Qemu Syborg Workshop September 2009

QEMU/Syborg Workshop Martin Trojer [email protected]

Agenda (1/2) 1. 

Build Syborg ROMs    

2. 

Using the PDK 2.0.d / tip kernelhwsvr + syborg Using RVCT2.2 and raptor

Debugging with QEMU      

Stop-mode and Run-mode ELF4ROM GDB command line debugging    

 

Debugging user-side apps Debugging the kernel / device drivers

Debugging with Eclipse

Copyright © 2009 Symbian Foundation.

2

Agenda (2/2) 3. 

How QEMU peripherals work    

4. 

Adding new peripherals to syborg Adding / modifying Symbian device drivers

Building QEMU itself        

Setting up a MinGW environment Installing / building necessary components Building QEMU Debugging QEMU

SVP = Symbian Virtual Platform = QEMU + syborg models / baseport Copyright © 2009 Symbian Foundation.

3

Building ROMS

Copyright © 2009 Symbian Foundation.

4

Building Syborg ROMS -- Getting the platform Basically following the QEMU/syborg Wiki with some more details; http://developer.symbian.org/wiki/index.php/SYBORG/QEMU 1. 

Get the PDK We will be using 2.0.d (click ‘previous releases’) http://developer.symbian.org/main/tools_and_kits/downloads/view.php?id=1

2.  3. 

You will only need the following packages; binaries_armv5.zip, binaries_epoc.zip, binaries_epoc_additional.zip, binaries_bldmefirst.zip Extract zips into a folder ‘FF’ Subst a drive-letter $subst X: FF

4. 

Get remaining sources from Hg tip. $X: $mkdir sf\os $cd \sf\os $hg clone https://developer.symbian.org/sfl/FCL/sf/os/kernelhwsrv $hg clone http://developer.symbian.org/oss/FCL/interim/QEMU

Copyright © 2009 Symbian Foundation.

5

Building Syborg ROMS -- Getting the tools 1.  2.  3. 

Download the “platform tools” from the PDK page tools_epoc.zip Unzip in the same folder as the platform Get raptor From the PDT download page http://developer.symbian.org/main/tools_and_kits/downloads/view.php?id=4

4. 

5. 

Get a cpp.exe to be used by rombuild. There is one in raptor, but it gives a lot of warnings, and doesn’t work with debugging A vanilla cpp.exe from mingw works better Make sure you have RVCT2.2 installed

Copyright © 2009 Symbian Foundation.

6

Building Syborg ROMS -- Applying Patches 1. 

Apply attached patch in #bug301 http://developer.symbian.org/bugs/show_bug.cgi?id=301

3. 

Edit the file \epoc32\include\bldvariant.hrh Change the ‘<‘ and ‘>’ in the include statements to “ (depending on that cpp.exe you are using)

4. 

Edit the file sf\os\kernelhwsrv\kernel\eka\rombuild\user.iby Comment out the “file=“ lines for btrace.exe and dptest.dll

Copyright © 2009 Symbian Foundation.

7

Building Syborg ROMS Compiling the Source 1.  2.  3.  4.  5.  6. 

$ $ $ $ $ $

set EPOCROOT=\ set SBS_HOME= set PATH=%PATH%;\epoc32\gcc\bin X: cd \sf\os\QEMU\baseport\syborg \bin\sbs –c armv5

Building the ROM images 1.  $ cd \sf\os\kernelhwsvr\kernel\eka\rombuild 2.  $ rom –v syborg –i armv5 –b udeb –noheader 3.  $ rom –v syborg –i armv5 –b urel --noheader Copyright © 2009 Symbian Foundation.

8

Running ROMs in QEMU 1. 

Download and unzip the binary version of QEMU http://developer.symbian.org/wiki/images/b/bb/Symbian-qemu-0.9.1-12.zip

2. 

$ arm-none-symbianelf-qemu-system.exe -kernel X:\sf \os\kernelhwsrv\kernel\eka\rombuild\SYBORGARMV5D.IMG -M X:\sf\os\QEMU\baseport\syborg\syborg.dtb

It’s all worth it, innit?  Copyright © 2009 Symbian Foundation.

9

Debugging with QEMU

Copyright © 2009 Symbian Foundation.

10

Debugging with QEMU -- stop-mode and run-mode Simulator / QEMU IDE (Carbide / Eclipse)

Symbian Debug Agent TRK / GDB Runmode

Debugger

Debug Driver

KDebug

Debug “Stub” GDB Stop-mode

  Stop-mode; When you hit a breakpoint the CPU stops Like using a ICE-box like Lauterbach or the Emulator Supports user and kernel side debugging  Run-mode; when you hit a breakpoint only that process stops Supports “dynamically loaded code” Only supports user side code Copyright © 2009 Symbian Foundation.

