This appendix describes topics that are specific to the GNAT for PikeOS, a cross-development ARINC-653 system provided by SYSGO.
Kernel Configuration for PikeOS¶
There are two possible ways to configure a PikeOS kernel:
SYSGO’s set of command-line tools: pikeos-cloneproject, pikeos-configure, etc.
CODEO, a visually-oriented Integrated Development Environment based on the Eclipse framework.
In the following sections, we will explain how to use these tools to build a PikeOS kernel so that Ada applications can be run on it. The procedures will mostly use CODEO; to know more about PikeOS kernel configuration, refers to the PikeOS user manual Installing and Using PikeOS.
In order to debug any application on target, a partition should run a
muxa provides several development
services, such as a target console, and some debug channels that can be
connected to AdaCore’s debugger.
This will be illustrated by a simple scenario. The following instructions should help you build a simple kernel integration project in which Ada application can be run.
Creating a PikeOS kernel integration project¶
To setup your PikeOS kernel project, please consult the PikeOS User Manual
section 8 :
Basic Steps of the PikeOS Build Process. Be sure to pick the
devel-pikeos-native as it contains a project pre-configured with
the major development features.
PikeOS maximum priority setting¶
You should now have a basic integration project; you can then configure it for Ada Ravenscar applications.
In order to run Ada tasking applications on a PikeOS process, you
should make sure that this process can handle 240 priority levels. To
do so, in the
Project Explorer, double-click on
vmit.xml. This will open the
Topology View, in
ProcessList, then click on
Proc_pikeos. In its attribute, change
MaxPrio to 240.
Then click on
pikeos. CODEO warns you about the
fact that the process
Proc_pikeos has a greater priority than its
partitions; so upgrade the maximum priority for the partition as well.
MaxPrio to 242. Then save your modifications.
Please read comments in
p4ext-cert-app.c runtime file for
guidance on using interrupts.
PikeOS muxa configuration¶
As explained earlier, console and debugging functionalities are
provided by a component called
muxa that comes in two parts:
one running on target, one running on host. This section will focus on
how to configure your kernel integration project in order to include
this component on target. How to run the host part will be explained
latter in this chapter (in section
Debugging an Ada application on PikeOS).
In the previously-created integration project in CODEO,
project.xml.conf in the
to open the
PikeOS Project Configuration. Expand
service and click on
will open a panel
Configuration Options: muxa. Change the settings
to match your host/target configuration. In our case, as we are building
a kernel for QEMU, the following values will do:
HostIP: IP address of your host;
HostPort: port used by the host
muxa; say, 1501;
TargetIP: IP of the target as seen from target; say, 10.0.2.1 for QEMU;
TargetPort: Port on which the target
muxais listening; say, 1500;
GatewayIP: IP of the gateway from target; say, 10.0.2.2 for QEMU;
ConfigPort: Port of
muxa’s back office; say, 1550.
You can also change these settings from the command line, with the command
$ pikeos-configure --editor
In order to have debug support for your particular user application, you
will also need to make sure that it has access to the whole file system
muxa partition. This is handled in the
To access to it, click on
vmit.xml in the
go your user partition: in this example, it is named
Partition -> pikeos. Expand this node, then the node
FileAccessList and check that a node
has all access rights (Stat, Read. Write, Read-Write). If not,
you may add it by right-clicking on
FileAccessList and selecting
Your kernel integration project is now properly configured to host an Ada application. The following section will tell you how to build such an application and how to link it to the kernel.
Building an Ada application on PikeOS¶
This section will give a basic example to illustrate how an Ada
application targeting PikeOS can be built. Consider
the following Ada program, to be copied in a file named
with GNAT.IO; use GNAT.IO; procedure Hello is begin Put_Line ("Hello from Ada!"); end Hello;
On ARM PikeOS, you can then build the Ada program and link it against this global handler with this command:
$ gprbuild --target=arm-sysgo-pikeos --RTS=embedded -g hello.adb
A similar command would be used on other CPUs; only the target and the prefix of tools would change (e.g. powerpc-sysgo-pikeos-gcc). In the rest of this tutorial, we will use arm-sysgo-pikeos; adapting it to your platform is just a matter of changing the prefix.
This will generate a file
hello. You should then add this executable
to your kernel integration project. Using the project created in the previous
section Kernel Configuration for PikeOS, here is how you would do:
you would copy
hello into the directory
target/, rename it
pikeos (as it is the name of the user application as specified
in this project) and use
make boot to link all pieces together:
$ cp hello *<integration project dir>*/target/pikeos $ cd *<integration project dir>* $ source ./PikeOS.sh $ make boot
A file will be created:
this is a PikeOS kernel running your simple Ada application. How to run
it on QEMU will be explained in the next section.
Running an Ada application on PikeOS¶
PikeOS and CODEO are integrated with a simulator called QEMU. This can be a simple way to run and test a PikeOS application.
In the previous sections, we have seen how to create a PikeOS kernel targeted to this simulator, embedding a simple Ada application. make boot should give the proper command to run QEMU.
