I feel quite disappointed, and finally, I decided to buy my own hosting space to make sure that my code is archived better. Currently, I’m on my way to upload my backup into new site. Hopefully, I can find all of the code snippets that I posted in this blog in my DVD backup.

Anyway, I also want to thank you for visiting or subscribing Embedded Freak so far. I hope my blog will still be interested enough for you. If you’re looking for embedded freak’s new website, it’ll be hosted in http://embeddedfreak.materee.com

I’ll post the latest news of the server migration once it’s done.

Thank you

Disko provides simple tutorial to kickstart your Disko project. You can download it using git:

# git clone git://www.diskohq.org/disko-tutorials.git

Inside the ‘disko-tutorials’ directory, go to ‘firststeps’ directory, and cross compile it with:

# CXX=arm-none-linux-gnueabi-g++ CXXFLAGS=-mcpu=arm926ej-s \
  PKG_CONFIG_PATH=$HOST_DIR/lib/pkgconfig make

Now copy all of firststeps directory to your target directory (or to SD-Card), and copy all the library dependencies (as described in my last post, ‘Preparing Root Filesystem’ section). Then run it..(Don’t forget to change the diskorc.xml before running the program)

Here’s some pics and videos of the ‘Firststeps’ tutorial in PHY3250 board

Disko Firststeps Tutorial 01

Disko 'Firststeps' Tutorial 02

Disko 'Firststeps' Tutorial 04

I’m running this test based on PHYCORE-LPC3250 at 208Mhz. The bootloaders (NXP S1L along with uboot) and linux kernel installation is provided in lpclinux.com.

To update your PHYCORE-LPC3250 S1L (new S1L is provided to ease LPC3250 board porting and adding more features), see this page. You won’t mess around with kernel’s source code or the bootloader. Hence, it’s better to burn everything into NAND flash.To burn the U-Boot in PHYCORE-LPC3250′s  flash, see this page. To burn the Linux kernel into PHYCORE-LPC3250′s  flash, see this page.

My suggestion is to add NFS server in your PC host, because modifying the root filesystem while debugging the Disko application is quite a troublesome if you use SD-Card (see my last post for it). However, just to run this demo, you can download your root filesystem into SD-Card and deploy it in your board.

Ok, that’s enough for the small talk..now I’m going to talk big =P..kidding..

Preparing Disko

The first thing is compile the libraries and Disko framework (here).

The issue with Disko-1.7.0 is that the library keeps referring to $HOST_DIR, even though it has been copied to target board. I’m adding this patch to hardcode the target’s resource root directory.

--- disko-1.7.0/src/mmsinfo/mmsinfo.cpp	2010-04-27 22:22:16.000000000 +0800
+++ disko-fix-1.7.0/src/mmsinfo/mmsinfo.cpp	2010-11-26 16:18:17.958657687 +0800
@@ -33,5 +33,5 @@
 #include "mmsinfo/mmsinfo.h"
 const char *getPrefix() {
-	return DISKO_PREFIX;
+	return "";
 }

Save the patch as ‘disko-cross_target.patch’. Apply the patches in the disko’s build directory, then re-compile and install disko

# cd $BUILD_DIR/disko-1.7.0
# patch -p1 < disko-cross_target.patch
# CXX=arm-none-linux-gnueabi-g++ CXXFLAGS="-mcpu=arm926ej-s" \
	PKG_CONFIG_PATH=$HOST_DIR/lib/pkgconfig \
	scons graphics=fbdev prefix=$HOST_DIR cross=true install

Preparing Disko-Demos

See my previous post..

Preparing Root Filesystem

Basically, it’s the same steps as in previous post, but there’s some additional steps that’re needed to be added. First, download, compile, and install the busybox into $TARGET_DIR

# tar xvjf busybox-1.18.0.tar.bz2
# cd busybox-1.18.0
# CFLAGS="-mcpu=arm926ej-s" make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- menuconfig
.....add in the utilities that you need..I'm using the standard utilities..
# CFLAGS="-mcpu=arm926ej-s" make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi-
# CFLAGS="-mcpu=arm926ej-s" make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- CONFIG_PREFIX=$TARGET_DIR install

Then install the busybox’s library dependencies

# arm-none-linux-gnueabi-readelf -d busybox

Dynamic section at offset 0xdb0cc contains 25 entries:
  Tag        Type                         Name/Value
 0x00000001 (NEEDED)                     Shared library: [libm.so.6]
 0x00000001 (NEEDED)                     Shared library: [libc.so.6]
 0x0000000c (INIT)                       0xc0a0
 0x0000000d (FINI)                       0xbd5fc
 0x00000019 (INIT_ARRAY)                 0xeb0c0
 ...
# mkdir $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/libm.so.6 $TARGET_DIR/lib/
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/libc.so.6 $TARGET_DIR/lib/
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/ld-linux.so.3 $TARGET_DIR/lib/

After that, also install the ‘disko-demos’ library dependencies.

