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Compiler-specific Features
The __disable_fiq intrinsic can only be executed in privileged modes, that is, in non
user modes. In User mode this intrinsic does not change the interrupt flags in the CPSR.
Example
void foo(void)
{
int was_masked = __disable_fiq();
/* ... */
if (!was_masked)
__enable_fiq();
}
See also
• __enable_fiq on page 4-82.
4.7.8 __disable_irq
This intrinsic disables IRQ interrupts.
Note
Typically, this intrinsic disables IRQ interrupts by setting the I-bit in the CPSR.
However, for M-profile it sets the exception mask register (PRIMASK).
Syntax
int __disable_irq(void);
void __disable_irq(void);
Usage
The function prototype to use for this intrinsic depends on the target architecture you
are compiling for. For ARMv7 (--cpu=7), use void __disable_irq(void);. For all other
architectures, including ARMv7-A, ARMv7-R, and ARMv7-M, you can use
int __disable_irq(void); or void __disable_irq(void);.
Return value
int __disable_irq(void); returns the value the IRQ interrupt mask has in the PSR prior
to the disabling of IRQ interrupts.
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