Building an SDA PIC/PID Application

To build a SDA PIC/PID application, select SDA PIC/PID in the ABI list box in the CodeWarrior IDE's EPPC Target target preferences Properties > C/C++ Build > Settings > Tool Settings > PowerPC CPU panel. The compiler defines a simple variable that we can use to guard PIC/PID source.

#if __option(sda_pic_pid) // is true if we have chosen SDA 
  PIC/PID ABI
  

At link-time, the linker generates a table used for the runtime files __ppc_eabi_init.cpp and __ppc_eabi_init.c .

If our application contains absolute addressing relocations, we will receive linker warnings telling us that those relocations may cause a problem. To resolve these warnings, either:

• change the Code Model listbox in the CodeWarrior IDE's EPPC Target target preferences Properties > C/C++ Build > Settings > Tool Settings > PowerPC CPU panel to be SDA Based PIC/PID Addressing for all of our sources and libraries
• check the Tune Relocations checkbox in the EPPC Target target preferences Properties > C/C++ Build > Settings > Tool Settings > PowerPC CPU panel. This new option is only available for the EABI and SDA PIC/PID ABIs. For EABI, it changes 14-bit branch relocations to 24-bit branch relocations, but only if they can not reach the calling site from the original relocation.

  For SDA PIC/PID, this option changes absolute-addressed references of data from code to use a small data register instead of r0 and changes absolute code-to-code references to use the PC-relative relocations.

• Linking Assembly Files
  It is always possible to link in an assembly file that does not behave in a standard way.
• Modifications to the Section Pragma
  The pragma #pragma section has been modified to accept far_sda_rel for the data_mode and code_mode options, even if we are not using Code Model SDA Based PIC/PID Addressing.