11

Debugging with QEMU -- ELF4ROM  

How a Symbian ROM is built SymApp.cpp

App1.exe App2.exe SymApp.exe

compiler SymApp.o rombuild linker

Rom.img

Rombuild.log

SymApp.sym elf4rom

elf2e32 postlinker

Rom.elf

SymApp.exe

 

Problem; The ROM contains NO symbol or debug info! Not debug-able (without debugger hacks)

Copyright © 2009 Symbian Foundation.

12

Debugging with QEMU -- Running ELF4ROM  

1.  2.  3. 

Get the ELF4ROM executable (embedded in \sf\os\QEMU\docs\wiki\ELF4ROM.doc) -- source to be contributed $ cd \sf\os\kernelhwsvr\kernel\eka\rombuild $ rom –v syborg –i armv5 –b udeb –noheader $ elf4rom.exe –I SYBORGARMV5D.IMG –l ROMBUILD.LOG –o SYBORGARMV5D.ELF –p 0x0

ELF4ROM might warn about the ROMBUILD.log file. Change the header to bypass. Yeah, I will fix and rebuild…

Copyright © 2009 Symbian Foundation.

13

Debugging with QEMU -- GDB command-line  

Get the “arm-elf-gcc/gdb” tool chain from yagarto.de http://yagarto.de/#download

1. 

$ arm-none-symbianelf-qemu-system.exe -kernel X:\sf\os \kernelhwsrv\kernel\eka\rombuild\SYBORGARMV5D.ELF -M X:\sf\os \QEMU\baseport\syborg\syborg.dtb –S –s

2. 

$ arm-elf-gdb X:\sf\os\kernelhwsrv\kernel\eka\rombuild\SYBORGARMV5D.ELF

3. 

(gdb) (gdb) (gdb) (gdb) (gdb)

4.  5.  6.  7. 

tar rem localhost:1234 b snapapp.cpp:47 b svpsnapdriver.cpp:205 c i s

Who needs anything more than GDB command line?  Copyright © 2009 Symbian Foundation.

14

Debugging with QEMU -- Installing Eclipse 1. 

Download in install the latest Eclipse/CDT (for C/C++ developers) release (at the time of writing this Galileo) http://www.eclipse.org/downloads/

2. 

Install the “gdbjtag” plug-in        

In eclipse UI click "Help" -> "Install New Software" "Work with" type "http://download.eclipse.org/tools/cdt/releases/galileo". "CDT MAin Features" and "CDT Optional Features“ –> "Eclipse C/C++ GDB Hardware Debugging“ Next and Finish

Copyright © 2009 Symbian Foundation.

15

Debugging with QEMU -- Eclipse project 1. 

2.  3.  4.  5.  6.  7. 

Create eclipse project Create a new directory under your eclipse workspace directory and copy your elf file to the directory "File" -> "New" -> "C++ project" Expand the "Makefile Project" and select the "Empty Project". In toolchains box select the MinGW GCC. Type the directory name where your elf file is located to the "Project name" field Right click the project you just created in Project Explorer view and select "Properties" “C/C++ Build” -> "Settings“, tick the "GNU Elf Parser". Select the "GNU Elf Parser" option to make the commands addr2line and c++filt visible. Change the addr2line to armelf-addr2line and c++filt to arm-elf-c++filt.

Copyright © 2009 Symbian Foundation.

16

Debugging with QEMU -- Debug Launch configuration 1.  2.  3. 

4.  5.  6.  7. 

“Run" -> "Debug Configurations" New "GDB Hardware Debugging" In the resulting menu choose "Main" tab. Give a good name to your configuration. Choose the project you created to "Project" box and give your elf file name in "C/C++ Application" box. Choose "Debugger" tab. Type in arm-elf-gcc to GDB Command box. Remote Target; “Generic”, “localhost”, “1234” Choose "Startup" tab. Untick Reset and Halt. Run Commands “c”

Copyright © 2009 Symbian Foundation.

17

Debugging with QEMU -- Debug Session 1.  2. 

3. 

Set one or many breakpoints in Eclipse Start QEMU $ arm-none-symbianelf-qemu-system.exe -kernel X:\sf \os\kernelhwsrv\kernel\eka\rombuild\SYBORGARMV5D.ELF -M X:\sf\os\QEMU\baseport\syborg\syborg.dtb –S –s Launch the debug session in Eclipse

The sheep says; WOW!

Copyright © 2009 Symbian Foundation.

18

How QEMU Peripherals work

Copyright © 2009 Symbian Foundation.

19

How QEMU Peripherals Work

Copyright © 2009 Symbian Foundation.

20

How QEMU Peripherals Work -- dts / dtb files  

A Symbian Virtual Platform board configuration is described using Flattened Device Trees. These are based on the device trees used by OpenFirmware (IEEE 1275-1994) systems.