# arm-none-linux-gnueabi-readelf -d $TARGET_DIR/bin/demo

Dynamic section at offset 0x2d028 contains 37 entries:
  Tag        Type                         Name/Value
 0x00000001 (NEEDED)                     Shared library: [libdisko.so]
 0x00000001 (NEEDED)                     Shared library: [libxml2.so.2]
 0x00000001 (NEEDED)                     Shared library: [libsigc-2.0.so.0]
 0x00000001 (NEEDED)                     Shared library: [libpng14.so.14]
 0x00000001 (NEEDED)                     Shared library: [libfreetype.so.6]
 0x00000001 (NEEDED)                     Shared library: [libcurl.so.4]
 0x00000001 (NEEDED)                     Shared library: [libdl.so.2]
 0x00000001 (NEEDED)                     Shared library: [libsqlite3.so.0]
 0x00000001 (NEEDED)                     Shared library: [libstdc++.so.6]
 0x00000001 (NEEDED)                     Shared library: [libm.so.6]
 0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
 0x00000001 (NEEDED)                     Shared library: [libc.so.6]
 0x00000001 (NEEDED)                     Shared library: [libpthread.so.0]
 0x00000001 (NEEDED)                     Shared library: [librt.so.1]
 0x0000000c (INIT)                       0xea0c
 ................
# cp $HOST_DIR/lib/libdisko.so $TARGET_DIR/lib
# cp $HOST_DIR/lib/libxml2.so.2 $TARGET_DIR/lib
# cp $HOST_DIR/lib/libsigc-2.0.so.0 $TARGET_DIR/lib
# cp $HOST_DIR/lib/libpng14.so.14 $TARGET_DIR/lib
# cp $HOST_DIR/lib/libfreetype.so.6 $TARGET_DIR/lib
# cp $HOST_DIR/lib/libcurl.so.4 $TARGET_DIR/lib
# cp $HOST_DIR/lib/libsqlite3.so.0 $TARGET_DIR/lib
.....Not in the list, but libpng depends on it
# cp $HOST_DIR/lib/libz.so.1 $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/libdl.so.2 $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/libgcc_s.so.1 $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/libpthread.so.0 $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/lib/librt.so.1 $TARGET_DIR/lib
# cp $CODESOURCERY/arm-none-linux-gnueabi/libc/usr/lib/libstdc++.so.6 $TARGET_DIR/lib

Copy also the XML files for Disko GUI’s configuration

# cp -R $HOST_DIR/share/disko $TARGET_DIR/share

The next step is installing the device mount point, so that our applications can communicate with the device drivers.

# mkdir $TARGET_DIR/dev
...Minimum standard device files to run Linux
# sudo mknod $TARGET_DIR/dev/console c 5 1
# sudo mknod $TARGET_DIR/dev/null c 1 3
# sudo mknod $TARGET_DIR/dev/zero c 1 5
...Need device file for SD-Card partition #1, because the rootfs is stored there
# sudo mknod $TARGET_DIR/dev/mmcblk0p1 b 179 1
...Serial console for boot..
# sudo mknod $TARGET_DIR/dev/ttyS0 c 4 64
...Framebuffer...
# sudo mknod $TARGET_DIR/dev/fb0 c 29 0
...Touchscreen
# mkdir $TARGET_DIR/dev/input
# sudo mknod $TARGET_DIR/dev/input/event0 c 13 64
...Virtual terminals..needed by Disko
# sudo mknod $TARGET_DIR/dev/tty0 c 4 0
# sudo mknod $TARGET_DIR/dev/tty2 c 4 2

Then, prepare the Linux’s system init files

# vi $TARGET_DIR/etc/inittab
::sysinit:/etc/init.d/rcS
::askfirst:/bin/sh
# mkdir TARGET_DIR/etc/init.d
# vi $TARGET_DIR/etc/init.d/rcS
/bin/mount -t proc proc /proc
echo "Welcome to Disko-Demos for LPC3250"
# chmod +x $TARGET_DIR/etc/init.d/rcS
# mkdir $TARGET_DIR/proc

Phewww….that was long isn’t it ??

