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Diffstat (limited to 'nuttx/arch/pjrc-8051/src/up_savecontext.c')
| -rw-r--r-- | nuttx/arch/pjrc-8051/src/up_savecontext.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/nuttx/arch/pjrc-8051/src/up_savecontext.c b/nuttx/arch/pjrc-8051/src/up_savecontext.c new file mode 100644 index 000000000..1405fce4d --- /dev/null +++ b/nuttx/arch/pjrc-8051/src/up_savecontext.c @@ -0,0 +1,167 @@ +/************************************************************************** + * up_savecontext.c + * + * Copyright (C) 2007 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 Gregory Nutt 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 <sys/types.h> +#include <nuttx/irq.h> +#include "up_internal.h" + +/************************************************************************** + * Private Definitions + **************************************************************************/ + +/************************************************************************** + * Private Types + **************************************************************************/ + +/************************************************************************** + * Private Function Prototypes + **************************************************************************/ + +/************************************************************************** + * Global Variables + **************************************************************************/ + +/************************************************************************** + * Private Variables + **************************************************************************/ + +/************************************************************************** + * Private Functions + **************************************************************************/ + +/************************************************************************** + * Name: up_pushcontext + * + * Description: + * Push the current execution context onto the before the stack. Similar + * operations are executed from the interrupt state save. + * + * Inputs: + * None + * + * Return: + * Returns the stack pointer (always non-zero). However, when + * up_popcontext() executes, it will appear as a return from this + * function with return value == 0 + * + **************************************************************************/ + +static ubyte up_pushcontext(void) __naked +{ + /* Push the current execution context onto the stack. */ + + _asm + push acc + push ie + mov dptr, #0 /* Save return value (dpl) = 0 */ + push dpl + push dph + push b + push ar2 + push ar3 + push ar4 + push ar5 + push ar6 + push ar7 + push ar0 + push ar1 + push psw + clr psw + push _bp + + /* And return the current stack pointer value in dpl */ + + mov dpl, sp + ret + _endasm; +} + +/************************************************************************** + * Public Functions + **************************************************************************/ + +/************************************************************************** + * Name: up_savecontext + * + * Description: + * Push the current execution context onto the stack, then save the + * entire stack contents in the provided context structure. + * + * Inputs: + * context - the context structure in which to save the stack info + * + * Return + * 0 = Normal state save return + * 1 = This is the matching return from up_restorecontext() + * + **************************************************************************/ + +ubyte up_savecontext(FAR struct xcptcontext *context) +{ + irqstate_t flags = irqsave(); + ubyte sp = up_pushcontext(); + if (sp) + { + /* Now copy the current stack frame (including the saved execution + * context) from internal RAM to XRAM. + */ + + ubyte nbytes = sp - (STACK_BASE-1); + FAR ubyte *src = (FAR ubyte*)STACK_BASE; + FAR ubyte *dest = context->stack; + + /* Then copy the stack info into the context structure */ + + context->nbytes = nbytes; + while (nbytes--) + { + *dest++ = *src++; + } + + /* Return zero so that the return behavior is similar to setjmp */ + + irqrestore(flags); + return 0; + } + + /* Return one so that the return behavior is similar to setjmp */ + + irqrestore(flags); + return 1; +} |