 

The DTS file describes “the board” Memory map, what peripherals, configuration of the peripherals etc DTB are a binary version of DTS parse-able by machines

   

The DTB file is exposed to the baseport by the “platform” device (so the device drivers can get the configurations etc)

Copyright © 2009 Symbian Foundation.

21

How QEMU Peripherals Work -- peripherals  

1.  2.  3. 

4. 

QEMU peripherals can be written in C or Python We are using the python models (share\qemu\plugins) Add the file “syborg_hello.py” to share\qemu\plugins Edit qemu_arm_plugins.py, add “import syborg_hello.py” Edit “syborg.dts” Replace the item serial@3 with hello@0 { compatible = "syborg,hello"; reg = ; }; $ arm-none-symbianelf-dtc.exe syborg.dts –O dtb –o syborg.dtb

Copyright © 2009 Symbian Foundation.

22

How QEMU Peripherals Work -- device drivers    

 

Since we are replacing an existing peripheral we don’t have to change the bootstraps memory map in the super page We need to add / change a device driver to access the new peripheral (for simplicity, let’s hack the snapshot device driver) In svpsnapdriver.cpp, function DSVPSnapChannel::SaveVM add *(volatile TUint32*)(KHwBaseUart3) = 15;

Copyright © 2009 Symbian Foundation.

23

How QEMU Peripherals Work -- trying it out 1.  2.  3.  4. 

Fire up raptor to rebuild the sources Re-build the ROM Start the new ROM in QEMU (eshell) snapapp

Copyright © 2009 Symbian Foundation.

24

Building QEMU

Copyright © 2009 Symbian Foundation.

25

Building QEMU -- About the “Syborg QEMU”  

We are using a slightly modified version of QEMU, but in theory the “offical” version should also work; http://www.nongnu.org/qemu/ The QEMU ToT contains the syborg peripherals.

 

The stuff that hasn’t made into QEMU mainline yet is interesting enough for us to keep a copy around Python support, skinning etc

 

The SF QEMU Hg repo contains all QEMU sources and the libraries it depends on. Since they are all standard libraries you can either install pre-build versions (handy on *ix) or build them yourself

Copyright © 2009 Symbian Foundation.

26

Building QEMU -- Getting MinGW environment    

1.  2.  3. 

QEMU builds on *ix and MAC OSX systems … easy It also builds on win32 in MinGW (and probably Cygwin) … harder Go to http://sourceforge.net/projects/mingw/files/ Download and run the MinGW Installer Install a minimal configuration Download and add    

4. 

MSYS Base System (msysCore, coreutils, make) bison, flex, regex-1

Edit <mingw>/etc/profile, add export CFLAGS="-I/usr/local/include“ export LDFLAGS="-L/usr/local/lib“

5.  Copyright © 2009 Symbian Foundation.

27

Building QEMU -- build the libraries, Python, QEMU 1.  2.  3. 

4.  5.  6. 

Start msys.bat Build the libraries in this order; expat, zlib, libpng, libsdl, dtc-trunk $ ./configure -–prefix= $ make $ make install There are Python sources available, but also a win32 binary version (let’s use that one!) Edit qemu-symbian-svp/configure Line 1036: PYTHON_LIBS="-L$with_python/libs -lpython26" $ ./configure -–target-list=arm-softmmu –-withpython==/x/sf/os/QEMU/symbian-qemu-0.9.1-12/pythonwin32-2.6.1 $ make

Copyright © 2009 Symbian Foundation.

28

Building QEMU -- running home-built QEMU    

The QEMU executable is called arm-softmmu\qemu-systemarm.exe When running it make sure that you have;      

From a mingw prompt (so you have all dlls available) Python26.dll in your path The plugins/ folder at the some dir at the exe The python peripherals

Copyright © 2009 Symbian Foundation.

29

Debugging QEMU  

 

Now that you (perhaps) has a debug build of QEMU you can debug QEMU (while debugging code in the simulator – very meta I know) This can be very useful when writing peripherals and device drivers (I used it a lot when creating syborg)

 

Download and install MinGW GDB “Source-level debugger”

 

Start arm-softmmu-qemu.exe from gdb and debug as normal (probably your peripherals) Eclipse/CDT can be used as well (and works great)

 

Copyright © 2009 Symbian Foundation.

30

Other Stuff

Copyright © 2009 Symbian Foundation.

31

Stuff we didn’t talk about (1/2)            

   

More FDT details The Host File System The Platform Device QEMU skinning (put phone skin around it) Virtio peripherals (used by the Ethernet device) The NAND flash device Using python peripherals to wrap binary peripherals More details on how to write C peripherals

Copyright © 2009 Symbian Foundation.

32

Stuff we didn’t talk about (2/2)    

S60 GUI builds in QEMU NGA in QEMU

Copyright © 2009 Symbian Foundation.

33