int up_svcall(int irq, FAR void *context)
{
uint32_t *regs = (uint32_t*)context;
DEBUGASSERT(regs && regs == current_regs);
/* The SVCall software interrupt is called with R0 = system call command
* and R1..R7 = variable number of arguments depending on the system call.
*/
svcdbg("SVCALL Entry: regs: %p cmd: %d\n", regs, regs[REG_R0]);
svcdbg(" R0: %08x %08x %08x %08x %08x %08x %08x %08x\n",
regs[REG_R0], regs[REG_R1], regs[REG_R2], regs[REG_R3],
regs[REG_R4], regs[REG_R5], regs[REG_R6], regs[REG_R7]);
svcdbg(" R8: %08x %08x %08x %08x %08x %08x %08x %08x\n",
regs[REG_R8], regs[REG_R9], regs[REG_R10], regs[REG_R11],
regs[REG_R12], regs[REG_R13], regs[REG_R14], regs[REG_R15]);
svcdbg(" PSR=%08x\n", regs[REG_XPSR]);
/* Handle the SVCall according to the command in R0 */
switch (regs[REG_R0])
{
/* R0=SYS_save_context: This is a save context command:
*
* int up_saveusercontext(uint32_t *saveregs);
*
* At this point, the following values are saved in context:
*
* R0 = SYS_save_context
* R1 = saveregs
*
* In this case, we simply need to copy the current regsters to the
* save register space references in the saved R1 and return.
*/
case SYS_save_context:
{
DEBUGASSERT(regs[REG_R1] != 0);
memcpy((uint32_t*)regs[REG_R1], regs, XCPTCONTEXT_SIZE);
}
break;
/* R0=SYS_restore_context: This a restore context command:
*
* void up_fullcontextrestore(uint32_t *restoreregs) __attribute__ ((noreturn));
*
* At this point, the following values are saved in context:
*
* R0 = SYS_restore_context
* R1 = restoreregs
*
* In this case, we simply need to set current_regs to restore register
* area referenced in the saved R1. context == current_regs is the normal
* exception return. By setting current_regs = context[R1], we force
* the return to the saved context referenced in R1.
*/
case SYS_restore_context:
{
DEBUGASSERT(regs[REG_R1] != 0);
current_regs = (uint32_t*)regs[REG_R1];
}
break;
/* R0=SYS_switch_context: This a switch context command:
*
* void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
*
* At this point, the following values are saved in context:
*
* R0 = 1
* R1 = saveregs
* R2 = restoreregs
*
* In this case, we do both: We save the context registers to the save
* register area reference by the saved contents of R1 and then set
* current_regs to to the save register area referenced by the saved
* contents of R2.
*/
case SYS_switch_context:
{
DEBUGASSERT(regs[REG_R1] != 0 && regs[REG_R2] != 0);
memcpy((uint32_t*)regs[REG_R1], regs, XCPTCONTEXT_SIZE);
current_regs = (uint32_t*)regs[REG_R2];
}
break;
/* This is not an architecture-specific system call. If NuttX is built
* as a standalone kernel with a system call interface, then all of the
* additional system calls must be handled as in the default case.
*/
default:
#ifdef CONFIG_NUTTX_KERNEL
dispatch_syscall(regs);
#else
slldbg("ERROR: Bad SYS call: %d\n", regs[REG_R0]);
#endif
break;
}
/* Report what happened. That might difficult in the case of a context switch */
if (regs != current_regs)
{
svcdbg("SVCall Return: Context switch!\n");
svcdbg(" R0: %08x %08x %08x %08x %08x %08x %08x %08x\n",
current_regs[REG_R0], current_regs[REG_R1], current_regs[REG_R2], current_regs[REG_R3],
current_regs[REG_R4], current_regs[REG_R5], current_regs[REG_R6], current_regs[REG_R7]);
svcdbg(" R8: %08x %08x %08x %08x %08x %08x %08x %08x\n",
current_regs[REG_R8], current_regs[REG_R9], current_regs[REG_R10], current_regs[REG_R11],
current_regs[REG_R12], current_regs[REG_R13], current_regs[REG_R14], current_regs[REG_R15]);
svcdbg(" PSR=%08x\n", current_regs[REG_XPSR]);
}
else
{
svcdbg("SVCall Return: %d\n", regs[REG_R0]);
}
return OK;
}
int up_swint0(int irq, FAR void *context)
{
uint32_t *regs = (uint32_t*)context;
DEBUGASSERT(regs && regs == current_regs);
/* Software interrupt 0 is invoked with REG_A0 (REG_R4) = system call
* command and REG_A1-3 and REG_T0-2 (REG_R5-10) = variable number of
* arguments depending on the system call.
*/
#ifdef DEBUG_SWINT0
swidbg("Entry: regs: %p cmd: %d\n", regs, regs[REG_R4]);
up_registerdump(regs);
#endif
/* Handle the SWInt according to the command in $4 */
switch (regs[REG_R4])
{
/* R4=SYS_restore_context: This a restore context command:
*
* void up_fullcontextrestore(uint32_t *restoreregs) __attribute__ ((noreturn));
*
* At this point, the following values are saved in context:
*
* R4 = SYS_restore_context
* R5 = restoreregs
*
* In this case, we simply need to set current_regs to restore register
* area referenced in the saved R1. context == current_regs is the normal
* exception return. By setting current_regs = context[R1], we force
* the return to the saved context referenced in R1.
*/
case SYS_restore_context:
{
DEBUGASSERT(regs[REG_A1] != 0);
current_regs = (uint32_t*)regs[REG_A1];
}
break;
/* R4=SYS_switch_context: This a switch context command:
*
* void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
*
* At this point, the following values are saved in context:
*
* R4 = SYS_switch_context
* R5 = saveregs
* R6 = restoreregs
*
* In this case, we save the context registers to the save register
* area reference by the saved contents of R5 and then set
* current_regs to to the save register area referenced by the saved
* contents of R6.
*/
case SYS_switch_context:
{
DEBUGASSERT(regs[REG_A1] != 0 && regs[REG_A2] != 0);
up_copystate((uint32_t*)regs[REG_A1], regs);
current_regs = (uint32_t*)regs[REG_A2];
}
break;
/* This is not an architecture-specify system call. If NuttX is built
* as a standalone kernel with a system call interface, then all of the
* additional system calls must be handled as in the default case.
*/
default:
#ifdef CONFIG_NUTTX_KERNEL
dispatch_syscall(regs);
#else
slldbg("ERROR: Bad SYS call: %d\n", regs[REG_A0]);
#endif
break;
}
/* Report what happened. That might difficult in the case of a context switch */
#ifdef DEBUG_SWINT0
if (regs != current_regs)
{
swidbg("SWInt Return: Context switch!\n");
up_registerdump(current_regs);
}
else
{
swidbg("SWInt Return: %d\n", regs[REG_V0]);
}
#endif
/* Clear the pending software interrupt 0 */
up_clrpend_irq(PIC32MX_IRQSRC_CS0);
return OK;
}
