y
+CONFIG_NF_DUP_NETDEV=y
+CONFIG_NF_FLOW_TABLE_INET=y
+CONFIG_NF_FLOW_TABLE=y
+CONFIG_NF_DEFRAG_IPV4=y
+CONFIG_NF_TABLES_IPV4=y
+CONFIG_NF_TABLES_ARP=y
+CONFIG_NF_FLOW_TABLE_IPV4=y
+CONFIG_NF_DUP_IPV4=y
+CONFIG_NF_REJECT_IPV4=y
+CONFIG_NF_NAT_IPV4=y
+CONFIG_NF_NAT_MASQUERADE_IPV4=y
+CONFIG_NF_TABLES_BRIDGE=y
+
+CONFIG_NF_CONNTRACK=y
+
+CONFIG_IP_NF_IPTABLES=y
+CONFIG_IP_NF_MATCH_AH=y
+CONFIG_IP_NF_MATCH_ECN=y
+CONFIG_IP_NF_MATCH_RPFILTER=y
+CONFIG_IP_NF_MATCH_TTL=y
+CONFIG_IP_NF_FILTER=y
+CONFIG_IP_NF_TARGET_REJECT=y
+CONFIG_IP_NF_TARGET_SYNPROXY=y
+CONFIG_IP_NF_NAT=y
+CONFIG_IP_NF_TARGET_MASQUERADE=y
+CONFIG_IP_NF_TARGET_NETMAP=y
+CONFIG_IP_NF_TARGET_REDIRECT=y
+CONFIG_IP_NF_MANGLE=y
+CONFIG_IP_NF_TARGET_CLUSTERIP=y
+CONFIG_IP_NF_TARGET_ECN=y
+CONFIG_IP_NF_TARGET_TTL=y
+CONFIG_IP_NF_RAW=y
+CONFIG_IP_NF_SECURITY=y
+CONFIG_IP_NF_ARPTABLES=y
+CONFIG_IP_NF_ARPFILTER=y
+CONFIG_IP_NF_ARP_MANGLE=y
+
+CONFIG_NFT_BRIDGE_REJECT=y
+
+CONFIG_BRIDGE_NETFILTER=y

rootf-kernel/kernel-config/virtio.config

@@ -0,0 +1,16 @@
+CONFIG_BLK_MQ_VIRTIO=y
+CONFIG_VIRTIO_BLK=y
+CONFIG_VIRTIO_BLK_SCSI=y
+CONFIG_SCSI_VIRTIO=y
+CONFIG_VIRTIO_NET=y
+CONFIG_VIRTIO_CONSOLE=y
+CONFIG_HW_RANDOM_VIRTIO=y
+CONFIG_VIRTIO=y
+CONFIG_VIRTIO_MENU=y
+CONFIG_VIRTIO_PCI=y
+CONFIG_VIRTIO_PCI_LEGACY=y
+CONFIG_VIRTIO_BALLOON=y
+CONFIG_VIRTIO_INPUT=y
+CONFIG_VIRTIO_MMIO=y
+CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y
+CONFIG_CRYPTO_DEV_VIRTIO=y

rootf-kernel/kernel.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+# inspired by https://github.com/oraoto/archlinux-firecracker/blob/master/scripts/build-arch-kernel.sh
+
+KERNEL_VERSION=5.11.2
+
+mkdir -p build
+
+cd build
+
+## Install build tools
+# pacman -Syu base-devel bc pahole --ignore linux-firmware
+
+## Get kernel source
+curl -o linux.tar.xz "https://mirrors.tuna.tsinghua.edu.cn/kernel/v5.x/linux-$KERNEL_VERSION.tar.xz"
+tar xf linux.tar.xz
+cd linux-$KERNEL_VERSION/
+
+## Get Archlinux kernel config
+curl -o .config https://git.archlinux.org/svntogit/packages.git/plain/trunk/config?h=packages/linux
+
+## Disable modules
+sed 's/\(.*\)=m/#\1 is not set/g' -i .config
+sed 's/\(.*\)MOUSE\(.*\)=y/\1MOUSE\2=n/g' -i .config
+sed 's/\(.*\)USB\(.*\)=y/\1USB\2=n/g' -i .config
+sed 's/\(.*\)TOUCHSCREEN\(.*\)=y/\1TOUCHSCREEN\2=n/g' -i .config
+sed 's/\(.*\)HID\(.*\)=y/\1HID\2=n/g' -i .config
+sed 's/\(.*\)GPU\(.*\)=y/\1GPU\2=n/g' -i .config
+sed 's/\(.*\)GPIO\(.*\)=y/\1GPIO\2=n/g' -i .config
+sed 's/\(.*\)NVDIMM\(.*\)=y/\1NVDIMM\2=n/g' -i .config
+sed 's/\(.*\)MFD\(.*\)=y/\1MFD\2=n/g' -i .config
+sed 's/\(.*\)XEN\(.*\)=y/\1XEN\2=n/g' -i .config
+sed 's/\(.*\)VIDEO\(.*\)=y/\1VIDEO\2=n/g' -i .config
+# sed 's/\(.*\)PCI\(.*\)=y/\1PCI\2=n/g' -i .config
+sed 's/\(.*\)WLAN\(.*\)=y/\1WLAN\2=n/g' -i .config
+sed 's/\(.*\)DRM\(.*\)=y/\1DRM\2=n/g' -i .config
+
+cat ../../config/virtio.config >> .config
+cat ../../config/fs.config >> .config
+cat ../../config/net.config >> .config
+
+## Add KVM guest support
+make kvm_guest.config
+
+make -j$(nproc)
+
+./scripts/extract-vmlinux ./arch/x86_64/boot/bzImage > ../../output/arch-vmlinux.bin

rootf-kernel/rootfs.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+# inspired by https://github.com/oraoto/archlinux-firecracker/blob/master/scripts/build-arch-rootfs.sh
+
+DISK_SIZE=4G
+DISK_FILE=../output/arch-rootfs.ext4
+DISK_ROOT=../output/mount
+
+cd $(dirname "${BASH_SOURCE[0]}")
+
+# Allocate rootfs disk
+fallocate -l 4G $DISK_FILE
+mkfs.ext4 $DISK_FILE
+
+# Mount rootfs to mount
+mkdir -p $DISK_ROOT
+
+sudo mount $DISK_FILE $DISK_ROOT
+
+yes y | sudo pacstrap -i -c $DISK_ROOT bash filesystem systemd-sysvcompat pacman iproute2
+
+echo "nameserver 1.1.1.1" | sudo tee $DISK_ROOT/etc/resolv.conf
+
+sudo tee $DISK_ROOT/etc/systemd/system/firecracker-network.service <<-'EOF'
+[Unit]
+Description=Firecracker Network
+
+[Service]
+Type=oneshot
+ExecStart=ip link set eth0 up
+ExecStart=ip addr add 172.16.0.2/24 dev eth0
+ExecStart=ip route add default via 172.16.0.1 dev eth0
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+sudo ln -s /etc/systemd/system/firecracker-network.service $DISK_ROOT/etc/systemd/system/multi-user.target.wants/
+
+# Remove default (locked) root password
+# See https://github.com/archlinux/svntogit-packages/commit/0320c909f3867d47576083e853543bab1705185b
+
+sudo sed 's/^root:.*/root::14871::::::/' -i $DISK_ROOT/etc/shadow
+
+sudo umount $DISK_ROOT
+rmdir $DISK_ROOT