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Diffstat (limited to 'misc/Obsoleted/arch/8051/src/up_restorecontext.c')
| -rw-r--r-- | misc/Obsoleted/arch/8051/src/up_restorecontext.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/misc/Obsoleted/arch/8051/src/up_restorecontext.c b/misc/Obsoleted/arch/8051/src/up_restorecontext.c new file mode 100644 index 000000000..6966866ee --- /dev/null +++ b/misc/Obsoleted/arch/8051/src/up_restorecontext.c @@ -0,0 +1,296 @@ +/************************************************************************** + * up_restorecontext.c + * + * Copyright (C) 2007, 2009 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 <stdint.h> +#include <nuttx/irq.h> +#include "up_internal.h" + +/************************************************************************** + * Private Definitions + **************************************************************************/ + +/************************************************************************** + * Private Types + **************************************************************************/ + +/************************************************************************** + * Private Function Prototypes + **************************************************************************/ + +/************************************************************************** + * Global Variables + **************************************************************************/ + +/************************************************************************** + * Private Variables + **************************************************************************/ + +/************************************************************************** + * Private Functions + **************************************************************************/ + +/************************************************************************** + * Public Functions + **************************************************************************/ + +/************************************************************************** + * Name: up_restoreregisters + * + * Description: + * Restore the saved registers from the context save area. This function + * is called from up_restorecontext (below) and also from interrupt + * handling logic. + * + * Note that this function does not restore: + * a, dptr, ie - these are saved in the stack area + * sp - this can be inferred from g_irqtos or struct xcptontext.nbytes. + * + * Inputs: + * context - the context register array from which to restore the + * register values + * + * Return: + * None + * + **************************************************************************/ + +void up_restoreregisters(FAR uint8_t *regs) _naked +{ + _asm + movx a, @dptr + mov b, a + inc dptr + movx a, @dptr + mov r2, a + inc dptr + movx a, @dptr + mov r3, a + inc dptr + movx a, @dptr + mov r4, a + inc dptr + movx a, @dptr + mov r5, a + inc dptr + movx a, @dptr + mov r6, a + inc dptr + movx a, @dptr + mov r7, a + inc dptr + movx a, @dptr + mov r0, a + inc dptr + movx a, @dptr + mov r1, a + inc dptr + movx a, @dptr + mov psw, a + inc dptr + movx a, @dptr + mov _bp, a + ret + _endasm; +} + +/************************************************************************** + * Name: up_restorecontext + * + * Description: + * Restore the stack specified in the context structure and return to + * that context + * + * Inputs: + * context - Holds the stack content of the context to return to + * + * Return: + * This function does not return. + * + **************************************************************************/ + +void up_restorecontext(FAR struct xcptcontext *context) __naked +{ + _asm + ar2 = 0x02 + ar3 = 0x03 + ar4 = 0x04 + ar5 = 0x05 + ar6 = 0x06 + ar7 = 0x07 + ar0 = 0x00 + ar1 = 0x01 + + /* Dump the contents of the saved frame before it is copied back + * to memory/registers. + */ + +#ifdef CONFIG_SWITCH_FRAME_DUMP + push dpl + push dph + lcall _up_dumpframe + pop dph + pop dpl +#endif + + /* Interrupts should be disabled for the following. up_popcontext() will + * set the new interrupt state correctly. + */ + + clr ea + + /* The following logic will copy the stack from the + * context save structure into IRAM. We cannot use + * the stack in anyway during this copy. Instead, + * we will use registers as follows: + * + * R0 - Holds the working 8-bit IRAM pointer + * R1 - Not used + * R2-3 - Holds the working 16-bit XRAM pointer + * R4 - Holds the working byte count + * R5 - Holds the new stack pointer + * R6-7 - Saved context pointer + */ + + /* Fetch r4 = context->nbytes */ + + movx a, @dptr + mov r4, a + + /* Save the new stack pointer in r5 */ + + add a, #(STACK_BASE-1) + mov r5, a + + /* Save r2-3 and r6-r7 = &context->stack */ + + inc dptr + mov r2, dpl + mov r3, dph + mov r6, dpl + mov r7, dph + + /* Set r0 = stack base address */ + + mov r0, #STACK_BASE + + /* Top of the copy loop -- we cannot use the stack + * again until we finish the copy and set the new + * stack pointer (saved in r5) + */ +00001$: + mov a, r4 /* a = bytes left to transfer */ + dec r4 /* (for next time through the loop) */ + jz 00002$ /* Jump if a = 0 (done) */ + + /* Fetch the next byte from context->stack */ + + mov dpl, r2 + mov dph, r3 + movx a, @dptr + + /* Increment the XRAM pointer */ + + inc dptr + mov r2, dpl + mov r3, dph + + /* Save the next byte into IRAM */ + + mov @r0, a + + /* Increment the IRAM pointer */ + + inc r0 + sjmp 00001$ +00002$: + + /* Set the new stack pointer and recover the + * context->stack pointer. + */ + + mov sp, r5 + mov dpl, r6 + mov dph, r7 + + /* Dump the stack contents after they have + * been restored to IRAM + */ + +#ifdef CONFIG_SWITCH_FRAME_DUMP + push dpl + push dph + lcall _up_dumpstack + pop dph + pop dpl +#endif + /* Get the pointer to the register save area */ + + mov a, #STACK_SIZE + add a, dpl + mov dpl, a + clr a + addc a, dph + mov dph, a + + /* Restore registers from the register save area */ + + lcall _up_restoreregisters + + /* Restore registers from the new stack */ + + pop dph + pop dpl + + /* Restore the interrupt state per the stored IE value */ + + pop acc + jb acc.7,00003$ + clr ie.7 + sjmp 00004$ + 00003$: + setb ie.7 + + 00004$: + pop acc + ret + _endasm; +} + + |