diff options
Diffstat (limited to 'nuttx/arch/arm/src/lm3s/lm3s_svcall.c')
-rw-r--r-- | nuttx/arch/arm/src/lm3s/lm3s_svcall.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_svcall.c b/nuttx/arch/arm/src/lm3s/lm3s_svcall.c new file mode 100644 index 000000000..d6c7bf517 --- /dev/null +++ b/nuttx/arch/arm/src/lm3s/lm3s_svcall.c @@ -0,0 +1,146 @@ +/**************************************************************************** + * arch/arm/src/lm3s/lm3s_svcall.c + * arch/arm/src/chip/lm3s_svcall.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" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#undef DEBUG_SVCALL /* Define to debug SVCall */ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: lm3s_svcall + * + * Description: + * This is SVCall exception handler that performs context switching + * + ****************************************************************************/ + +int lm3s_svcall(int irq, FAR void *context) +{ + uint32 *svregs = (uint32*)context; + uint32 *tcbregs = (uint32*)svregs[REG_R1]; + + DEBUGASSERT(svregs && svregs == current_regs && tcbregs); + + /* The SVCall software interrupt is called with R0 = SVC command and R1 = + * the TCB register save area. + */ + + sllvdbg("Command: %d svregs: %p tcbregs: %08x\n", svregs[REG_R0], svregs, tcbregs); + +#ifdef DEBUG_SVCALL + lldbg("SVCall Entry:\n"); + lldbg(" R0: %08x %08x %08x %08x %08x %08x %08x %08x\n", + svregs[REG_R0], svregs[REG_R1], svregs[REG_R2], svregs[REG_R3], + svregs[REG_R4], svregs[REG_R5], svregs[REG_R6], svregs[REG_R7]); + lldbg(" R8: %08x %08x %08x %08x %08x %08x %08x %08x\n", + svregs[REG_R8], svregs[REG_R9], svregs[REG_R10], svregs[REG_R11], + svregs[REG_R12], svregs[REG_R13], svregs[REG_R14], svregs[REG_R15]); + lldbg(" PSR=%08x\n", svregs[REG_XPSR]); +#endif + + /* Handle the SVCall according to the command in R0 */ + + 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; + } + +#ifdef DEBUG_SVCALL + lldbg("SVCall Return:\n"); + lldbg(" R0: %08x %08x %08x %08x %08x %08x %08x %08x\n", + current_regs[REG_R0], current_regs[REG_R1], current_regs[REG_R2], current_regs[REG_R3], + current_regs[REG_R4], current_regs[REG_R5], current_regs[REG_R6], current_regs[REG_R7]); + lldbg(" R8: %08x %08x %08x %08x %08x %08x %08x %08x\n", + current_regs[REG_R8], current_regs[REG_R9], current_regs[REG_R10], current_regs[REG_R11], + current_regs[REG_R12], current_regs[REG_R13], current_regs[REG_R14], current_regs[REG_R15]); + lldbg(" PSR=%08x\n", current_regs[REG_XPSR]); +#endif + + return OK; +} |