Specific Build Information

Building device drivers

Building a device driver is similar to building any other component in Symbian platform. This section discusses the details that are specific to drivers, and assumes that you are familiar with the Symbian platform build tools.

Device drivers can be built either by using console commands (bldmake and abld) or by using an IDE. Any project can be built for multiple platforms. Generally, it is either ARM for the hardware target or WINSCW for the emulator target. For hardware target builds, the build can be for ARMV5, ARMV6, and Thumb, while for emulator builds, the platform is WINSCW. The compilers used for ARM are the ARM RVCT compiler or, in earlier versions of the platform, a version of the GNU GCC compiler. For the emulator, the compiler is the Carbide.c++ or Metrowerks CodeWarrior compiler.

The .mmp file (project file) specifies the source files to build and the platform for which the target binary will be built.

Variant specific target

When a target is specified using the keyword VariantTarget(), the build tools generate a unique name for the binary by adding the variant name. This allows separate binaries to be created for each variant, and prevents the current binary being overwritten.

For example, if the target to be built is d_expio_ldd.ldd, then VariantTarget(d_expio_ldd,ldd) would be specified in the .mmp file. If the project is then built for the h4hrp variant, the final target binary built is called _h4hrp_d_expio_ldd.ldd.

ROM image build

To include a driver in a ROM image, the driver's files must be included in the corresponding obey files (.oby). In the base subsystem, the binaries are specified in .iby files, and the .iby files are then included in .oby files.

For example, to include a driver in the H4 text shell ROM image, it should be included in kernel.iby. This file is located in base\omap_hrp\h4\rom\, and exported to epoc32\rom\h4hrp. Similarly for the TechView ROM build, the relevant file is base_h4hrp.iby file, which is located in base\omap_hrp_h4\rom\, and exported to epoc32\rom\include. An example from an .iby file is shown below:

// .iby file

/**
##KMAIN## gets the path for e32
##BUILD## gets the build – udeb/urel according to build
##VARIANT gets the target from corresponding variant  
*/

device[VARID]=\EPOC32\RELEASE\##KMAIN##\##BUILD##\d_expio_ldd.ldd sys\bin\d_expio_ldd.ldd 

device[VARID]=\EPOC32\RELEASE\##KMAIN##\##BUILD##\_##VARIANT##_d_expio_pdd.pdd sys\bin\d_expio_pdd.pdd

On building the test .inf files, test .iby files will be generated. This includes the newly added binaries in the .iby file.

After building the drivers, a ROM can be built. Device driver and base developers generally build text shell ROM images for development and testing. These can be built using the rom tool (from base\e32\rombuild). By default, the ROM image is generated in that directory. An alternate path can also be specified.

For example, for the H4HRP variant, a text shell ROM image is built using:

rom –v=h4hrp –I=armv5 udeb

This builds a ROM called H4HRPARMV5D.IMG, which can then be downloaded to target hardware and tested.

To include base test programs in a ROM image, the option –type can be used. For example:

rom –v=h4hrp –I=armv5 udeb –type=e32tests

This includes the tests from base\e32test. The tool uses as input a generated or precompiled oby file, which includes all the generated test .iby files.