README.md

@@ -1,11 +1,11 @@
 # minimal-linux
 
-A minimal linux distro with busybox. Kernel loads up in Qemu but doesn't "init" into shell properly yet.
+A minimal linux distro cross compiled for ARM with busybox. This works fine but doing the exact same thing with x86_64 doesn't work in the main branch? Don't know whats happening but I presume the startup process is much more complicated for x86_64
 
 ## build from scratch
 
-Just do: `./build.sh`
+`./manual-linux.sh`
 
 ### test with QEMU
 
-`./start-vm.sh`
+`./start-qemu-terminal.sh`

manual-linux.sh

@@ -1,15 +1,16 @@
+#!/bin/bash
+# Script create the simplest linux distro ever
+
 set -e
 set -u
 
-OUTDIR=/minimal-linux
+OUTDIR=/tmp/aeld
 KERNEL_REPO=git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
 KERNEL_VERSION=v6.1.14
 BUSYBOX_VERSION=1_33_1
-
+# FINDER_APP_DIR=$(realpath $(dirname $0))
-#ARCH=arm64
+ARCH=arm64
-#CROSS_COMPILE=aarch64-none-linux-gnu-
+CROSS_COMPILE=aarch64-none-linux-gnu-
-ARCH=x86_64
-CROSS_COMPILE=
 
 if [ $# -lt 1 ]
 then
@@ -35,13 +36,26 @@ if [ ! -e ${OUTDIR}/linux-stable/arch/${ARCH}/boot/Image ]; then
     #make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE" menuconfig
     #make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE" config
     # use default config
-    make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE" defconfig
+    # make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE" defconfig
-    make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE"
+    # make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE"
+    # (deepclean) the kernal Biuld tree - remove any existing configuration
+	make ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} mrproper
+	# configure our virt device we simulate in qemu
+	echo "(configure our virt)"
+	make ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} defconfig
+	# biuld a kernel image for booting with qemu
+	echo "biuld a kernel image for booting with qemu"
+	make -j4 ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} all
+	# build any kernel modules
+	echo "build any kernel modules"
+	make ARCH=arm64 CROSS_COMPILE=${CROSS_COMPILE} modules
+	# build the device tree
+	make ARCH=arm64 CROSS_COMPILE=${CROSS_COMPILE} dtbs
 fi
 
 echo "Adding the Image in outdir"
 
-cp ${OUTDIR}/linux-stable/arch/x86/boot/bzImage ${OUTDIR}
+cp ${OUTDIR}/linux-stable/arch/${ARCH}/boot/Image ${OUTDIR}
 
 echo "Creating the staging directory for the root filesystem"
 cd "$OUTDIR"
@@ -96,18 +110,33 @@ ${CROSS_COMPILE}readelf -a ${OUTDIR}/rootfs/bin/busybox | grep "program interpre
 ${CROSS_COMPILE}readelf -a ${OUTDIR}/rootfs/bin/busybox | grep "Shared library"
 
 # TODO: Add library dependencies to rootfs
-SYSROOT=$(${CROSS_COMPILE}gcc -print-sysroot)
+CROSS_COMPILE_PATH=$(${CROSS_COMPILE}gcc --print-sysroot)
-echo "SYSROOT is : $SYSROOT"
+cp "${CROSS_COMPILE_PATH}"/lib/ld-linux-aarch64.so.1 "${OUTDIR}"/rootfs/lib
-cp -a ${SYSROOT}/lib64/ld-linux-x86-64.so.2 ${OUTDIR}/rootfs/lib
+cp "${CROSS_COMPILE_PATH}"/lib64/libm.so.6 "${OUTDIR}"/rootfs/lib64
-echo "cp 1 result $#"
+cp "${CROSS_COMPILE_PATH}"/lib64/libresolv.so.2 "${OUTDIR}"/rootfs/lib64
-cp -r ${SYSROOT}/lib64/ ${OUTDIR}/rootfs/lib64
+cp "${CROSS_COMPILE_PATH}"/lib64/libc.so.6 "${OUTDIR}"/rootfs/lib64
-echo "cp 2 result $#"
 
 # TODO: Make device nodes
-cd ${OUTDIR}/rootfs
+cd "$OUTDIR/rootfs"
 sudo mknod -m 666 dev/null c 1 3
 sudo mknod -m 600 dev/console c 5 1
-ls -l dev
+
+# TODO: Copy scripts and executables to a directory
+# on the target rootfs
+
+# embedded apps and ohter installs can go here?
+
+# cd "$FINDER_APP_DIR"
+# make clean
+# make ARCH="$ARCH" CROSS_COMPILE="$CROSS_COMPILE"
+
+# cp writer ${OUTDIR}/rootfs/home
+# cp finder.sh ${OUTDIR}/rootfs/home
+# cp finder-test.sh ${OUTDIR}/rootfs/home
+# cp writer.sh ${OUTDIR}/rootfs/home
+# mkdir ${OUTDIR}/rootfs/home/conf
+# cp -r conf/. ${OUTDIR}/rootfs/home/conf
+# cp autorun-qemu.sh ${OUTDIR}/rootfs/home
 
 # TODO: Chown the root directory
 cd "$OUTDIR/rootfs"
@@ -116,4 +145,4 @@ sudo chown -R root:root *
 # TODO: Create initramfs.cpio.gz
 find . | cpio -H newc -ov --owner root:root > ${OUTDIR}/initramfs.cpio
 cd "$OUTDIR"
-gzip -f initramfs.cpio
+gzip -f initramfs.cpio

start-qemu-terminal.sh

@@ -1,16 +1,17 @@
 # !/bin/bash
-# Script to test build using qemu x86 emulator.
+# Script to open qemu terminal.
+# Author: Siddhant Jajoo.
 
 set -e
 
 OUTDIR=$1
 
 if [ -z "${OUTDIR}" ]; then
-    OUTDIR=/minimal-linux
+    OUTDIR=/tmp/aeld
     echo "No outdir specified, using ${OUTDIR}"
 fi
 
-KERNEL_IMAGE=${OUTDIR}/linux-stable/arch/x86/boot/bzImage
+KERNEL_IMAGE=${OUTDIR}/Image
 INITRD_IMAGE=${OUTDIR}/initramfs.cpio.gz
 
 if [ ! -e ${KERNEL_IMAGE} ]; then
@@ -25,13 +26,7 @@ fi
 
 echo "Booting the kernel"
 # See trick at https://superuser.com/a/1412150 to route serial port output to file
-qemu-system-x86_64 \
+qemu-system-aarch64 -m 256M -M virt -cpu cortex-a53 -nographic -smp 1 -kernel ${KERNEL_IMAGE} \
-        -m 256M \
-        -M pc \
-        -cpu qemu64 \
-        -nographic \
-        -smp 1 \
-        -kernel ${KERNEL_IMAGE} \
         -chardev stdio,id=char0,mux=on,logfile=${OUTDIR}/serial.log,signal=off \
-        -serial chardev:char0 -mon chardev=char0 \
+        -serial chardev:char0 -mon chardev=char0\
-        -append "rdinit=/home/autorun-qemu.sh console=ttyAMA0" -initrd ${INITRD_IMAGE}
+        -append "rdinit=/bin/sh" -initrd ${INITRD_IMAGE}