LinuxKernel Training
Refrences:
$ git cloneGit://igloocommunity.org/git/kernerl/igloo-kerner.git
http://igloocommunity.org/support/Technical_documentation
https://wiki.linaro.org/Platform/Android
https://www.islief.com/mediawiki/index.php/Snowball
git clone git://igloocommunity.org/git/boot/u-boot-ux500.git
Getting the first Open Source GSMstack in Linux; this is an example from Marcin which develop an gsm proting on linux
This is my summary after training, detail can see the video.
Lauterbach(H) ----- trace32(S)
Lauterbach UserGuide
preconditions,
1. u8500 snowboard
2. lauterbach emulator
install the software
sudo dpkg -i semc-trace32-sw_33438.1202091+git20120215.ad792810_amd64.deb
Edit a shell to start trace32
start.sh
#!/bin/sh
xset +fp /opt/t32/fonts
xset fp rehash
/opt/t32/bin/pc_linux/t32marm -c /opt/t32/bin/pc_linux/config.t32 -s /opt/t32/demo/practice/t32.cmm
the content of config.t32,
;Generic config file for T32
OS=
ID=T32
TMP=/tmp
SYS=/opt/t32/
PBI=
USB
CORE=1
SCREEN=
FONT=SMALL
HEADER=Generic Trace32
LICENSE=/opt/t32/license.t32
t32.cmm will add some tool bar.
B:: ; This presents that command in trace32
B:: cd ~snow ;entry your work path
B::do start_core0.cmm ;start-core0 do some context init
start_core0.cmm,
; Start-Up Script for Cortex-A9 of A9500 on Snowball Board from ST Ericsson
; PEG, June 2011
RESet
SYStem.CPU A9500
CORE.ASSIGN 1
SYStem.Mode Attach
if run()
Break
download and compile u-boot
git clone git://igloocommunity.org/git/boot/u-boot-ux500.git
change u-boot delay time,
$ vim common/main.c
s = getenv ("bootdelay");
bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
bootdelay = 10;
$make CROSS_COMPILE=arm-linux-gnueabi- distclean
$make u8500_snowball_config
$make CROSS_COMPILE=arm-linux-gnueabi- ;apt-cache arm-linux if there is not, apt-get install arm-linux-gnueabi-
B::data.load u-boot-ux500/u-boot ;load the symbol file
Here, we can reorder it like this,
1. power supply snowborad
2. B::do start_core0.cmm ; here will stop, becauseif run() Break
3. B::data.load u-boot-ux500/u-boot
Next, start snowboard, minicom to connect the snowboard console.
-
minicom -D /dev/ttyUSB0 ( ls /dev/ttyUSB* to know what usbserial port is ) -
Type minicom -s to start it in setup mode.Select “serial port setup”and press 'a' to change the Serial Device to /dev/ttyUSB0.Press 'e' and select speed 115200 no parity 8 data bits ,one stop bit (1152008N1)and press enter. Select No hardware flow control and no software flow control.
in minicom console, will print out
CPU: ST-Ericsson db8500 v2 (Dual ARM Cortex A9) 998.400 Mhz
I2C: ready
DRAM: 1 GB
MMC:
MCDE: startup failed
sec_bridge: ISSWAPI_FLUSH_BOOT_CODE: 2
EMMC: 0, MMC: 1
In: serial
Out: serial
Err: serial
Net: smc911x-0
Hit any key to stop autoboot: 7
Hit any key, will go into snow emmc console,
Snowball $ version
U-Boot 2009.11-dirty (Apr 26 2012 - 15:02:02)
Snowball $ mmcinfo
Device: EMMC
Manufacturer ID: 13
OEM: 100
Name: Tran Speed: 25000000
Rd Block Len: 512
MMC version 4.0
High Capacity: Yes
Capacity: 3791650816
Bus Width: 8-bit
In B::data.list window, change the mode and find this line,
ldr pc,_start_armboot @jump to c code
Right click this line, select
go till, will go to void start_armboot(void) entry point, this is the uboot start point. Or from menu, run->go till-> select start_armboot(void).
