diff options
Diffstat (limited to 'nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S')
| -rwxr-xr-x | nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S | 93 |
1 files changed, 68 insertions, 25 deletions
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S b/nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S index 7a25c5610..4cfa9a3ce 100755 --- a/nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S +++ b/nuttx/arch/arm/src/lpc17xx/lpc17_vectors.S @@ -220,7 +220,8 @@ handlers: HANDLER lpc17_usbact, LPC17_IRQ_USBACT /* Vector 16+33: USB Activity Interrupt */ HANDLER lpc17_canact, LPC17_IRQ_CANACT /* Vector 16+34: CAN Activity Interrupt */ -/* Common IRQ handling logic. On entry here, the stack is like the following: +/* Common IRQ handling logic. On entry here, the return stack is on either + * the PSP or the MSP and looks like the following: * * REG_XPSR * REG_R15 @@ -231,18 +232,38 @@ handlers: * REG_R1 * MSP->REG_R0 * - * and R0 contains the IRQ number + * And + * R0 contains the IRQ number + * R14 Contains the EXC_RETURN value + * We are in handler mode and the current SP is the MSP */ lpc17_common: /* Complete the context save */ +#ifdef CONFIG_NUTTX_KERNEL + /* The EXC_RETURN value will be 0xfffffff9 (privileged thread) or 0xfffffff1 + * (handler mode) if the state is on the MSP. It can only be on the PSP if + * EXC_RETURN is 0xfffffffd (unprivileged thread) + */ + + adds r2, r14, #3 /* If R14=0xfffffffd, then r2 == 0 */ + ite ne /* Next two instructions are condition */ + mrsne r1, msp /* R1=The main stack pointer */ + mrseq r1, psp /* R1=The process stack pointer */ +#else mrs r1, msp /* R1=The main stack pointer */ - mov r2, r1 /* R2=Copy of the main stack pointer */ - add r2, #HW_XCPT_SIZE /* R2=MSP before the interrupt was taken */ +#endif + + mov r2, r1 /* R2=Copy of the main/process stack pointer */ + add r2, #HW_XCPT_SIZE /* R2=MSP/PSP before the interrupt was taken */ mrs r3, primask /* R3=Current PRIMASK setting */ +#ifdef CONFIG_NUTTX_KERNEL + stmdb r1!, {r2-r11,r14} /* Save the remaining registers plus the SP value */ +#else stmdb r1!, {r2-r11} /* Save the remaining registers plus the SP value */ +#endif /* Disable interrupts, select the stack to use for interrupt handling * and call up_doirq to handle the interrupt @@ -257,13 +278,13 @@ lpc17_common: #if CONFIG_ARCH_INTERRUPTSTACK > 3 ldr sp, =g_intstackbase - str r1, [sp, #-4]! /* Save the MSP on the interrupt stack */ - bl up_doirq /* R0=IRQ, R1=register save (msp) */ - ldr r1, [sp, #+4]! /* Recover R1=main stack pointer */ + str r1, [sp, #-4]! /* Save the MSP on the interrupt stack */ + bl up_doirq /* R0=IRQ, R1=register save (msp) */ + ldr r1, [sp, #+4]! /* Recover R1=main stack pointer */ #else - mov sp, r1 /* We are using the main stack pointer */ - bl up_doirq /* R0=IRQ, R1=register save (msp) */ - mov r1, sp /* Recover R1=main stack pointer */ + mov sp, r1 /* We are using the main stack pointer */ + bl up_doirq /* R0=IRQ, R1=register save (msp) */ + mov r1, sp /* Recover R1=main stack pointer */ #endif /* On return from up_doirq, R0 will hold a pointer to register context @@ -271,8 +292,8 @@ lpc17_common: * as current stack pointer, then things are relatively easy. */ - cmp r0, r1 /* Context switch? */ - beq 1f /* Branch if no context switch */ + cmp r0, r1 /* Context switch? */ + beq 1f /* Branch if no context switch */ /* We are returning with a pending context switch. This case is different * because in this case, the register save structure does not lie on the @@ -280,34 +301,56 @@ lpc17_common: * values to the stack. */ - add r1, r0, #SW_XCPT_SIZE /* R1=Address of HW save area in reg array */ - ldmia r1, {r4-r11} /* Fetch eight registers in HW save area */ + add r1, r0, #SW_XCPT_SIZE /* R1=Address of HW save area in reg array */ + ldmia r1, {r4-r11} /* Fetch eight registers in HW save area */ ldr r1, [r0, #(4*REG_SP)] /* R1=Value of SP before interrupt */ - stmdb r1!, {r4-r11} /* Store eight registers in HW save area */ - ldmia r0, {r2-r11} /* Recover R4-R11 + 2 temp values */ - b 2f /* Re-join common logic */ + stmdb r1!, {r4-r11} /* Store eight registers in HW save area */ +#ifdef CONFIG_NUTTX_KERNEL + ldmia r0, {r2-r11,r14} /* Recover R4-R11, r14 + 2 temp values */ +#else + ldmia r0, {r2-r11} /* Recover R4-R11 + 2 temp values */ +#endif + b 2f /* Re-join common logic */ /* We are returning with no context switch. We simply need to "unwind" * the same stack frame that we created */ 1: - ldmia r1!, {r2-r11} /* Recover R4-R11 + 2 temp values */ +#ifdef CONFIG_NUTTX_KERNEL + ldmia r0, {r2-r11,r14} /* Recover R4-R11, r14 + 2 temp values */ +#else + ldmia r0, {r2-r11} /* Recover R4-R11 + 2 temp values */ +#endif 2: - msr msp, r1 /* Recover the return MSP value */ +#ifdef CONFIG_NUTTX_KERNEL + /* The EXC_RETURN value will be 0xfffffff9 (privileged thread) or 0xfffffff1 + * (handler mode) if the state is on the MSP. It can only be on the PSP if + * EXC_RETURN is 0xfffffffd (unprivileged thread) + */ + + adds r0, r14, #3 /* If R14=0xfffffffd, then r0 == 0 */ + ite ne /* Next two instructions are condition */ + msrne msp, r1 /* R1=The main stack pointer */ + msreq psp, r1 /* R1=The process stack pointer */ +#else + msr msp, r1 /* Recover the return MSP value */ - /* Restore the interrupt state. Preload r14 with the special return - * value first (so that the return actually occurs with interrupts - * still disabled). + /* Preload r14 with the special return value first (so that the return + * actually occurs with interrupts still disabled). */ - ldr r14, =EXC_RETURN /* Load the special value */ - msr primask, r3 /* Restore interrupts */ + ldr r14, =EXC_RETURN /* Load the special value */ +#endif + + /* Restore the interrupt state */ + + msr primask, r3 /* Restore interrupts */ /* Always return with R14 containing the special value that will: (1) * return to thread mode, and (2) continue to use the MSP */ - bx r14 /* And return */ + bx r14 /* And return */ .size handlers, .-handlers /************************************************************************************************ |