Overview of the native build targets in The native build targets

Symbian OS natively runs on ARM processors. To build code for a phone, a compiler based on the Application Binary Interface (ABI) for the ARM Architecture is needed. This is a standard for the interfaces of binary code running in ARM environments, and is intended to allow inter-operation of binaries produced by different compilers that conform to the standard. The specification is published by ARM at http://www.arm.com/products/DevTools/ABI.html.

The Symbian OS build tools define native build targets that invoke either ARM's RealView Compiler Tools (RVCT), or a suitable version of the GNU Compiler Collection (GCC), known as GCCE. ARM RVCT (http://www.arm.com/products/DevTools/RealViewDevSuite.html) is particularly intended for licensees building ROMs for phones. GCCE is delivered on Symbian OS kits, and is also freely available from http://www.codesourcery.com/.

The situation is complicated by there existing two versions of the ARM ABI, referred to as v1 and v2 respectively. RVCT can be used to build to either ABI version. GCCE can only be used to compile code to v2 of the ARM ABI, not to the earlier v1.

In addition, the toolchain supports building to two versions of the ARM architecture, v5 and v6. See http://www.arm.com/products/CPUs/architecture.html for details of the ARM architectures.

The build targets are intended to generate generic code suitable for execution on processors based on these architectures. The toolchain allows customisation by licensees, for example, in order to target a specific processor more closely: see ARMV5 build customisation.

A summary of the available targets is shown below:

Target name	Instruction set	Compiler	ABI
`ARMV5`	v5	RVCT 2.2	v1
`ARMV5_ABIv2`	v5	RVCT 2.2	v2
`ARMV6`	v6	RVCT 2.2	v1
`ARMV6_ABIv2`	v6	RVCT 2.2	v2
`GCCE`	v5	GCCE	v2

From Symbian OS v9.4 and later, the target names to build a binary conforming to ABIv2 are ARMV5 and ARMV6, and for ABIv1 they are ARMV5_ABIv1 and ARMV6_ABIv1. You can anytime switch back to the old approach as per the above table. For more details, refer to Switching between ABI modes.

For details of these targets, see:

For information on building ROMs using binaries built with these targets, see the Rebuilding Symbian OS reference ROMs section of the ROM building guide.