Configuring Disko

The disko config is stored in ‘$TARGET_DIR/etc/diskorc.xml’. To run it on PHYCORE-LPC3250, you need these changes:

<graphics>
    <parameter name="fullscreen" value="true"/>
    <!-- PHY3250 LCD is 240x320 @16bpp -->
    <parameter name="xres" value="240"/>
    <parameter name="yres" value="320"/>
    <parameter name="backend" value="fbdev" />
    <parameter name="outputtype" value="stdfb"/>
    <parameter name="videolayerid" value="0"/>
    <parameter name="videolayerpixelformat" value="RGB16" />
    .....
    <parameter name="graphicslayerid" value="0"/>
    <parameter name="graphicslayerpixelformat" value="RGB16"/>
    .....
    <parameter name="touchrect.w" value="240"/>
    <parameter name="touchrect.h" value="320"/>
    <parameter name="pointer" value="true"/>
    .....
    <parameter name="extendedaccel" value="false"/>
    <parameter name="allocmethod" value="malloc"/>
    <parameter name="hideapplication" value="false"/>
</graphics>

Running Disko-Demos

Well, that’s it..If you have NFS-based system, just enable the $TARGET_DIR as NFS exported directory, and access it from your PHY3250. If you use SD-Card, copy these files into your SD-Card, plug into PHY3250, and boot.
Once you boot, and reach the shell, run Disko-Demos with:

# ./bin/demo&

First download the ‘disko-demos’ application from disko’s GIT repository:

# git clone git://git.diskohq.com/disko-demos.git

Then create this Makefile to make your cross-compiling lifestyle easier (otherwise, there’ll be too much things to type)

# The top directory that contains all of the cross-libraries and tools
TOP_DIR    = $(HOME)/workspace/vicdist
# The directory that contains cross-libraries
HOST_DIR   = $(TOP_DIR)/host
# The installation directory..to be deployed in rootfs
TARGET_DIR = $(TOP_DIR)/target

CROSS_COMPILE ?= $(HOME)/workspace/codesourcery/bin/arm-none-linux-gnueabi-
CXX            = $(CROSS_COMPILE)g++
CXXFLAGS       = -mcpu=arm926ej-s
SCONS          = $(TOP_DIR)/bin/scons

disko-demos:
	CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) PKG_CONFIG_PATH=$(HOST_DIR)/lib/pkgconfig \
	LDFLAGS="-Wl,-rpath-link=$(HOST_DIR)/lib" \
	$(SCONS) prefix=$(TARGET_DIR) install

clean:
	CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) PKG_CONFIG_PATH=$(HOST_DIR)/lib/pkgconfig \
	LDFLAGS="-static -Wl,-rpath-link=$(HOST_DIR)/lib" \
	$(SCONS) -c

The ‘LDFLAGS=-Wl,-rpath=link=$(HOST_DIR)/lib’ is needed to tell the linker where it can find the dynamic libraries that disko framework depends on.

Then you can compile with

# make

The result is installed in $TARGET_DIR. The ‘Disko-Demos’ is installed in $TARGET_DIR/bin/demo. Let’s see what’s the dynamic libraries that it depends:

# arm-none-linux-gnueabi-readelf -d bin/demo |more

Dynamic section at offset 0x2d028 contains 37 entries:
  Tag        Type                         Name/Value
 0x00000001 (NEEDED)                     Shared library: [libdisko.so]
 0x00000001 (NEEDED)                     Shared library: [libxml2.so.2]
 0x00000001 (NEEDED)                     Shared library: [libsigc-2.0.so.0]
 0x00000001 (NEEDED)                     Shared library: [libpng14.so.14]
 0x00000001 (NEEDED)                     Shared library: [libfreetype.so.6]
 0x00000001 (NEEDED)                     Shared library: [libcurl.so.4]
 0x00000001 (NEEDED)                     Shared library: [libdl.so.2]
 0x00000001 (NEEDED)                     Shared library: [libsqlite3.so.0]
 0x00000001 (NEEDED)                     Shared library: [libstdc++.so.6]
 0x00000001 (NEEDED)                     Shared library: [libm.so.6]
 0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
 0x00000001 (NEEDED)                     Shared library: [libc.so.6]
 0x00000001 (NEEDED)                     Shared library: [libpthread.so.0]
 0x00000001 (NEEDED)                     Shared library: [librt.so.1]
 0x0000000c (INIT)                       0xea0c
 0x0000000d (FINI)                       0x2ef2c
 .......

