Subversion Repositories amber

File in this directory:

initrd                      A disk image needed if you want to build the

                            Amber Linux kernel from sources

patch-2.4.27-amber2.bz2     Amber Linux patch file

patch-2.4.27-vrs1.bz2       ARM Linux patch file

README.txt                  This file

vmlinux                     Kernel executable file

vmlinux.dis.bz2             Kernel disassembly file, bzip2 compressed

vmlinux.mem.bz2             Kernel .mem file for Verilog simulations, bzip2 compressed

                            If you build the kernal from source these 2 files

                            get replaced.

# +++++++++++++++++++++++++++++++++++++++++++

# How to run Amber Linux kernel on a development board

# +++++++++++++++++++++++++++++++++++++++++++

1. Download the bitfile to configure the FPGA using Impact or Chipscope

2. Connect HyperTerminal to the serial port on the FPGA to connect to the boot loader

3. Download the disk image

> b 800000

Then select one of the provided disk image files to transfer, e.g.

   $AMBER_BASE/sw/vmlinux/initrd-200k-hello-world

4. Download the kernel image

> l

Then select the file $AMBER_BASE/sw/vmlinux/vmlinux to transfer

5. Execute the kernel

> j 80000

# +++++++++++++++++++++++++++++++++++++++++++

# How to build Amber Linux kernel from source

# +++++++++++++++++++++++++++++++++++++++++++

# If you also want to create your own initrd disk image,

# then follow that procedure (below) first.

# Set the location on your system where the Amber project is located

export AMBER_BASE=/proj/opencores-svn/trunk

# Pick a directory on your system where you want to build Linux

export LINUX_WORK_DIR=/proj/amber2-linux

export AMBER_CROSSTOOL=arm-none-linux-gnueabi

# Create the Linux build directory

test -e ${LINUX_WORK_DIR} || mkdir ${LINUX_WORK_DIR}

cd ${LINUX_WORK_DIR}

# Download the kernel source

wget http://www.kernel.org/pub/linux/kernel/v2.4/linux-2.4.27.tar.gz

tar zxf linux-2.4.27.tar.gz

ln -s linux-2.4.27 linux

cd linux

#Apply 2 patch files

cp ${AMBER_BASE}/sw/vmlinux/patch-2.4.27-vrs1.bz2 .

cp ${AMBER_BASE}/sw/vmlinux/patch-2.4.27-amber2.bz2 .

bzip2 -d patch-2.4.27-vrs1.bz2

bzip2 -d patch-2.4.27-amber2.bz2

patch -p1 < patch-2.4.27-vrs1

patch -p1 < patch-2.4.27-amber2

# Build the kernel and create a .mem file for simulations

make dep

make vmlinux

cp vmlinux vmlinux_unstripped

${AMBER_CROSSTOOL}-objcopy -R .comment -R .note vmlinux

${AMBER_CROSSTOOL}-objcopy --change-addresses -0x02000000 vmlinux

$AMBER_BASE/sw/tools/amber-elfsplitter vmlinux > vmlinux.mem

# Add the ram disk image to the .mem file

# You can use one of the provided disk images or generate your own (see below)

$AMBER_BASE/sw/tools/amber-bin2mem ${AMBER_BASE}/sw/vmlinux/initrd-200k-hello-world 800000 >> vmlinux.mem

${AMBER_CROSSTOOL}-objdump -C -S -EL vmlinux_unstripped > vmlinux.dis

cp vmlinux.mem $AMBER_BASE/sw/vmlinux/vmlinux.mem

cp vmlinux.dis $AMBER_BASE/sw/vmlinux/vmlinux.dis

# Run the Linux simulation to verify that you have a good kernel image

cd $AMBER_BASE/hw/sim

run vmlinux

# +++++++++++++++++++++++++++++++++++++++++++

# How to create your own initrd file

# +++++++++++++++++++++++++++++++++++++++++++

This file is the disk image that Linux mounts as

part of the boot process. It contains a bare bones Linux directory

structure and an init file (which is just hello-world renamed).

# Set the location on your system where the Amber project is located

export AMBER_BASE=/proj/opencores-svn/trunk

# Pick a directory on your system where you want to build Linux

export LINUX_WORK_DIR=/proj/amber2-linux

# Create the Linux build directory

test -e ${LINUX_WORK_DIR} || mkdir ${LINUX_WORK_DIR}

cd ${LINUX_WORK_DIR}

# Need root permissions to mount disks

su root

dd if=/dev/zero of=initrd bs=200k count=1

mke2fs -F -m0 -b 1024 initrd

mkdir mnt

mount -t ext2 -o loop initrd ${LINUX_WORK_DIR}/mnt

# Add files

mkdir ${LINUX_WORK_DIR}/mnt/sbin

mkdir ${LINUX_WORK_DIR}/mnt/dev

mkdir ${LINUX_WORK_DIR}/mnt/bin

mkdir ${LINUX_WORK_DIR}/mnt/etc

mkdir ${LINUX_WORK_DIR}/mnt/proc

mkdir ${LINUX_WORK_DIR}/mnt/lib

mknod ${LINUX_WORK_DIR}/mnt/dev/console c 5 1

mknod ${LINUX_WORK_DIR}/mnt/dev/tty2 c 4 2

mknod ${LINUX_WORK_DIR}/mnt/dev/null c 1 3

mknod ${LINUX_WORK_DIR}/mnt/dev/loop0 b 7 0

chmod 600 ${LINUX_WORK_DIR}/mnt/dev/*

cp $AMBER_BASE/sw/hello-world/hello-world.flt ${LINUX_WORK_DIR}/mnt/sbin/init

#cp $AMBER_BASE/sw/dhry/dhry.flt ${LINUX_WORK_DIR}/mnt/sbin/init

chmod +x ${LINUX_WORK_DIR}/mnt/sbin/init

# Check

df ${LINUX_WORK_DIR}/mnt

# Unmount

umount ${LINUX_WORK_DIR}/mnt

rm -rf ${LINUX_WORK_DIR}/mnt

exit # from being root

cp initrd $AMBER_BASE/sw/vmlinux/initrd-

---

If 200k is not large enough, you can change the size as follows.

You'll need to change a couple of values in the ATAG data structure defined in the

boot loader. Specifically the ATAG_RAMDISK_SIZE parameter and the ATAG_INITRD_SIZE

parameter in file $AMBER_BASE/sw/boot-loader/start.S. Then create an initrd image

with a different bs number, for example;

dd if=/dev/zero of=initrd bs=400k count=1

The initrd image size gets picked up automatically by the kernel, as long as the

ram disk defined in the ATAG data is large enough to contain it.