Samuel Jacob's Weblog

NGX’s USB ARM JTAG

This post describes the steps needed to make NGX’s USB ARM JTAG to work with OpenOCD in windows 7. This JTAG is compatible with colink JTAG and works with IAR Workbench and Keil uVision. To use with these IDEs there is a well defined methods/plug-ins available in the product page and in internet. However to use this JTAG with OpenOCD there is scarce resource in the internet.

OpenOCD can be used to low level debugging, source level debugging (through GDB) and can be used for flashing. OpenOCD exposes a command line interface which can be accessed through telnet. It also provides remote GDB server which also can be reached through TCP connection.

Steps needed for Windows:

1. Plug-In the JTAG to a available USB connector
2. Download libusb-win32
3. Extract libusb-win32 to a folder and run “inf-wizard.exe”
4. Select “USB Serial Converter A” and install driver
5. Download and install OpenOCD
6. Attach the JTAG probe to your target ARM board and poweron the target board
7. Create a openocd configurations file (see at the end)
8. Run openocd.exe –f
9. Run putty or telnet and connect to port localhost:4444

After this the target board will respond to JTAG commands which can be issued through the telnet session.

For GDB debugging, you need a cross compiled GDB(arm-none-eabi-gdb).
After launching arm-none-eabi-gdb.exe run target remote localhost:3333 to start remote debugging.
You can execute low level JTAG commands from GDB by using monitor command.

Flashing can be done using the following commands:
[shell]
reset
halt
sleep 200
wait_halt
flash probe 0
flash info 0
flash write_image erase unlock
sleep 200
reset run
[/shell]

OpenOCD configuration file:
[shell]
# openocd configurations
telnet_port 4444

# gdb configuration
gdb_port 3333

# cpu configuration
source [find target/lpc1768.cfg]

# interface configuration
interface ft2232
ft2232_vid_pid 0x0403 0x6010
ft2232_device_desc “NGX JTAG”
ft2232_layout “oocdlink”
ft2232_latency 2
[/shell]

Eva is an expression evaluator developed as a cross platform utility. It is written using ANTLR(targetting C), gcc. Eva supports all C expressions including bitwise operations. It is created to aid developers to convert between hexa to binary operations easily. The main goal was very simple code base ~1000 lines.

The UI part was initially coded using wxWidgets and now contains – simple command line interface, wxWidgets and Windows specific GUI interface. Here is a video demonstrating different operations possible with Eva.

http://www.youtube.com/watch?v=m7ieVDEkdZ4

Here is the source code – https://bitbucket.org/samueldotj/eva

While investigating about gcc flag “-fprofile-arcs”, I came to know about a new(to me) gcc flag and this blog entry is about it. For any large C project it is hard to learn/find call graph through code walk. From C prospective unless otherwise you put a printf in each function entry/exit it is hard to find the call trace.

GCC and ICC has a wonderful option “-finstrument-functions” to solve this. This option instructs the compiler to emit instructions to call a external function on each function’s entry/exit. Defining these two functions like the following and adding the above option -finstrument-function to your makefile will do the magic.

[c]
void noinstrument __cyg_profile_func_enter(void *this_fn, void *call_site)
{
printf(“%p called from %p\n”, this_fn, call_site);
}

void noinstrument __cyg_profile_func_exit(void *this_fn, void *call_site)
{
printf(“%p returns\n”, this_fn);
}
[/c]

Of course, you can do anything in these functions, for simplicity sake I just defined them as printfs.

In this post, I will explain how to easy it is to compile/port C programs and makefiles designed for GCC(GNU compiler collection) can be used with ICC(Intel C Compiler)

The necessity for using ICC happened to me because gcc was generating too big object files. Ace is using ACPI-CA(http://acpica.org/) as it is ACPI driver. After compilation the ACPI library is around 7M in debug version and around 500K in non-debug version. But from http://acpica.org/download/changes.txt it seems Microsoft C compiler produce smaller code.
[shell]
Non-Debug Version:  81.2K Code, 17.0K Data,  98.2K Total
Debug Version:     155.8K Code, 49.1K Data, 204.9K Total
[/shell]

So I decided to try “Intel Compiler” as replacement for GCC. Things were easy, since icc has options which is similar to gcc.
You can get the details of portability options from icc documentation – http://www.intel.com/software/products/compilers/docs/clin/main_cls/index.htm.

