/************************************************************************************************
* arch/arm/src/sam3u/sam3u_vectors.S
* arch/arm/src/chip/sam3u_vectors.S
*
* Copyright (C) 2009-2010 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************************/
/************************************************************************************************
* Included Files
************************************************************************************************/
#include <nuttx/config.h>
#include <arch/irq.h>
/************************************************************************************************
* Preprocessor Definitions
************************************************************************************************/
/* Memory Map:
*
* 0x0800:0000 - Beginning of FLASH. Address of vectors. Mapped to address 0x0000:0000 at boot
* time.
* 0x0803:ffff - End of flash
* 0x2000:0000 - Start of SRAM and start of .data (_sdata)
* - End of .data (_edata) and start of .bss (_sbss)
* - End of .bss (_ebss) and bottom of idle stack
* - _ebss + CONFIG_IDLETHREAD_STACKSIZE = end of idle stack, start of heap. NOTE
* that the ARM uses a decrement before store stack so that the correct initial
* value is the end of the stack + 4;
* 0x2000:bfff - End of SRAM and end of heap
*/
#define IDLE_STACK (_ebss+CONFIG_IDLETHREAD_STACKSIZE)
#define HEAP_BASE (_ebss+CONFIG_IDLETHREAD_STACKSIZE)
/* The Cortex-M3 return from interrupt is unusual. We provide the following special
* address to the BX instruction. The particular value also forces a return to
* thread mode and covers state from the main stack point, the MSP (vs. the MSP).
*/
#define EXC_RETURN 0xfffffff9
/************************************************************************************************
* Global Symbols
************************************************************************************************/
.globl __start
.syntax unified
.thumb
.file "sam3u_vectors.S"
/************************************************************************************************
* Macros
************************************************************************************************/
/* On entry into an IRQ, the hardware automatically saves the xPSR, PC, LR, R12, R0-R3
* registers on the stack, then branches to an instantantiation of the following
* macro. This macro simply loads the IRQ number into R0, then jumps to the common
* IRQ handling logic.
*/
.macro HANDLER, label, irqno
.thumb_func
\label:
mov r0, #\irqno
b sam3u_common
.endm
/************************************************************************************************
* Vectors
************************************************************************************************/
.section .vectors, "ax"
.code 16
.align 2
.globl sam3u_vectors
.type sam3u_vectors, function
sam3u_vectors:
/* Processor Exceptions */
.word IDLE_STACK /* Vector 0: Reset stack pointer */
.word __start /* Vector 1: Reset vector */
.word sam3u_nmi /* Vector 2: Non-Maskable Interrupt (NMI) */
.word sam3u_hardfault /* Vector 3: Hard fault */
.word sam3u_mpu /* Vector 4: Memory management (MPU) */
.word sam3u_busfault /* Vector 5: Bus fault */
.word sam3u_usagefault /* Vector 6: Usage fault */
.word sam3u_reserved /* Vector 7: Reserved */
.word sam3u_reserved /* Vector 8: Reserved */
.word sam3u_reserved /* Vector 9: Reserved */
.word sam3u_reserved /* Vector 10: Reserved */
.word sam3u_svcall /* Vector 11: SVC call */
.word sam3u_dbgmonitor /* Vector 12: Debug monitor */
.word sam3u_reserved /* Vector 13: Reserved */
.word sam3u_pendsv /* Vector 14: Pendable system service request */
.word sam3u_systick /* Vector 15: System tick */
/* External Interrupts */
.word sam3u_supc /* Vector 16+0: Supply Controller */
.word sam3u_rstc /* Vector 16+1: Reset Controller */
.word sam3u_rtc /* Vector 16+2: Real Time Clock */
.word sam3u_rtt /* Vector 16+3: Real Time Timer */
