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Add basic context switching logic

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1777 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2009-05-13 19:53:16 +00:00
parent 2827157b5f
commit b0211916c7
6 changed files with 287 additions and 13 deletions
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6
arch/arm/src/lm3s/Make.defs
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@ -45,9 +45,9 @@ CMN_CSRCS = up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
up_sigdeliver.c up_syscall.c up_unblocktask.c \
up_undefinedinsn.c up_usestack.c
CHIP_ASRCS =
CHIP_CSRCS = lm3s_start.c lm3s_syscontrol.c lm3s_irq.c lm3s_timerisr.c \
lm3s_lowputc.c lm3s_serial.c
CHIP_ASRCS = lm3s_context.S
CHIP_CSRCS = lm3s_start.c lm3s_syscontrol.c lm3s_irq.c lm3s_pendsv.c \
lm3s_timerisr.c lm3s_lowputc.c lm3s_serial.c
ifdef CONFIG_NET
CHIP_CSRCS += lm3s_ethernet.c

145
arch/arm/src/lm3s/lm3s_context.S Normal file
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@ -0,0 +1,145 @@
/************************************************************************************
* arch/arm/src/lm3s/lm3s_context.S
* arch/arm/src/chip/lm3s_context.S
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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>
#include "cortexm3_nvic.h"
/************************************************************************************
* Preprocessor Definitions
************************************************************************************/
/************************************************************************************
* Global Symbols
************************************************************************************/
.syntax unified
.thumb
.file "lm3s_context.S"
/************************************************************************************
* Macros
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
/**************************************************************************
* Name: up_saveusercontext
*
* Description:
* Save the current thread context. Full prototype is:
*
* int up_saveusercontext(uint32 *regs);
*
* Return:
* 0: Normal return
* 1: Context switch return
*
**************************************************************************/
.text
.thumb_func
.globl up_saveusercontext
.type up_saveusercontext, function
up_saveusercontext:
/* Perform the System call with R0=0 and R1=regs */
ldr r2, nvic_intctrl /* R2: Address NVIC INTCTRL registers */
ldr r3, [r2, #0] /* R3: Contentx of NVIC INCTRL */
orr r3, r3, #NVIC_INTCTRL_PENDSVSET
mov r1, r0 /* R1: regs */
mov r0, #0 /* R0: 0 means save context (also return value) */
str r3, [r2, #0] /* Force Pend SV */
/* There are two return conditions. On the first return, R0 (the
* return value will be zero. On the second return we need to
* force R0 to be 1.
*/
add r2, r1, #(4*REG_R0)
mov r3, #1
str r3, [r2, #0]
bx lr /* "normal" return with r0=0 or
* context switch with r0=1 */
.size up_saveusercontext, .-up_saveusercontext
/**************************************************************************
* Name: up_fullcontextrestore
*
* Description:
* Restore the current thread context. Full prototype is:
*
* void up_fullcontextrestore(uint32 *regs) __attribute__ ((noreturn));
*
* Return:
* None
*
**************************************************************************/
.thumb_func
.globl up_fullcontextrestore
.type up_fullcontextrestore, function
up_fullcontextrestore:
/* Perform the System call with R0=1 and R1=regs */
ldr r2, nvic_intctrl /* R2: Address NVIC INTCTRL registers */
ldr r3, [r2, #0] /* R3: Contentx of NVIC INCTRL */
orr r3, r3, #NVIC_INTCTRL_PENDSVSET
mov r1, r0 /* R1: regs */
mov r0, #1 /* R0: 1 means restore context */
str r3, [r2, #0] /* Force Pend SV */
/* These call should not return */
bx lr /* Unnecessary ... will not return */
.size up_fullcontextrestore, .-up_fullcontextrestore
.align 2
.type nvic_intctrl, object
nvic_intctrl:
.word NVIC_INTCTRL
.size nvic_intctrl, .-nvic_intctrl
.end