Ok..So now we can copy the ‘bin/demo’ into rootfs, and copy the dependency shared-libraries into rootfs/lib directory.

Now…let’s hope that it works…**crossing fingers**

OpenSSL uses different configuration script (not the standard autoconf script..), and run by Perl. After working almost one night non-stop, I finally figure out how to configure OpenSSL-1.0.0b for cross compilation

# tar xvjf openssl-1.0.0b.tar.gz

# cd openssl-1.0.0b

# ./Configure --prefix=$(HOST_DIR) zlib-dynamic "linux-arm926ej-s":"arm-none-linux-gnueabi-gcc:-DTERMIO -O3 -Wall -I../../host/include::-D_REENTRANT::-L../../host/lib -ldl:BN_LLONG RC4_CHAR RC4_CHUNK DES_INT DES_UNROLL BF_PTR::bn_asm.o armv4-mont.o::aes_cbc.o aes-armv4.o:::sha1-armv4-large.o sha256-armv4.o sha512-armv4.o:::::::void:dlfcn:linux-shared:-fPIC::.so.1.0.0":arm-none-linux-gnueabi-ranlib::

# make

# make install

No sed, no awk, no regex to change the Configure script. Just change the $CC according to your cross-compiler-gcc and $CROSS_RANLIB with your cross-compiler-ranlib. The $(HOST_DIR)/include and $(HOST_DIR)/lib must have ARM’s zlib library and header files.

Now I need to update my Disko cross compile Makefile script..

But after working with few of LPCxxxx series, I finally can get a good view of how the Timer works. Here’s a block diagram of how the Timer works (at least in LPC23xx, LPC24xx, LPC31xx, LPC32xx, LPC111x, LPC176x)

LPCxxxx Timer Diagram

Note how each registers (CCR, CRx, MATx, MCR, etc) are matched to the block diagram functions.

In new LPCxxxx MCUs, the PWM (single edged PWM) is mux-ed with EMR functions. Hence, NXP added PWMC register to control which block (PWM or EMR) that controls the MATx pins.

LPCxxxx PWMC Register

So, how does the PWM block differs from EMR block ? Well, in PWM block, when TC = 0, the MATx pin will always toggled to LOW (VSS). In EMR block, it’s not.

Here’s some illustration of PWM using EMR:

LPCxxxx PWM with EMR block

Here’s illustration of PWM using PWM block:

LPCxxxx PWM with PWM block

Disko is an LGPL-licensed user interface (UI) application framework for the fast and simple development of flexible applications on Embedded Linux systems – with a particular focus on interactive user interfaces. It is high-performance and easy to learn, and due to its architecture is well suited to creating complex applications. Disko is a product of BerLinux Solutions GmbH.

Their website can be found here. It seems like it’s a nice GUI framework for embedded device. I’ve been trying to cross compile GTK-directFB without any luck, but Disko, along with its dependencies are very easy to be cross compiled.

To cross compile Disko, along with its dependencies, I’ve made a Makefile (to automate the compilation). Here’s the Disko cross-compile Makefile

# Disko package cross-compile for ARM926EJ-S
# ver 20101203_1050
#
# You will need extra tools (other than cross-toolchain) in your PC to run this Makefile:
# - pkg-config
# - pyhton
# - perl
# - SCons

TOP_DIR    = $(shell pwd)
BUILD_DIR  = $(TOP_DIR)/build
SOURCE_DIR = $(TOP_DIR)/source
HOST_DIR   = $(TOP_DIR)/host

