VfpOemInit (Compact 2013)
10/16/2014
This function initializes support in the OEM adaptation layer (OAL) for vector floating-point (VFP) coprocessors that use the ARM common VFP subarchitecture.
Syntax
void VfpOemInit(
OEMGLOBAL* pOemGlobal,)
DWORD dwFPSID
);
Parameters
- pOemGlobal
Pointer to an OEMGLOBAL structure.
dwFPSID
Either the specific Floating-Point System ID value matching the hardware VFP implementation, or one of the following values:VFP_FULL_EMULATION_FPSID
VFP_AUTO_DETECT_FPSID
See the Remarks section for more information.
Remarks
The OAL uses this function in ARM platforms that have VFP coprocessors. You call this function from OEMInit to initialize the VFP coprocessor on ARM CPUs with this feature.
VfpOemInit uses the default implementations of the functions to turn on the VFP, save and restore the registers, handle exceptions, and query the OAL about VFP hardware. The default implementations are based on the ARM common VFP subarchitecture. If your platform uses a different subarchitecture, you may have to use custom implementations of these functions and call VfpOemInitEx instead of VfpOemInit.The allowed values for dwFPSID are described in the following table.
- <Hardware-specific FPSID>
The specific Floating-Point System ID value matching the hardware VFP implementation. For more information, see the CPU documentation for your hardware.
- VFP_FULL_EMULATION_FPSID
The operating system will emulate VFP support in software. This value should only be used in testing, as software VFP emulation significantly degrades system performance.
- VFP_AUTO_DETECT_FPSID
The operating system will auto-detect hardware VFP features. VFP must be supported in hardware.
The VFP support library (oal_vfp_arm.lib) can be found in the %_OSDESIGNROOT%\%_TGTPLAT%_%TGTCPU%\platcomm\%_TGTPLAT%\lib\%_TGTCPU% directory, under the Debug or Retail subdirectory.
The interface for this library is defined in %_WINCEROOT%\Platform\Common\Src\Arm\Common\Vfp\vfpsupport.h.
For more information about VFP, see the vector floating-point coprocessor technical reference manual for your processor.