ADI GNU Toolchain (bfin-elf) support library for bare-metal C/C++ projects

Main goal is to fix all toolchain lacks for C++ bare-metal applications.

Contents

• Exceptions support.
• PLL/clock management routines.
• C++ constructor call loop support (added "weak" _init() fucntion required by __libc_init_array).
• Several intrinsic functions.

Details

Exceptions support

ADI GNU toolchain does not have code to register exception/interrut hanlders. There are two files added to fix this lack:

• exc.h;
• reg_handler.c

PLL/clock mamagement routines

_pll_set_system_clocks and _pll_set_system_vco from file pwrclk.S

C++ constructor call loop

GNU toolchain uses function __libc_init_array from newlib. The function performs call of low-level function _init() before constructor loop call. But _init() does not exist in toolchain library, so the using of C++ global/static objects (i.e. call of __libc_init_array) causes a link error. To fix this error 'weak' _init() function added to this support library.

Intrinsic functions

ADI GNU toolchain has some built-in functions to support low-level platform-specific features. Unfortunately, not all such functions have been ported from VDSP++. This library contains read_cycles_reg to read processor's CYCLES register.

Besides, ADI GNU toolchain realization of cli/sei built-in functions are erroneous: see bug description https://sourceforge.net/p/adi-toolchain/bugs/69. This library offers replacement for cli/sei built-ins (macros) as inline functions __cli/__sti.