1. Duke Cho EmbeddedWeb Co., Ltd.
2nd Open Seminar
uClinux on ARM7TDMI
Duke Cho
EmbeddedWeb Co., Ltd.

2. Table of Contents uClinux 소개 uClinux 개발환경 (for ARM7TDMI) DYAUS 보드 소개데모

3. uClinux History What is uClinux? Microcontroller Project (uCsimm)
uClinux Ports
RT-Kernel
Difference between Linux and uClinux

4. History
Jan 1998
The first ports of Linux to systems without a MMU was done by Kenneth Albanowski and D. Jeff Dionne
Dec 1998
D. Jeff Dionne and Michael Durrant started work on designing a simm module capability of using the uClinux code as an OS
Feb 1999
uClinux was successfully ported to the Motorola MCF5206 and MCF5307 ColdFire® microprocessor

5. History (cont’) 13 Sep 1999 22 Oct 1999 12 Apr 2000 16 Oct 2002
Jeff and Michael have released uClinux
22 Oct 1999
The uCsimm module Rt-Control Inc. created to run uClinux for embedded systems is now shipping
12 Apr 2000
New uClinux version pre7 announced
16 Oct 2002
the lastest uClinux version uc0 announced

6. What is uClinux?
A derivative of Linux 2.0 kernel intended for microcontro -llers without MMUs
Pronounced "you-see-linux“
Free software under GNU Public License

7. What is uClinux? (cont’)
Linux vs. uClinux
Multitasking can be tricky!!
Most of binaries and source code for the kernel have been rewritten to tighten-up and slim-down the code base
The uClinux is much, much smaller than the original Linux 2.0 kernel, while retaining the main advantages of the Linux OS: stability, superior network capability(a full TCP/IP stack), and excellent file system support (Only NFS, ext2, MS-DOS and FAT16/32)
common Linux API
uCKernel < 512 KB
uCKernel + tools < 900 KB

8. Microcontroller Project
The uCsimm module is a microcontroller module built specifically for the uClinux OS
developed by Arcturus Networks Inc.(formerly Rt-Control Inc.)
Features:
a 16 MHz 68EZ328 DragonBall microcontoller
2 MB Flash ROM
8 MB DRAM
21 general purpose I/O pins (or up to 13 with a graphic LCD panel enabled)
a built-in display driver, capable of driving a monochrome LCD panel up to QVGA resolution (640x480)
RS-232 Serial Support
High speed (1Mbps) I2C or SPI 3 wire serial
a 3.3 Volt draw

9. uClinux Ports
Community members from all over the world have been porting uClinux since its release in 1998
While originally developed for the Motorola chip, the number of available ports is always expanding
Ported Microcontrollers and Microprocessors
Motorola DragonBall, and other 68K Derivatives
Motorola ColdFire
ARM7TDMI and MC68EN302
ETRAX
Intel i960
PRISMA
Atari 68K
Several Devices running uClinux

10. uClinux Ports (cont’) Motorola DragonBall, and other 68K Derivatives
The first release to the public domain supporting the Motorola DragonBall(M68EZ328), M68238, and M68EN322
Since then, uClinux has grown exponentially, as the worlds greatest MMU-less chip receive there own ports
ARM7TDMI
Aplio ported APLIO/TRIO chip (ARM7TDMI) and MC68EN302
Built by standard uClinux kernel
Applied ARM patches and uClinux patches

11. Real-Time Extension for uClinux
uClinux Real Time moves up to 1pre1 (Oct., 2000)
Phil Wilshire has taken Kwonsk’s uClinux/RTL patches up to a later revision of uClinux
This has run on a uCSimm but is NOT fully tested yet
The Real Time Linux Portal

12. Differences between Linux and uClinux
Memory Management
The most significant difference is the lack of a MMU in uClinux
uClinux removes the MMU requirement by implementing a flat memory model (a 1-to-1 virtual-to-physical mapping)
uClinux allocates stack space at the end of the data for the executable
On uClinux, memory is limited to whatever physical memory is available at a given time to a program

13. Differences between Linux and … (cont’)
Linux Memory Map
Linux w/ Virtual Memory
stack
heap
static Data
text
TOP ADDR D (virtual)
Virtual Gap ~ 256 MB
Gaps Round to Next page
BASE ADDR C (virtual)
uClinux
stack
heap
static Data
text
TOP ADDR 00EA-6000 (physical)
BASE ADDR 00E (physical)
Heap Pages Allocated Using MMAP
Fixed size Stack
No Gaps