KERNEL_HEADER   = $(HOST_DIR)/include

CURL_PACKAGE    = curl-7.21.1.tar.gz
DISKO_PACKAGE   = disko_1.7.0.tar.gz
FREETYPE_PACKAGE= freetype-2.4.3.tar.gz
OPENSSL_PACKAGE = openssl-1.0.0b.tar.gz
LIBSIGC_PACKAGE = libsigc++-2.2.8.tar.gz
LIBPNG_PACKAGE  = libpng-1.4.4.tar.gz
LIBXML2_PACKAGE = libxml2-sources-2.7.8.tar.gz
SQLITE_PACKAGE  = sqlite-amalgamation-3.7.3.tar.gz
ZLIB_PACKAGE    = zlib-1.2.5.tar.gz

CROSS_COMPILE ?= $(HOME)/workspace/codesourcery/bin/arm-none-linux-gnueabi-
AR             = $(CROSS_COMPILE)ar
CC             = $(CROSS_COMPILE)gcc
CXX            = $(CROSS_COMPILE)g++
LD             = $(CROSS_COMPILE)g++
NM             = $(CROSS_COMPILE)nm
RANLIB         = $(CROSS_COMPILE)ranlib
CFLAGS         = -mcpu=arm926ej-s
CXXFLAGS       = -mcpu=arm926ej-s
TAR            = /bin/tar
SCONS          = $(TOP_DIR)/bin/scons

all: freetype libsigc sqlite zlib openssl curl libpng libxml2 disko

# libcurl depends on zlib and openssl
curl:
	$(TAR) xvzf $(SOURCE_DIR)/$(CURL_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(CURL_PACKAGE))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	PKG_CONFIG_PATH=$(HOST_DIR)/lib/pkgconfig \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi \
	--disable-http --disable-ftp --disable-file --disable-ldap --disable-rtsp \
	--disable-proxy --disable-dict --disable-telnet --disable-tftp --disable-pop3 \
	--disable-imap --disable-smtp --disable-sspi --disable-crypto-auth --disable-cookies \
	--without-ldap-lib --without-lber-lib --without-krb4 --without-spnego \
	--without-gssapi --with-ssl --with-zlib=$(HOST_DIR) \
	--without-gnutls --without-polarssl --without-nss --without-ca-bundle \
	--without-libssh2 --without-librtmp --without-libidn && \
	$(MAKE) && \
	$(MAKE) install

# disko depends libcurl, freetype, libpng, libsigc, libxml2, sqlite
disko:
	$(TAR) xvzf $(SOURCE_DIR)/$(DISKO_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(subst _,-,$(firstword $(subst .tar., ,$(DISKO_PACKAGE)))) && \
	CXX=$(CXX) CXXFLAGS="$(CXXFLAGS) -I$(KERNEL_HEADER)" \
	PKG_CONFIG_PATH=$(HOST_DIR)/lib/pkgconfig \
	$(SCONS) graphics=fbdev prefix=$(HOST_DIR) cross=true install

freetype:
	$(TAR) xvzf $(SOURCE_DIR)/$(FREETYPE_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(FREETYPE_PACKAGE))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi && \
	$(MAKE) && \
	$(MAKE) install

# OpenSSL depends on zlib
openssl:
	$(TAR) xvzf $(SOURCE_DIR)/$(OPENSSL_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(OPENSSL_PACKAGE))) && \
	AR=$(AR) NM=$(NM) \
	./Configure --prefix=$(HOST_DIR) zlib-dynamic "linux-arm926ej-s":"$(CC):$(CFLAGS) -DTERMIO -O3 -Wall -I$(HOST_DIR)/include::-D_REENTRANT::-L$(HOST_DIR)/lib -ldl:BN_LLONG RC4_CHAR RC4_CHUNK DES_INT DES_UNROLL BF_PTR::bn_asm.o armv4-mont.o::aes_cbc.o aes-armv4.o:::sha1-armv4-large.o sha256-armv4.o sha512-armv4.o:::::::void:dlfcn:linux-shared:-fPIC::.so.1.0.0":$(RANLIB):: && \
	$(MAKE) && \
	$(MAKE) install

# libpng depends on zlib
libpng:
	$(TAR) xvzf $(SOURCE_DIR)/$(LIBPNG_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(LIBPNG_PACKAGE))) && \
	CC=$(CC) CFLAGS="$(CFLAGS) -I$(HOST_DIR)/include" \
	CPPFLAGS="-I$(HOST_DIR)/include" \
	LDFLAGS="-L$(HOST_DIR)/lib" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi && \
	$(MAKE) && \
	$(MAKE) install

libsigc:
	$(TAR) xvzf $(SOURCE_DIR)/$(LIBSIGC_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(LIBSIGC_PACKAGE))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	CXX=$(CXX) CXXFLAGS="$(CXXFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi && \
	$(MAKE) && \
	$(MAKE) install