.word sam3u_wdt /* Vector 16+4: Watchdog Timer */
.word sam3u_pmc /* Vector 16+5: Power Management Controller */
.word sam3u_eefc0 /* Vector 16+6: Enhanced Embedded Flash Controller 0 */
.word sam3u_eefc1 /* Vector 16+7: Enhanced Embedded Flash Controller 1 */
.word sam3u_uart /* Vector 16+8: Universal Asynchronous Receiver Transmitter */
.word sam3u_smc /* Vector 16+9: Static Memory Controller */
.word sam3u_pioa /* Vector 16+10: Parallel I/O Controller A */
.word sam3u_piob /* Vector 16+11: Parallel I/O Controller B */
.word sam3u_pioc /* Vector 16+12: Parallel I/O Controller C */
.word sam3u_usart0 /* Vector 16+13: USART 0 */
.word sam3u_usart1 /* Vector 16+14: USART 1 */
.word sam3u_usart2 /* Vector 16+15: USART 2 */
.word sam3u_usart3 /* Vector 16+16: USART 3 */
.word sam3u_hsmci /* Vector 16+17: High Speed Multimedia Card Interface */
.word sam3u_twi0 /* Vector 16+18: Two-Wire Interface 0 */
.word sam3u_twi1 /* Vector 16+19: Two-Wire Interface 1 */
.word sam3u_spi /* Vector 16+20: Serial Peripheral Interface */
.word sam3u_ssc /* Vector 16+21: Synchronous Serial Controller */
.word sam3u_tc0 /* Vector 16+22: Timer Counter 0 */
.word sam3u_tc1 /* Vector 16+23: Timer Counter 1 */
.word sam3u_tc2 /* Vector 16+24: Timer Counter 2 */
.word sam3u_pwm /* Vector 16+25: Pulse Width Modulation Controller */
.word sam3u_adc12b /* Vector 16+26: 12-bit ADC Controller */
.word sam3u_adc /* Vector 16+27: 10-bit ADC Controller */
.word sam3u_dmac /* Vector 16+28: DMA Controller */
.word sam3u_udphs /* Vector 16+29: USB Device High Speed */
.size sam3u_vectors, .-sam3u_vectors
/************************************************************************************************
* .text
************************************************************************************************/
.text
.type handlers, function
.thumb_func
handlers:
HANDLER sam3u_reserved, SAM3U_IRQ_RESERVED /* Unexpected/reserved vector */
HANDLER sam3u_nmi, SAM3U_IRQ_NMI /* Vector 2: Non-Maskable Interrupt (NMI) */
HANDLER sam3u_hardfault, SAM3U_IRQ_HARDFAULT /* Vector 3: Hard fault */
HANDLER sam3u_mpu, SAM3U_IRQ_MEMFAULT /* Vector 4: Memory management (MPU) */
HANDLER sam3u_busfault, SAM3U_IRQ_BUSFAULT /* Vector 5: Bus fault */
HANDLER sam3u_usagefault, SAM3U_IRQ_USAGEFAULT /* Vector 6: Usage fault */
HANDLER sam3u_svcall, SAM3U_IRQ_SVCALL /* Vector 11: SVC call */
HANDLER sam3u_dbgmonitor, SAM3U_IRQ_DBGMONITOR /* Vector 12: Debug Monitor */
HANDLER sam3u_pendsv, SAM3U_IRQ_PENDSV /* Vector 14: Penable system service request */
HANDLER sam3u_systick, SAM3U_IRQ_SYSTICK /* Vector 15: System tick */
HANDLER sam3u_supc, SAM3U_IRQ_SUPC /* Vector 16+0: Supply Controller */
HANDLER sam3u_rstc, SAM3U_IRQ_RSTC /* Vector 16+1: Reset Controller */
HANDLER sam3u_rtc, SAM3U_IRQ_RTC /* Vector 16+2: Real Time Clock */
HANDLER sam3u_rtt, SAM3U_IRQ_RTT /* Vector 16+3: Real Time Timer */
HANDLER sam3u_wdt, SAM3U_IRQ_WDT /* Vector 16+4: Watchdog Timer */
HANDLER sam3u_pmc, SAM3U_IRQ_PMC /* Vector 16+5: Power Management Controller */
HANDLER sam3u_eefc0, SAM3U_IRQ_EEFC0 /* Vector 16+6: Enhanced Embedded Flash Controller 0 */
HANDLER sam3u_eefc1, SAM3U_IRQ_EEFC1 /* Vector 16+7: Enhanced Embedded Flash Controller 1 */
HANDLER sam3u_uart, SAM3U_IRQ_UART /* Vector 16+8: Universal Asynchronous Receiver Transmitter */
HANDLER sam3u_smc, SAM3U_IRQ_SMC /* Vector 16+9: Static Memory Controller */
HANDLER sam3u_pioa, SAM3U_IRQ_PIOA /* Vector 16+10: Parallel I/O Controller A */
HANDLER sam3u_piob, SAM3U_IRQ_PIOB /* Vector 16+11: Parallel I/O Controller B */
HANDLER sam3u_pioc, SAM3U_IRQ_PIOC /* Vector 16+12: Parallel I/O Controller C */
HANDLER sam3u_usart0, SAM3U_IRQ_USART0 /* Vector 16+13: USART 0 */
HANDLER sam3u_usart1, SAM3U_IRQ_USART1 /* Vector 16+14: USART 1 */
HANDLER sam3u_usart2, SAM3U_IRQ_USART2 /* Vector 16+15: USART 2 */
HANDLER sam3u_usart3, SAM3U_IRQ_USART3 /* Vector 16+16: USART 3 */