14. Differences between Linux and … (cont’)
Process Forking
Currently, the fork has not yet been implemented for any current implementation of uClinux
The use of vfork call or utilization of multiple threads instead of multiple processes can compensate for the lack of a working fork call in most cases
As uClinux cannot implement the copy on write policy of Linux, user applications must be careful not to change the state of data in memory between vfork and exec calls

15. uClinux 개발환경 Cross Development Tools Libraries
Debug Concept / JTAG Emulators / Debugger
Initialize Debgger / Intialization Script

16. EmbeddedICE macrocell Target System with NET+40
uClinux 개발환경
ARM
Core
EmbeddedICE macrocell
NET+40
Target System with NET+40
ROM
RAM
Peripheral
EmbeddedICE Interface
Debug Host
TAP Controller
The NET+40 is one of the ARM core SoC, manufactured by NetSilicon Inc.

17. uClinux 개발환경 (cont’) Cross Development Tools
binutils-2.11
gcc
gdb-5.0
elf2flt
binutils-2.10
elf2flt
genromfs-0.5.1

18. uClinux 개발환경 (cont’) Libraries uClibc uC-libc
The latest version: uClibc
download:
uC-libc
The old uClibc version
download:

19. uClinux 개발환경 (cont’) uClinux/distribution (Official Full Source)
The Latest snapshot source package is released on Sep. 27th, 2002
Support Architectures
M68k
ColdFire
ARM
Sparc
i960
NEC v850
OPENcores OR1000
Kernels
and kernel sources
Libraries
the older uC-libc and newer uClibc
Rich Application Sources

20. miscellaneous documents configuration files for buid
uClinux 개발환경 (cont’)
uClinux/distribution (Official Full Source)
uClinux-dist
Documentation
miscellaneous documents
bin
NETtel binary files
config
configuration files for buid
lib
the older uC-libc
linux-2.0.x
uClinux
linux-2.4.x
uClinux
tools
tools for romfs
romfs
root file system
uClibc
the newer uClibc
user
application programs
vendors
vendor products
/Arcturus
for uCdimm and uCsimm
/NetSilicon
for NET+40
/Samsung
for S3C4510

21. uClinux 개발환경 (cont’) Debug Concept
ARM7TDMI contains hardware extensions for advanced debugging features
The ARM7TDMI debug interface is based on IEEE Std , “Standard Test Access Port and Boundary-Scan Architecture”
The debug extensions allow the core to be stopped either on a given instruction fetch  breakpoint / watchpoint

22. uClinux 개발환경 (cont’) JEENI (JTAG EmbeddedICE EtherNet Interface)
Non-intrusive, uses no target resources & requires no porting to the target system
ROMless booting
Supports ARM7 and ARM9 cores containing "DI" macrocells
Unlimited software breakpoints
Ethernet and serial I/O ports for fast, flexible host interface
High-speed download (>100k bytes per second) of application code
Network compatibility allows shared and remote operation
Internal ARM 710A cached processor assures fast operation
Four status LEDs for observing operation
Flash memory for easy firmware updates to next generation ARM cores
Vendor: Embedded Performance, Inc.

23. uClinux 개발환경 (cont’) JTAG Emulators Wigglers Multi-ICE OPENice-A900
Raven
Macraigor System
AIJI System
ARM

24. uClinux 개발환경 (cont’) Building Software
GNU Cross Development Tools (gcc, as, ld, and etc.)
add an option “-gstabs” to an assembler
add an option “-g” to a compiler
How to execute and debug the built image
by Monitor Program : > download into a target RAM via user program (serial or Ethernet) > Debug : manually insert some debug codes such as print function
by JEENI (EmbeddedICE) : > download into a target RAM or a RAM included in an ICE via gdb > Debug : can use advanced debug features, breakpoint, watchpoint and etc., via gdb

25. uClinux 개발환경 (cont’) Debugger Linux Platform (gdb or DDD) Breakpoints
Watchpoints
Backtrace
Disassembled code
Examine Memory
Examine Registers
GNU DDD is a graphical front-end for command-line debuggers such as GDB, DBX, WDB, Ladebug, JDB, XDB, the Perl debugger

26. Special Function Registers Memory Map after Initialization
uClinux 개발환경 (cont’)
Initialize Debugger (change memory map) 0x
USB & LEDs (CS4) 4K
0xFFFFFFFF 0x
Cache RAM
0xFFF00000
Special Function Registers 0x
0xFF800000
LCD (CS3) 4K 0x 0x 1M
EEPROM (CS2/0) 0x 0x 0x
FLASH (blk 2) (CS0/2) 0x
FLASH (blk 1) (CS0/2) 4M 0x
CS 0 0x
FP-DRAM (CS1)
16M 0x 0x
Memory Map after Reset
Memory Map after Initialization
This memory map is for NetSilicon NET+40 MCU.