#libxml2 depends on zlib
libxml2:
	$(TAR) xvzf $(SOURCE_DIR)/$(LIBXML2_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(subst -sources,,$(firstword $(subst .tar., ,$(LIBXML2_PACKAGE)))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi \
	--without-python --without-readline --with-zlib=$(HOST_DIR) && \
	$(MAKE) && \
	$(MAKE) install

sqlite:
	$(TAR) xvzf $(SOURCE_DIR)/$(SQLITE_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(subst -amalgamation,,$(firstword $(subst .tar., ,$(SQLITE_PACKAGE)))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	CXX=$(CXX) CXXFLAGS="$(CXXFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) --with-gnu-ld --host=arm-none-linux-gnueabi && \
	$(MAKE) && \
	$(MAKE) install

zlib:
	$(TAR) xvzf $(SOURCE_DIR)/$(ZLIB_PACKAGE) -C $(BUILD_DIR)
	cd $(BUILD_DIR)/$(firstword $(subst .tar., ,$(ZLIB_PACKAGE))) && \
	CC=$(CC) CFLAGS="$(CFLAGS)" \
	AR=$(AR) RANLIB=$(RANLIB) \
	./configure --prefix=$(HOST_DIR) && \
	$(MAKE) && \
	$(MAKE) install

To use the Makefile, first, install your target board’s kernel header in the $HOST_DIR. This is example for PHY3250 board.

# make ARCH=arm CROSS_COMPILE=$HOME/workspace/codesourcery/bin/arm-none-eabi- \
    INSTALL_HDR_PATH=$HOST_DIR phy3250_defconfig
# make ARCH=arm CROSS_COMPILE=$HOME/workspace/codesourcery/bin/arm-none-eabi- \
    INSTALL_HDR_PATH=$HOST_DIR headers_install

Now, if you are unlucky with the kernel, it may complains about redefinition of getline() (See the description and patch here). Hence, you need to patch it with this:

diff --git a/scripts/unifdef.c b/scripts/unifdef.c
index 552025e..977e682 100644
--- a/scripts/unifdef.c
+++ b/scripts/unifdef.c
@@ -206,7 +206,7 @@ static void             done(void);
 static void             error(const char *);
 static int              findsym(const char *);
 static void             flushline(bool);
-static Linetype         getline(void);
+static Linetype         parseline(void);
 static Linetype         ifeval(const char **);
 static void             ignoreoff(void);
 static void             ignoreon(void);
@@ -512,7 +512,7 @@ process(void)

        for (;;) {
                linenum++;
-               lineval = getline();
+               lineval = parseline();
                trans_table[ifstate[depth]][lineval]();
                debug("process %s -> %s depth %d",
                    linetype_name[lineval],
@@ -526,7 +526,7 @@ process(void)
  * help from skipcomment().
  */
 static Linetype
-getline(void)
+parseline(void)
 {
        const char *cp;
        int cursym;

Save the patch as getline.patch, and patch the kernel, before running the headers_install.

# patch -p1 < getline.patch
# make ARCH=arm CROSS_COMPILE=$HOME/workspace/codesourcery/bin/arm-none-eabi- \
    INSTALL_HDR_PATH=$HOST_DIR phy3250_defconfig
# make ARCH=arm CROSS_COMPILE=$HOME/workspace/codesourcery/bin/arm-none-eabi- \
    INSTALL_HDR_PATH=$HOST_DIR headers_install

Then, build the directory structures, and put the Makefile in the top directory

# mkdir convick convict/host convict/source convict/build
# vi convick/Makefile
---->insert the Makefile above

Then download the source code files into ‘source’ directory:

• curl-7.21.1.tar.gz
• disko_1.7.0.tar.gz
• freetype-2.4.3.tar.gz
• openssl-1.0.0b.tar.gz
• libsigc++-2.2.8.tar.gz
• libpng-1.4.4.tar.gz
• libxml2-sources-2.7.8.tar.gz
• sqlite-amalgamation-3.7.3.tar.gz
• zlib-1.2.5.tar.gz

Then just type ‘make’ to compile everything

# make -C convict

The header files and libraries will be put into ‘convict/host’ directory. Note that the Disko will be based on kernel’s framebuffer (make sure your kernel supports framebuffer device as well). Also, the libcurl is, well, almost non-functional since I don’t need network capability for my project.

