Introduction¶
About GNATemulator¶
Simulators are useful tools in many respects. Installation, setup and deployment to a development team will prove to be easier and quicker than with a real target. Simulator usage on a native platform will also bring more flexibility in the development of the application.
GNATemulator is particularly suited for functional testing and unit testing. The product comes with a complete simulation environment and related BSP for non bareboard systems such as VxWorks 653. It allows for efficient target code execution. It simulates a simple board and does not aim at complete board simulation. This should be mostly transparent to the application developer as the differences between the real target and the simulator should be handled and hidden by the platform provider.
Product Content¶
The product contains four components:
- The Simulator: This is the heart of the product. The main tool is called
gnatemu
and is prefixed by the relevant target name. Under the hood it relies on the QEMU processor and board simulator. GNATemulator efficiently runs the executable: the target code is translated on the fly, one basic block at a time, to the host processor. The translated code is then kept in a cache so that no new translation is required when the execution passes through a basic block that has been executed. An important point to keep in mind is that GNATemulator is translating and executing instructions as fast as possible and thus won’t be cycle accurate. The clock used by GNATemulator is the host system clock. Timing events are thus dependent on that clock and will not reflect the timing characteristics of a real target board.- The BSP: On non-bareboard systems, a BSP is provided when necessary. This is the case for example on VxWorks 653. On that target we provide a BSP called
qemu
that should be installed in the VxWorks 653 installation. The BSP simulates a board with one UART (serial link), one ethernet controller, a timer, ROM and 128MB of RAM.- GNAT Bus: A native framework to emulate devices (see Extending GNATemulator chapter).
- The examples: For each supported platform there are examples that can be used as a reference for further development with GNATemulator
Note on the Documentation¶
As mentioned in the previous section the main tool name is:
<target>-gnatemu
Along this documentation, in the sections that are not target specific we will
use gnatemu
for the tool name, skipping the target prefix. In that
cases always replace gnatemu
by <target>-gnatemu
where
<target>
is the relevant target prefix for your context.
As a reminder here is the list of target supported by GNATemulator along with the expected tool name:
Platform | Tool name |
---|---|
PowerPC e500v2 VxWorks 6.x | e500v2-wrs-vxworks-gnatemu |
PowerPC VxWorks 6.x | powerpc-wrs-vxworks-gnatemu |
PowerPC VxWorks 653 | powerpc-wrs-vxworksae-gnatemu |
PowerPC ELF | powerpc-elf-gnatemu |
PowerPC 55xx and e500v2 ELF | powerpc-eabispe-gnatemu |
LEON 2 ELF | leon-elf-gnatemu |
LEON 3 ELF | leon3-elf-gnatemu |
ARM ELF | arm-eabi-gnatemu |
AARCH64 ELF | aarch64-elf-gnatemu |