[Bug 1001153] New: HAL_DISABLE_INTERRUPTS not working as expected

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           Summary: HAL_DISABLE_INTERRUPTS not working as expected
           Product: eCos
           Version: CVS
          Platform: stm32e_eval (ST STM3210E EVAL board)
        OS/Version: Cortex-M
            Status: UNCONFIRMED
          Severity: critical
          Priority: low
         Component: HAL
        AssignedTo: unassigned@bugs.ecos.sourceware.org
        ReportedBy: uholeschak@bihl-wiedemann.de
                CC: ecos-bugs@ecos.sourceware.org
             Class: Advice Request


The macro

# define HAL_DISABLE_INTERRUPTS(__old)          \
    __asm__ volatile (                          \
        "mrs    %0, basepri             \n"     \
        "mov    r1,%1                   \n"     \
        "msr    basepri,r1              \n"     \
        : "=r" (__old)                          \
        :  "r" (CYGNUM_HAL_CORTEXM_PRIORITY_MAX)\
        : "r1"                                  \
        );

is not working as expected if the compiler uses the same register for input and
output argument. In this case the basepri is not modified because the input
register is overwritten with the old basepri value before the assignment.
The following modification fixes this problem:

# define HAL_DISABLE_INTERRUPTS(__old)          \
    __asm__ volatile (                          \
        "mrs    r2, basepri             \n"     \
        "mov    r1,%1                   \n"     \
        "msr    basepri,r1              \n"     \
        "mov    %0, r2                  \n"     \
        : "=r" (__old)                             \
        :  "r" (CYGNUM_HAL_CORTEXM_PRIORITY_MAX)\
        : "r1", "r2"                            \
        );

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