.extern uxCriticalNesting\r
.extern pulISRStack\r
\r
- .global vPortFreeRTOSInterruptHandler\r
+ .global _interrupt_handler\r
.global VPortYieldASM\r
- .global vStartFirstTask\r
+ .global vPortStartFirstTask\r
\r
\r
.macro portSAVE_CONTEXT\r
+\r
/* Make room for the context on the stack. */\r
addik r1, r1, -132\r
- /* Save r31 so it can then be used. */\r
+\r
+ /* Save r31 so it can then be used as a temporary. */\r
swi r31, r1, 4\r
+\r
/* Copy the msr into r31 - this is stacked later. */\r
mfs r31, rmsr\r
+\r
/* Stack general registers. */\r
swi r30, r1, 12\r
swi r29, r1, 16\r
swi r4, r1, 116\r
swi r3, r1, 120\r
swi r2, r1, 124\r
+\r
/* Stack the critical section nesting value. */\r
lwi r3, r0, uxCriticalNesting\r
swi r3, r1, 128\r
+\r
/* Save the top of stack value to the TCB. */\r
lwi r3, r0, pxCurrentTCB\r
sw r1, r0, r3\r
.endm\r
\r
.macro portRESTORE_CONTEXT\r
+\r
/* Load the top of stack value from the TCB. */\r
lwi r3, r0, pxCurrentTCB\r
lw r1, r0, r3 \r
+\r
/* Restore the general registers. */\r
lwi r31, r1, 4 \r
lwi r30, r1, 12 \r
lwi r4, r1, 116\r
lwi r2, r1, 124\r
\r
+ /* Reload the rmsr from the stack. */\r
+ lwi r3, r1, 8\r
+ mts rmsr, r3\r
+\r
/* Load the critical nesting value. */\r
lwi r3, r1, 128\r
swi r3, r0, uxCriticalNesting\r
\r
- /* Obtain the MSR value from the stack. */\r
- lwi r3, r1, 8\r
-\r
- /* Are interrupts enabled in the MSR? If so return using an return from \r
- interrupt instruction to ensure interrupts are enabled only once the task\r
- is running again. */\r
- andi r3, r3, 2\r
- beqid r3, 36\r
- or r0, r0, r0\r
+ /* Test the critical nesting value. If it is non zero then the task last\r
+ exited the running state using a yield. If it is zero, then the task\r
+ last exited the running state through an interrupt. */\r
+ xori r3, r3, 0\r
+ bnei r3, exit_from_yield\r
\r
- /* Reload the rmsr from the stack, clear the enable interrupt bit in the\r
- value before saving back to rmsr register, then return enabling interrupts\r
- as we return. */\r
- lwi r3, r1, 8\r
- andi r3, r3, ~2\r
- mts rmsr, r3\r
+ /* r3 was being used as a temporary. Now restore its true value from the\r
+ stack. */\r
lwi r3, r1, 120\r
+\r
+ /* Remove the stack frame. */\r
addik r1, r1, 132\r
+\r
+ /* Return using rtid so interrupts are re-enabled as this function is\r
+ exited. */\r
rtid r14, 0\r
or r0, r0, r0\r
\r
- /* Reload the rmsr from the stack, place it in the rmsr register, and\r
- return without enabling interrupts. */\r
- lwi r3, r1, 8\r
- mts rmsr, r3\r
+ .endm\r
+\r
+ .text\r
+ .align 2\r
+\r
+/* This function is used to exit portRESTORE_CONTEXT() if the task being\r
+returned to last left the Running state by calling taskYIELD() (rather than\r
+being preempted by an interrupt. */\r
+exit_from_yield:\r
+\r
+ /* r3 was being used as a temporary. Now restore its true value from the\r
+ stack. */\r
lwi r3, r1, 120\r
+\r
+ /* Remove the stack frame. */\r
addik r1, r1, 132\r
+\r
+ /* Return to the task. */\r
rtsd r14, 0\r
or r0, r0, r0\r
\r
- .endm\r
\r
- .text\r
- .align 2\r
+_interrupt_handler:\r
\r
-\r
-vPortFreeRTOSInterruptHandler:\r
portSAVE_CONTEXT\r
- /* Entered via an interrupt so interrupts must be enabled in msr. */\r
- ori r31, r31, 2\r
+\r
/* Stack msr. */\r
swi r31, r1, 8\r
- /* Stack the return address. As we entered via an interrupt we do\r
- not need to modify the return address prior to stacking. */\r
+\r
+ /* Stack the return address. */\r
swi r14, r1, 76\r
- /* Now switch to use the ISR stack. */\r
- lwi r3, r0, pulISRStack\r
- add r1, r3, r0\r
+\r
+ /* Switch to the ISR stack. */\r
+ lwi r1, r0, pulISRStack\r
+\r
+ /* Execute any pending interrupts. */\r
bralid r15, XIntc_DeviceInterruptHandler\r
or r0, r0, r0\r
+\r
+ /* Restore the context of the next task scheduled to execute. */\r
portRESTORE_CONTEXT\r
\r
\r
VPortYieldASM:\r
+\r
portSAVE_CONTEXT\r
+\r
/* Stack msr. */\r
swi r31, r1, 8\r
- /* Modify the return address so we return to the instruction after the\r
- exception. */\r
+\r
+ /* Modify the return address so a return is done to the instruction after\r
+ the call to VPortYieldASM. */\r
addi r14, r14, 8\r
swi r14, r1, 76\r
- /* Now switch to use the ISR stack. */\r
- lwi r3, r0, pulISRStack\r
- add r1, r3, r0\r
+\r
+ /* Switch to use the ISR stack. */\r
+ lwi r1, r0, pulISRStack\r
+\r
+ /* Select the next task to execute. */\r
bralid r15, vTaskSwitchContext\r
or r0, r0, r0\r
+\r
+ /* Restore the context of the next task scheduled to execute. */\r
portRESTORE_CONTEXT\r
\r
-vStartFirstTask:\r
+vPortStartFirstTask:\r
+\r
portRESTORE_CONTEXT\r
\r
\r