The next step is combine it with the bootloader, kernel, and busybox to create most simplest GUI-based embedded linux that’s available.

Will keep this post updated till then.

Here’s the first challenge: the ARM Cortex-M0 interrupt vector table is not relocate-able. Hence, if we put our bootloader into ARM Cortex-M0, we need to find some way to chain the bootloader’s interrupt vector to user’s interrupt vector.

Here’s how I did it:

First of all, point all the interrupt vectors into single default handler, except for the Reset handler and MSP, which will always point to bootloader’s Reset handler and MSP. The reason is that all of the interrupts in bootloader, except for the Reset Handler, only needs to do one thing: fetch the user’s interrupt handler address and jump to that address.

#define ALIAS(f) __attribute__ ((alias (#f)))

extern void _vStackTop(void);
extern void ResetISR(void);
static void NMI_Handler(void) ALIAS(NormalIntDefaultHandler);
static void HardFault_Handler(void) ALIAS(NormalIntDefaultHandler);
static void SVCall_Handler(void) ALIAS(NormalIntDefaultHandler);
static void PendSV_Handler(void) ALIAS(NormalIntDefaultHandler);
static void SysTick_Handler(void) ALIAS(NormalIntDefaultHandler);
static void CAN_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void SSP1_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void I2C_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void TIMER16_0_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void TIMER16_1_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void TIMER32_0_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void TIMER32_1_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void SSP0_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void UART_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void ADC_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void WDT_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void BOD_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void PIOINT3_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void PIOINT2_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void PIOINT1_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void PIOINT0_IRQHandler(void) ALIAS(NormalIntDefaultHandler);
static void WAKEUP_IRQHandler(void) ALIAS(NormalIntDefaultHandler);

Then, define the ‘default interrupt handler’ as ‘naked’ (without function prolog), to save the stack and cpu cycle when handling interrupt.

static void NormalIntDefaultHandler(void) __attribute__((naked));

Inside the ‘default interrupt handler’, get the interrupt vector no, and its address offset in interrupt vector table. Then jump to user’s interrupt vector table offset. Some warning here is that, we need to make sure that the compiler will only use: r0-r3 and r12. The reason is that those registers are used for scratch registers (and it’s saved into stack automatically during start of interrupt by NVIC). Hence, it’s save for us to operate using the registers.

void NormalIntDefaultHandler(void) {
	/* Note: Only use scratch registers: r0, r1, r2, r3
	 */
	register void *user_program_offset asm("r2") = (void *) USER_PROGRAM_OFFSET;

	asm (
			".syntax unified    \n\t"
			/* Get current IRQ no from PSR */
			"MRS    r0, PSR     \n\t"
			/* Mask the interrupt number only */
			"MOVS   r1, #0x3F   \n\t"
			"ANDS   r0, r1      \n\t"
			/* Irq address position = IRQ No * 4 */
			"LSLS   r0, r0, #2  \n\t"
			/* Fetch the user vector offset */
			"LDR    r0, [r0, r2]\n\t"
			/* Jump to user interrupt vector */
			"BX     r0          \n\t"
			: /* output */
			: /* input */
			: /* clobbered reg */"r0","r1","r2"
	);

}

The “.syntax unified” instruction is needed to enable Thumb-2 specific instruction set.

Ok..I guess we can tail chain the ARM Cortex-M0 interrupts now..

diff -Naur ethernut-4.9.9/nut/Makevars.arm-gcc ethernut-nutconf_bug-4.9.9/nut/Makevars.arm-gcc
--- ethernut-4.9.9/nut/Makevars.arm-gcc	2009-08-13 23:31:41.000000000 +0800
+++ ethernut-nutconf_bug-4.9.9/nut/Makevars.arm-gcc	2010-09-28 18:07:14.788549190 +0800
@@ -39,7 +39,7 @@
 include $(top_srcdir)/Makevars.gcc