13
arch/arm/src/lm3s/lm3s_internal.h
View File

@ -43,6 +43,10 @@
#include <nuttx/config.h>
#include <sys/types.h>
#include "up_internal.h"
#include "lm3s_memorymap.h"
#include "lm3s_gpio.h"
/************************************************************************************
* Definitions
************************************************************************************/
@ -247,6 +251,15 @@ EXTERN void up_clockconfig(void);
EXTERN int lm3s_configgpio(uint32 bitset);
/****************************************************************************
* Name: lm3s_pendsv
*
* Description:
* This is PendSV exception handler that performs context switching
*
****************************************************************************/
EXTERN int lm3s_pendsv(int irq, FAR void *context);
#undef EXTERN
#if defined(__cplusplus)

15
arch/arm/src/lm3s/lm3s_irq.c
View File

@ -173,6 +173,12 @@ void up_irqinitialize(void)
current_regs = NULL;
/* Attach the PendSV exception handler. This is used for performing
* context switches.
*/
irq_attach(LMSB_IRQ_PENDSV, lm3s_pendsv);
/* Attach all processor exceptions (except reset and sys tick) */
#ifdef CONFIG_DEBUG
@ -183,7 +189,6 @@ void up_irqinitialize(void)
irq_attach(LMSB_IRQ_USAGEFAULT, lm3s_usagefault);
irq_attach(LMSB_IRQ_SVCALL, lm3s_svcall);
irq_attach(LMSB_IRQ_DBGMONITOR, lm3s_dbgmonitor);
irq_attach(LMSB_IRQ_PENDSV, lm3s_pendsv);
irq_attach(LMSB_IRQ_RESERVED, lm3s_reserved);
#endif
@ -368,14 +373,6 @@ int lm3s_dbgmonitor(int irq, FAR void *context)
return 0;
}
int lm3s_pendsv(int irq, FAR void *context)
{
(void)irqsave();
dbg("PANIC!!! PendSV received\n");
PANIC(OSERR_UNEXPECTEDISR);
return 0;
}
int lm3s_reserved(int irq, FAR void *context)
{
(void)irqsave();

118
arch/arm/src/lm3s/lm3s_pendsv.c Normal file
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@ -0,0 +1,118 @@
/****************************************************************************
* arch/arm/src/lm3s/lm3s_pendsv.c
* arch/arm/src/chip/lm3s_pendsv.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <sys/types.h>
#include <string.h>
#include <assert.h>
#include <debug.h>
#include <arch/irq.h>
#include "os_internal.h"
#include "lm3s_internal.h"
/****************************************************************************
* Private Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lm3xs_pendxv
*
* Description:
* This is PendSV exception handler that performs context switching
*
****************************************************************************/
int lm3s_pendsv(int irq, FAR void *context)
{
uint32 *svregs = (uint32*)context;
uint32 *tcbregs = (uint32*)svregs[REG_R1];
DEBUGASSERT(svregs && svregs == current_regs && tcbregs);
/* The PendSV software interrupt is called with R0 = PendSV command and R1 =
* the TCB register save area.
*/
switch (svregs[REG_R0])
{
/* R0=0: This is a save context command. In this case, we simply need
* to copy the svregs to the tdbregs and return.
*/
case 0:
memcpy(tcbregs, svregs, XCPTCONTEXT_SIZE);
break;
/* R1=1: This a restore context command. In this case, we simply need to
* set current_regs to tcbrgs. svregs == current_regs is the normal exception
* turn. By setting current_regs = tcbregs, we force the return through
* the saved context.
*/
case 1:
current_regs = tcbregs;
break;
default:
PANIC(OSERR_INTERNAL);
break;
}
return OK;
}

3
arch/arm/src/lm3s/lm3s_vectors.S
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@ -1,5 +1,6 @@
/************************************************************************************
* arch/arm/src/lm3s/lm3slm3s_vectors.S
* arch/arm/src/lm3s/lm3s_vectors.S
* arch/arm/src/chip/lm3s_vectors.S
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>