HANDLER sam3u_hsmci, SAM3U_IRQ_HSMCI /* Vector 16+17: High Speed Multimedia Card Interface */
HANDLER sam3u_twi0, SAM3U_IRQ_TWI0 /* Vector 16+18: Two-Wire Interface 0 */
HANDLER sam3u_twi1, SAM3U_IRQ_TWI1 /* Vector 16+19: Two-Wire Interface 1 */
HANDLER sam3u_spi, SAM3U_IRQ_SPI /* Vector 16+20: Serial Peripheral Interface */
HANDLER sam3u_ssc, SAM3U_IRQ_SSC /* Vector 16+21: Synchronous Serial Controller */
HANDLER sam3u_tc0, SAM3U_IRQ_TC0 /* Vector 16+22: Timer Counter 0 */
HANDLER sam3u_tc1, SAM3U_IRQ_TC1 /* Vector 16+23: Timer Counter 1 */
HANDLER sam3u_tc2, SAM3U_IRQ_TC2 /* Vector 16+24: Timer Counter 2 */
HANDLER sam3u_pwm, SAM3U_IRQ_PWM /* Vector 16+25: Pulse Width Modulation Controller */
HANDLER sam3u_adc12b, SAM3U_IRQ_ADC12B /* Vector 16+26: 12-bit ADC Controller */
HANDLER sam3u_adc, SAM3U_IRQ_ADC /* Vector 16+27: 10-bit ADC Controller */
HANDLER sam3u_dmac, SAM3U_IRQ_DMAC /* Vector 16+28: DMA Controller */
HANDLER sam3u_udphs, SAM3U_IRQ_UDPHS /* Vector 16+29: USB Device High Speed */
/* 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
* REG_R14
* REG_R12
* REG_R3
* REG_R2
* REG_R1
* MSP->REG_R0
*
* And
* R0 contains the IRQ number
* R14 Contains the EXC_RETURN value
* We are in handler mode and the current SP is the MSP
*/
sam3u_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 */
#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
*/
cpsid i /* Disable further interrupts */
/* If CONFIG_ARCH_INTERRUPTSTACK is defined, we will use a special interrupt
* stack pointer. The way that this is done here prohibits nested interrupts!
* Otherwise, we will re-use the main stack for interrupt level processing.
*/
#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 */
#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 */
#endif
/* On return from up_doirq, R0 will hold a pointer to register context
* array to use for the interrupt return. If that return value is the same
* as current stack pointer, then things are relatively easy.
*/
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
* stack but, rather, are within a TCB structure. We'll have to copy some
* 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 */
ldr r1, [r0, #(4*REG_SP)] /* R1=Value of SP before interrupt */
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:
#ifdef CONFIG_NUTTX_KERNEL
ldmia r1!, {r2-r11,r14} /* Recover R4-R11, r14 + 2 temp values */
#else
ldmia r1!, {r2-r11} /* Recover R4-R11 + 2 temp values */
#endif
2:
#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 */
/* 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 */
#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 */
.size handlers, .-handlers
/************************************************************************************************
* Name: up_interruptstack/g_intstackbase
*
* Description:
* Shouldn't happen
*
************************************************************************************************/
#if CONFIG_ARCH_INTERRUPTSTACK > 3
.bss
.global g_intstackbase
.align 4
up_interruptstack:
.skip (CONFIG_ARCH_INTERRUPTSTACK & ~3)
g_intstackbase:
.size up_interruptstack, .-up_interruptstack
#endif
/************************************************************************************************
* .rodata
************************************************************************************************/
.section .rodata, "a"
/* Variables: _sbss is the start of the BSS region (see ld.script) _ebss is the end
* of the BSS regsion (see ld.script). The idle task stack starts at the end of BSS
* and is of size CONFIG_IDLETHREAD_STACKSIZE. The IDLE thread is the thread that
* the system boots on and, eventually, becomes the idle, do nothing task that runs
* only when there is nothing else to run. The heap continues from there until the
* end of memory. See g_heapbase below.
*/
.globl g_heapbase
.type g_heapbase, object
g_heapbase:
.word HEAP_BASE
.size g_heapbase, .-g_heapbase
.end
