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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2011-04-08 01:33:21 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2011-04-08 01:33:21 +0000 |
commit | 45474d6e667a62ce96979008613e3b2fd5c713e0 (patch) | |
tree | 01f2eb0877f875664d664924e456d7187f71ee93 /nuttx/arch/arm/src/cortexm3/exc_return.h | |
parent | 8ca829501528bb3895be055cece3af6a99dac0eb (diff) | |
download | px4-nuttx-45474d6e667a62ce96979008613e3b2fd5c713e0.tar.gz px4-nuttx-45474d6e667a62ce96979008613e3b2fd5c713e0.tar.bz2 px4-nuttx-45474d6e667a62ce96979008613e3b2fd5c713e0.zip |
Modify interrupt handling for privileged/unprivileged mode
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3480 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/arch/arm/src/cortexm3/exc_return.h')
-rw-r--r-- | nuttx/arch/arm/src/cortexm3/exc_return.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/cortexm3/exc_return.h b/nuttx/arch/arm/src/cortexm3/exc_return.h new file mode 100644 index 000000000..06c0e723f --- /dev/null +++ b/nuttx/arch/arm/src/cortexm3/exc_return.h @@ -0,0 +1,90 @@ +/************************************************************************************ + * arch/arm/src/cortexm3/exc_return.h + * + * Copyright (C) 2011 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. + * + ************************************************************************************/ + +#ifndef __ARCH_ARM_SRC_COMMON_CORTEXM_EXC_RETURN_H +#define __ARCH_ARM_SRC_COMMON_CORTEXM_EXC_RETURN_H + +/************************************************************************************ + * Included Files + ************************************************************************************/ + +#include <nuttx/config.h> + +/************************************************************************************ + * Pre-processor Definitions + ************************************************************************************/ + +/* The processor saves an EXC_RETURN value to the LR on exception entry. The + * exception mechanism relies on this value to detect when the processor has + * completed an exception handler. Bits[31:4] of an EXC_RETURN value are + * 0xfffffffX. When the processor loads a value matching this pattern to the + * PC it detects that the operation is a not a normal branch operation and, + * instead, that the exception is complete. Therefore, it starts the exception + * return sequence. Bits[3:0] of the EXC_RETURN value indicate the required + * return stack and processor mode: + */ + +/* EXC_RETURN_HANDLER: Return to handler mode. Exception return gets state from + * the main stack. Execution uses MSP after return. + */ + +#define EXC_RETURN_HANDLER 0xfffffff1 + +/* EXC_RETURN_PRIVTHR: Return to privileged thread mode. Exception return gets + * state from the main stack. Execution uses MSP after return. + */ + +#define EXC_RETURN_PRIVTHR 0xfffffff9 + +/* EXC_RETURN_UNPRIVTHR: Return to unprivileged thread mode. Exception return gets + * state from the process stack. Execution uses PSP after return. + */ + +#define EXC_RETURN_UNPRIVTHR 0xfffffffd + +/* In the kernel build is not selected, then all threads run in privileged thread + * mode. + */ + +#ifdef CONFIG_NUTTX_KERNEL +# define EXC_RETURN 0xfffffff9 +#endif + +/************************Th************************************************************ + * Inline Functions + ************************************************************************************/ + +#endif /* __ARCH_ARM_SRC_COMMON_CORTEXM_EXC_RETURN_H */ + |