Debugging an Ada application on PikeOS¶
Any application that should be debugged on PikeOS should call a
init_gdbstub at the early stages of its
execution. To do so with GNAT, the simplest way will be
to recompile the entry code of your Ada application. This entry point is
a file named
p4ext-cert-app.c in the GNAT run-time library; the path to
the GNAT run-time library is given by arm-sysgo-pikeos-gnatls -v.
After copying it in your source directory, you can recompile it with the
$ arm-sysgo-pikeos-gcc -c -DDEBUG p4ext-cert-app.c -I$PIKEOS_TARGET_FILES/include/
Note the presence of an option
-DDEBUG; it enables the gdbstub
hook. After compiling it, you can link it to your application; in the
case of our
hello example, this build command would be:
$ gprbuild --target=arm-sysgo-pikeos --RTS=embedded -f -g hello.adb \ -largs p4ext-cert-app.o -lgdbstub -ldebug
Note that you should also link against
libdebug.a using the options
-lgdbstub -ldebug. You can
then recopy it in the integration project that we created in the
previous sections and relink the kernel:
$ cp hello <integration project dir>/target/pikeos $ cd <integration project dir> $ source ./PikeOS.sh $ make boot
To run this on QEMU, specify several options to
configure the network support properly, using the option
-redir; these options are documented in the usage message of
QEMU that you can get by doing
In our example, the proper set of options would be:
-net nic -net user -redir udp:1500:10.0.2.1:1500
The next step is to launch the host
muxa. Run it in your kernel
integration project (replacing <host> by the actual name of your
$ muxa --type eth --host <host>:1550 --eth-host 0.0.0.0:1501 \ --eth-target <host>:1500
You can then connect to it at <host>:1550 and configure your console and debug channels. For example, to get a console:
$ telnet <host> 1550 Ok: Connected to server. muxa> lsn Ok: Channel list, target supports 16 channels. 0 pikeos/Proc_pikeos/dbg Host:free Port:0 Target:open (Uid:0x000,0x0016,0x0000) 4 Monitor Host:free Port:0 Target:open (Uid:0x000,0x0004,0x0000) 5 mon_con Host:free Port:0 Target:open (Uid:0x000,0x0004,0x0008) 6 traceserver Host:free Port:0 Target:open (Uid:0x000,0x0005,0x0000) muxa> connect mon_con Ok: connected help PikeOS Monitor Command Shell v1.0 Available commands: help Help on command sysinfo Info on system lsp List partition names pinfo Info on a Partition lsc List channels cinfo Info on a channel lsq List Queuing ports of a partition qinfo Info on a queuing port lss List sampling ports of a partition sinfo Info on a sampling port lse List processes of a partition einfo Info on a process lsm List memory requirements of a partition minfo Info on a memory requirement preboot Reboot a Partition phalt Halts a Partition treset Resets the target with the specified mode. kinfo Info on kernel structures ps Show Tasks/Threads
help name to find out more about the command
PikeOS# lsp id name partd fctid lctid mprio mode 1 service 1.5 2 21 102 COLD_START 2 pikeos 1.6 22 22 242 COLD_START PikeOS# pinfo pikeos operating mode: COLD_START num_kpages: 8 free_kpages: 3 flags: 0 max prio: 242 part daemon: 1.6 first child task: 22 last child task: 22 proc count: 1 queuing port count: 0 sampling port count: 0 max. open files: 32 open files: 1 cookie: 0
To connect the application gdbstub to an host port, in order to debug your application:
$ telnet <host> 1550 Ok: Connected to server. muxa> lsn Ok: Channel list, target supports 16 channels. 0 pikeos/Proc_pikeos/dbg Host:free Port:0 Target:open (Uid:0x000,0x0016,0x0000) 4 Monitor Host:free Port:0 Target:open (Uid:0x000,0x0004,0x0000) 5 mon_con Host:connected Port:1550 Target:open (Uid:0x000,0x0004,0x0008) 6 traceserver Host:free Port:0 Target:open (Uid:0x000,0x0005,0x0000) muxa> connect 1551 pikeos/Proc_pikeos/dbg Ok: Connected channel
You can then connect the debugger to <host>:1551 using GDB’s remote protocol, either from GNAT Studio or from the command line:
(gdb) file hello (gdb) target remote <host>:1551 Remote debugging using <host>:1551 0x08011d84 in gdbarch_breakpoint () (gdb) l hello.adb:2 1 with GNAT.IO; use GNAT.IO; 2 3 procedure Hello is 4 begin 5 Put_Line ("Hello from Ada!"); 6 end; (gdb) b 5 Breakpoint 1 at 0x80101da: file hello.adb, line 5. (gdb) c Continuing. Breakpoint 1, hello () at hello.adb:5 5 Put_Line ("Hello from Ada!");
For further information about debugging with GNAT, refer to the GNAT User’s Guide for Native Platforms and to the GDB User’s Manual.