When "Loading kernek image...." appears in minicom console, in Trace32, Break
B::do linux-attach.cmm, ;will start debug kernel after uboot
WinCLEAR
RESet
SYStem.CPU A9500
SYStem.Option DACR ON ; give Debugger global write permissions
TrOnchip.Set DABORT OFF ; used by Linux for page miss!
TrOnchip.Set PABORT OFF ; used by Linux for page miss!
TrOnchip.Set UNDEF OFF ; my be used by Linux for FPU detection
SYStem.Option MMUSPACES ON ; enable space ids to virtual addresses
TERM.METHOD COM COM4 115200. 8 NONE 1STOP NONE
TERM.MODE VT100
TERM.SCROLL ON
TERM.SIZE 80 1000
WINPOS 76.0 25.0 80. 24. 0. 0. TermWin
SCREEN.ALWAYS
TERM
SYStem.Mode Attach
if run()
Break
; Load the Linux kernel symbols into the debugger
print "loading Linux kernel symbols..."
Data.LOAD.Elf vmlinux /gnu /nocode
; Open a Code Window -- we like to see something
WINPOS 0. 0. 75. 20.
Data.List
screen
print "initializing debugger MMU..."
MMU.FORMAT LINUX swapper_pg_dir 0xc0000000--0xdfffffff 0x00000000
TRANSLATION.COMMON 0bf000000--0ffffffff ; common area for kernel and processes
TRANSLATION.TableWalk ON ; debugger uses a table walk to decode virtual addresses
TRANSlation.ON
print "initializing multitask support..."
TASK.CONFIG ~~/demo/arm/kernel/linux/linux ; loads Linux awareness (linux.t32)
MENU.ReProgram ~~/demo/arm/kernel/linux/linux ; loads Linux menu (linux.men)
HELP.FILTER.Add rtoslinux ; add linux awareness manual to help filter
sYmbol.Autoload.CHECKLINUX "do autoload.cmm "
Go
seems the upper B::do linux-attach.cmm step is not needed.
Download and compile kernel
$ git clone git://igloocommunity.org/git/kernel/igloo-kernel.git
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- u8500_android_defconfig
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- menuconfig ;;裁剪kernel
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- uImage -j3 ;; 生成image
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- modules ;; compile modules
B::data.load vmlinux /nocode ;load kernel ELF file
in B::sYmbol.Browse window, can see start_kernel function
at the below picture, we can see the break impl isSOFT, right click it, must change it to Onchip, otherwise, can not go till start_kerner(void).
Below is come records I did, can read it as a reference.
加載自己的uboot
u-boot.bin
in Trace32 tools,
d.dump 0x56000
d.l 0x56000
加載uboot到ram
B:: data.load u-boot/u-boot.bin 0x5600000
;load it into start point address 0x5600000
File->set PC here “0x56000”
$ cd u-boot
$ readelf –h u-boot
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: DYN (Shared object file)
Machine: ARM
Version: 0x1
Entry point address: 0x0
Start of program headers: 52 (bytes into file)
Start of section headers: 563080 (bytes into file)
Flags: 0x5000000, Version5 EABI
Size of this header: 52 (bytes)
Size of program headers: 32 (bytes)
Number of program headers: 2
Size of section headers: 40 (bytes)
Number of section headers: 23
Section header string table index: 20
B::data.load u-boot/u-boot
B::y.b
#listsymbole
readelf -h vmlinux
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: EXEC (Executable file)
Machine: ARM
Version: 0x1
Entry point address: 0xc0008000
Start of program headers: 52 (bytes into file)
Start of section headers: 91517696 (bytes into file)
Flags: 0x5000002, has entry point, Version5 EABI
Size of this header: 52 (bytes)
Size of program headers: 32 (bytes)
Number of program headers: 3
Size of section headers: 40 (bytes)
Number of section headers: 39
Section header string table index: 36
編譯uboot可以選擇不優化notoptimize，OPTFLAGS -o0,這樣跟蹤時可以line by line to go
啓動trace32的模擬器模式
./t32marm -c config_sim.t32
cp config.732 to config_sim.t32, change PBI=USB to PBI=SIM