27. uClinux 개발환경 (cont’)
Initialize Debugger by script (When FLASH is at CS0)
target rdi e=
#target rdi /dev/ttyS0
set {long}0xffb00000 = 0xC004a000
set {long}0xffc00000 = 0x0dc00000
set (long)0xffc00054 = 0xfffffa40
set (long)0xffc00050 = 0x
set (long)0xffc00044 = 0xfffffa40
set (long)0xffc00040 = 0x
set (long)0xffc00034 = 0xfff80a40
set (long)0xffc00030 = 0x
set (long)0xffc00024 = 0xff000090
set (long)0xffc00020 = 0x
set (long)0xffc00014 = 0xff8002f4
set (long)0xffc00010 = 0x
Connect I/F (eth)
Connect I/F (serial)
System Ctrl.
Memory Mod.
USB&LED (CS4)
LCD (CS3)
EEPROM (CS2)
DRAM (CS1)
FLASH (CS0)
“.gdbinit” script file
Script for GDB

28. DYAUS DYAUS Product Family DBoot Bootloader emnux Kernel
Software Packages

29. DYAUS™ DYanamic All User Support uClinux kernel-2.0.38pre7/2.4.17uc0
DYAUS™ Series
DYAUS-Exx : Embedded Linux Evaluation Board
DYAUS-Rxx : ROM Emulator
DYAUS-SE : CASE Tool (It’s renamed to Cstate™)

30. DYAUS Product Family DYAUS™-E100 DYAUS™-E200 DYAUS™-E210
NetSilicon NET+40
1 Parallel, 2 RS-232, 1 Ethernet, etc.
DYAUS™-E200
Samsung S3C4530A
2 RS-485, 1 RS-232, 1 Ethernet, etc.
DYAUS™-E210
VME Bus, 2 RS-232, 2 Ethernet, etc.

31. DBoot Bootloader Supported processor(s): Features: ARM7TDMI based SoC
NetSilicon NET+40 and Samsung S3C4530A
Features:
“dsh” command prompt for user interface
download the image through the serial port using XMODEM or through the Ethernet port using TFTP protocol
execute the program from Flash or DRAM
write the image into Flash and erase block/sector/all
reload from Flash into DRAM
able to set the network configuration
able to edit memory information
support the diagnostic tests (irq, printer)

32. DBoot Bootloader (cont’)

33. emnux Kernel derived from uClinux kernel
It has two version, 2.0(2.0.38pre7) and 2.4(2.4.17uc0)
/arch
/armnommu
/i196
/m68knommu
/drivers
/kernel
/boot
/mach-netarm
/kernel
/lib
/mm
/lib
/init
/ipc
/fs
/kernel/linux
/include
/asm-armnommu
/linux
/net
/mm
/mmnommu
/arch-netarm
/proc-netarm
/net
/scripts

34. Software Packages /usr/local arm-dyaus
cross development environment dir.
for ARM7TDMI
/arm-elf
/bin
/include
emnux-2.4
kernel
emnux kernel
tools
cross development tool sources
uC-libc
the older uC-libc
userapps
application programs
/apps
busybox, tinylogin, inetd (uClibc)
/uc_apps
mount, ftp, ping (uC-libc)
/build
root file system
/disk
root directory
/bin
/etc
/usr

35. Demonstration emnux-2.4 on DYAUS-E100 Boa embedded web server
C CGI program

36. Bookmarks uClinux uClinux Official Site The uClinux Directory
The uClinux Directory
uClinux Software
uClinux Vendors
EmbeddedWeb Co., Ltd.
Arcturus Networks Inc.
Snap Gear Inc.
Lineo, Inc.

37. Bookmarks (cont’) JTAG Emulator Vendors Embedded Performance, Inc.
Macraigor System
AIJI System Co., Ltd.
Useful Sites
uClinux for Samsung S3C4510A
uClinux for Samsung S3C44b0x
uClinux on the NET V850E

38. Bookmarks (cont’) Cross Development Environment uClibc genromfs
genromfs

39. Thanks for your interest!!
Don’t hesitate to contact!
Duke Cho