diff options
| -rw-r--r-- | cpukit/score/cpu/sparc/cpu_asm.S | 29 | ||||
| -rw-r--r-- | cpukit/score/cpu/sparc/include/rtems/score/cpu.h | 19 |
2 files changed, 47 insertions, 1 deletions
diff --git a/cpukit/score/cpu/sparc/cpu_asm.S b/cpukit/score/cpu/sparc/cpu_asm.S index 287c2c4cd9..fd7186b499 100644 --- a/cpukit/score/cpu/sparc/cpu_asm.S +++ b/cpukit/score/cpu/sparc/cpu_asm.S @@ -246,6 +246,14 @@ done_flushing: mov %g1, %psr ! restore status register and ! **** ENABLE TRAPS **** + /* + * WARNING: This code does not run with the restored stack pointer. In + * SMP configurations, it uses a processor-specific stack. In + * uniprocessor configurations, it uses the stack of the caller. In + * this case, the caller shall ensure that it is not the interrupt + * stack (which is also the system initialization stack). + */ + ld [%o1 + G5_OFFSET], %g5 ! restore the global registers ld [%o1 + G7_OFFSET], %g7 @@ -266,7 +274,9 @@ done_flushing: ldd [%o1 + I4_OFFSET], %i4 ldd [%o1 + I6_FP_OFFSET], %i6 - ldd [%o1 + O6_SP_OFFSET], %o6 ! restore the output registers + ldd [%o1 + O6_SP_OFFSET], %o6 ! restore the non-volatile output + ! registers (stack pointer, + ! link register) jmp %o7 + 8 ! return nop ! delay slot @@ -325,6 +335,23 @@ SYM(_CPU_Context_restore): ba SYM(_CPU_Context_restore_heir) mov %i0, %o1 ! in the delay slot +#if !defined(RTEMS_SMP) + .align 4 + PUBLIC(_SPARC_Start_multitasking) +SYM(_SPARC_Start_multitasking): + /* + * Restore the stack pointer right now, so that the window flushing and + * interrupts during _CPU_Context_restore_heir() use the stack of the + * heir thread. This is crucial for the interrupt handling to prevent + * a concurrent use of the interrupt stack (which is also the system + * initialization stack). + */ + ld [%o0 + O6_SP_OFFSET], %o6 + + ba SYM(_CPU_Context_restore) + nop +#endif + /* * void _SPARC_Interrupt_trap() * diff --git a/cpukit/score/cpu/sparc/include/rtems/score/cpu.h b/cpukit/score/cpu/sparc/include/rtems/score/cpu.h index 2021b108db..a21cef371f 100644 --- a/cpukit/score/cpu/sparc/include/rtems/score/cpu.h +++ b/cpukit/score/cpu/sparc/include/rtems/score/cpu.h @@ -993,6 +993,25 @@ RTEMS_NO_RETURN void _CPU_Context_switch_no_return( */ RTEMS_NO_RETURN void _CPU_Context_restore( Context_Control *new_context ); +#if !defined(RTEMS_SMP) +/** + * @brief Starts multitasking in uniprocessor configurations. + * + * This function just sets the stack of the heir thread and then calls + * _CPU_Context_restore(). + * + * This is causes that the window flushing and interrupts during + * _CPU_Context_restore() use the stack of the heir thread. This is crucial + * for the interrupt handling to prevent a concurrent use of the interrupt + * stack (which is also the system initialization stack). + * + * @param[in] heir is the context of the heir thread. + */ +RTEMS_NO_RETURN void _SPARC_Start_multitasking( Context_Control *heir ); + +#define _CPU_Start_multitasking( _heir ) _SPARC_Start_multitasking( _heir ) +#endif + #if defined(RTEMS_SMP) uint32_t _CPU_SMP_Initialize( void ); |