ST STM32F4 Series Programming Manual page 258

Core peripherals
fpscr_val = *(uint32_t*)sp;
{ check exception flags }
fpscr_val &= (uint32_t)~0x8F ;
*(uint32_t*)sp = fpscr_val;
__DMB() ;
}
// FPU IRQ Handler
void __asm FPU_IRQHandler(void)
{
IMPORT
MOV
MOV
VMRS R2, FPSCR
B
BX
}
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sp = sp + 0x60;
}
else if(lr == 0xFFFFFFED)
{
sp = __get_PSP() + 0x60 ;
}
FPU_ExceptionHandler
R0, LR
R1, SP
FPU_ExceptionHandler
LR
DocID022708 Rev 6
// Clear all exception flags
// move LR to R0
// Save SP to R1 to avoid any modification to
// the stack pointer from FPU_ExceptionHandler
// dummy read access, to force clear
PM0214