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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2013-03-21 17:35:08 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2013-03-21 17:35:08 +0000 |
commit | aee2b5f63b4eef1751605731688fd80d20593b81 (patch) | |
tree | 936c832a3c90c8ba410bcd050d0c97c4cfdb7cb0 /nuttx/arch/z80/src/common/up_stackframe.c | |
parent | 55a46f0500f36567ce352048454534135aff92f2 (diff) | |
download | px4-nuttx-aee2b5f63b4eef1751605731688fd80d20593b81.tar.gz px4-nuttx-aee2b5f63b4eef1751605731688fd80d20593b81.tar.bz2 px4-nuttx-aee2b5f63b4eef1751605731688fd80d20593b81.zip |
Add a up_stack_frame() interface to allocate a frame of data on a task's stack.
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5768 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/arch/z80/src/common/up_stackframe.c')
-rw-r--r-- | nuttx/arch/z80/src/common/up_stackframe.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/nuttx/arch/z80/src/common/up_stackframe.c b/nuttx/arch/z80/src/common/up_stackframe.c new file mode 100644 index 000000000..01a7b0881 --- /dev/null +++ b/nuttx/arch/z80/src/common/up_stackframe.c @@ -0,0 +1,132 @@ +/**************************************************************************** + * arch/z80/src/common/up_stackframe.c + * + * Copyright (C) 2013 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 <sys/types.h> +#include <stdint.h> +#include <sched.h> +#include <debug.h> + +#include <nuttx/arch.h> + +#include "up_internal.h" + +/**************************************************************************** + * Pre-processor Macros + ****************************************************************************/ +/* The Z80 stack does not need to be aligned. Here is is aligned at word + * (4 byte) boundary. + */ + +#define STACK_ALIGNMENT 4 + +/* Stack alignment macros */ + +#define STACK_ALIGN_MASK (STACK_ALIGNMENT-1) +#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK) +#define STACK_ALIGN_UP(a) (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK) + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Global Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_stack_frame + * + * Description: + * Allocate a stack frame in the TCB's stack to hold thread-specific data. + * This function may be called anytime after up_create_stack() or + * up_use_stack() have been called but before the task has been started. + * + * Thread data may be kept in the stack (instead of in the TCB) if it is + * accessed by the user code directory. This includes such things as + * argv[]. The stack memory is guaranteed to be in the same protection + * domain as the thread. + * + * The following TCB fields will be re-initialized: + * + * - adj_stack_size: Stack size after removal of the stack frame from + * the stack + * - adj_stack_ptr: Adjusted initial stack pointer after the frame has + * been removed from the stack. This will still be the initial value + * of the stack pointer when the task is started. + * + * Inputs: + * - tcb: The TCB of new task + * - frame_size: The size of the stack frame to allocate. + * + * Returned Value: + * - A pointer to bottom of the allocated stack frame. NULL will be + * returned on any failures. The alignment of the returned value is + * the same as the alignment of the stack itself. + * + ****************************************************************************/ + +FAR void *up_stack_frame(FAR struct tcb_s *tcb, size_t frame_size) +{ + uintptr_t topaddr; + + /* Align the frame_size */ + + frame_size = STACK_ALIGN_UP(frame_size); + + /* Is there already a stack allocated? Is it big enough? */ + + if (!tcb->stack_alloc_ptr || tcb->adj_stack_size <= frame_size) + { + return NULL; + } + + /* Save the adjusted stack values in the struct tcb_s */ + + topaddr = (uintptr_t)tcb->adj_stack_ptr - frame_size; + tcb->adj_stack_ptr = (FAR void *)topaddr; + tcb->adj_stack_size -= frame_size; + + return (FAR void *)(topaddr + sizeof(uint32_t)); +} |