I just changed my make.conf file to check the compiler in use and use appropriate options. I removed -fno-leading-underscore and –Wall. I removed –Wall because it was giving lot of warnings, we have to fix our code sometime soon. I removed -fno-leading-underscore because there is no equivalent option in icc, however icc does not adds underscores to symbols anyway.

I added –O1 option because the kernel was panicked during boot with invalid opcode exception, I believe it was because of some MMX register usage by icc. So I settled with –O1 now.
[shell]
ifeq ($(CC),gcc)
DEBUG_FLAGS= -gdwarf-2 -g3
CFLAGS+= -Wall -Wno-multichar $(DEFINES) -nostartfiles -ffreestanding -funsigned-char -fno-leading-underscore -c -fno-stack-protector $(DEBUG_FLAGS) $(CUSTOM_FLAG)
else
DEBUG_FLAGS= -gdwarf-2 -g
CFLAGS+= -O1 -Wno-multichar $(DEFINES) -nostartfiles -ffreestanding -funsigned-char -c -fno-stack-protector $(DEBUG_FLAGS) $(CUSTOM_FLAG)
endif
[/shell]

I also made some static variables in kernel/i386/gdb_stub.c to non-static because icc appends .0 to static variables but it forgets the same name when referenced in a inline assembly code in the same file. After removing the static attribute it is working fine.

Compilation time:
gcc compiler took the following time to compile Ace source code.
[shell]
real 0m51.125s
user 0m36.975s
sys 0m11.185s
[/shell]

icc compiler took the following time to compile Ace source code.
[shell]
real 1m44.366s
user 0m59.107s
sys 0m20.946s
[/shell]

Size:
Gcc produced double the size of kernel.sys produced by icc. (I used GNU linker(ld) and ar).
gcc output size:
[c]
$ ls -lh /home/samuel/Projects/Ace3/obj/
-rw-rw-r– 1 samuel samuel 372K 2008-11-22 18:17 acpi.a
-rw-rw-r– 1 samuel samuel 545K 2008-11-22 18:17 arch.a
-rwxrwxr-x 1 samuel samuel 1.3M 2008-11-22 18:17 kernel.sys
-rw-rw-r– 1 samuel samuel 62K 2008-11-22 18:17 libds.a
-rw-rw-r– 1 samuel samuel 40K 2008-11-22 18:17 libheap.a
-rw-rw-r– 1 samuel samuel 39K 2008-11-22 18:17 libstring.a
-rw-rw-r– 1 samuel samuel 9.5K 2008-11-22 18:17 libsync.a
-rw-rw-r– 1 samuel samuel 91K 2008-11-22 18:17 pic.a
-rw-rw-r– 1 samuel samuel 23K 2008-11-22 18:17 pit.a
-rw-rw-r– 1 samuel samuel 21K 2008-11-22 18:17 rtc.a
[/c]
icc output:
[c]
$ ls -lh /home/samuel/Projects/Ace3/obj/
-rw-rw-r– 1 samuel samuel 352K 2008-11-22 16:25 acpi.a
-rw-rw-r– 1 samuel samuel 230K 2008-11-22 16:24 arch.a
-rwxrwxr-x 1 samuel samuel 528K 2008-11-22 16:25 kernel.sys
-rw-rw-r– 1 samuel samuel 38K 2008-11-22 16:23 libds.a
-rw-rw-r– 1 samuel samuel 22K 2008-11-22 16:23 libheap.a
-rw-rw-r– 1 samuel samuel 21K 2008-11-22 16:23 libstring.a
-rw-rw-r– 1 samuel samuel 11K 2008-11-22 16:23 libsync.a
-rw-rw-r– 1 samuel samuel 19K 2008-11-22 16:24 pic.a
-rw-rw-r– 1 samuel samuel 8.4K 2008-11-22 16:24 pit.a
-rw-rw-r– 1 samuel samuel 13K 2008-11-22 16:24 rtc.a
[/c]

Conclusion: So it is easy to switch to icc instead of gcc.