 # Set target specific variables.
-TRGT       = arm-elf-
+TRGT       = $(HOME)/workspace/codesourcery/bin/arm-none-eabi-
 MCFLAGS    = -mcpu=$(MCU)
 CFLAGS_MCU = $(MCFLAGS) -mthumb-interwork
 CXXFLAGS_MCU = $(CFLAGS_MCU)

diff -Naur ethernut-4.9.9/nut/os/osdebug.c ethernut-nutconf_bug-4.9.9/nut/os/osdebug.c
--- ethernut-4.9.9/nut/os/osdebug.c	2010-04-15 01:59:11.000000000 +0800
+++ ethernut-nutconf_bug-4.9.9/nut/os/osdebug.c	2010-09-28 18:22:36.868665145 +0800
@@ -116,7 +116,7 @@
 void NutDumpThreadQueue(FILE * stream, NUTTHREADINFO * tdp)
 {
 #ifdef ARCH_32BIT
-    static prog_char fmt[] = "%08lX %-8s %4u %s %08lX %08lX %08lX %9lu %s\n";
+    static prog_char fmt[] = "%08X %-8s %4u %s %08X %08X %08X %9u %s\n";
 #else
     static prog_char fmt[] = "%04X %-8s %4u %s %04X %04X %04X %5u %s\n";
 #endif
@@ -156,8 +156,8 @@
 {

 #ifdef ARCH_32BIT
-    static prog_char fmt1[] = "%08lX %-8s %4u %s %08lX %08lX %08lX %9lu %s";
-    static prog_char fmt2[] = " %08lX";
+    static prog_char fmt1[] = "%08X %-8s %4u %s %08X %08X %08X %9u %s";
+    static prog_char fmt2[] = " %08X";
 #else
     static prog_char fmt1[] = "%04X %-8s %4u %s %04X %04X %04X %5u %s";
     static prog_char fmt2[] = " %04X";
@@ -209,9 +209,9 @@
     static prog_char tname[] = "NutEventTimeout";
 #ifdef ARCH_32BIT
     static prog_char theader[] = "Address  Ticks  Left Callback\n";
-    static prog_char fmt1[] = "%08lX%6lu%6lu ";
+    static prog_char fmt1[] = "%08X%6lu%6lu ";
     static prog_char fmt2[] = "%09lX";
-    static prog_char fmt3[] = "(%08lX)\n";
+    static prog_char fmt3[] = "(%08X)\n";
 #else
     static prog_char theader[] = "Addr Ticks  Left Callback\n";
     static prog_char fmt1[] = "%04X%6lu%6lu ";
@@ -263,9 +263,9 @@
 {

 #ifdef ARCH_32BIT
-    static prog_char fmt1[] = "%08lx %9ld\n";
-    static prog_char fmt2[] = "%lu counted, but %lu reported\n";
-    static prog_char fmt3[] = "%lu bytes free\n";
+    static prog_char fmt1[] = "%08x %9d\n";
+    static prog_char fmt2[] = "%u counted, but %u reported\n";
+    static prog_char fmt3[] = "%u bytes free\n";
 #else
     static prog_char fmt1[] = "%04x %5d\n";
     static prog_char fmt2[] = "%u counted, but %u reported\n";

diff -Naur ethernut-4.9.9/nut/tools/nutconf/nutconfdoc.cpp ethernut-nutconf_bug-4.9.9/nut/tools/nutconf/nutconfdoc.cpp
--- ethernut-4.9.9/nut/tools/nutconf/nutconfdoc.cpp	2010-04-15 01:54:55.000000000 +0800
+++ ethernut-nutconf_bug-4.9.9/nut/tools/nutconf/nutconfdoc.cpp	2010-09-28 17:54:22.056471424 +0800
@@ -280,9 +280,11 @@
                     }
                 }
                 if (value) {
-					wxString escapedValue( value );
-					escapedValue.Replace(wxT("\""), wxT("\\\"")); // escape (") to (\");
-                    fprintf(fp, "%s = \"%s\"\n", opts->nco_name, escapedValue.c_str());
+                    wxString escapedValue = wxString::FromAscii( value );
+                    escapedValue.Replace(wxT("\""), wxT("\\\"")); // escape (") to (\");
+                    //fprintf(fp, "%s = \"%s\"\n", opts->nco_name, escapedValue.c_str());
+                    fprintf(fp, "%s = \"%s\"\n", opts->nco_name, (const char*) escapedValue.mb_str(wxConvUTF8));
+
                     free(value);
                 }
             }