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Diffstat (limited to 'nuttx/arch/hc/src/common/up_usestack.c')
-rwxr-xr-x | nuttx/arch/hc/src/common/up_usestack.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/nuttx/arch/hc/src/common/up_usestack.c b/nuttx/arch/hc/src/common/up_usestack.c new file mode 100755 index 000000000..c5eb6d8e5 --- /dev/null +++ b/nuttx/arch/hc/src/common/up_usestack.c @@ -0,0 +1,117 @@ +/**************************************************************************** + * arch/hc/src/common/up_usestack.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 <sched.h> +#include <debug.h> +#include <nuttx/kmalloc.h> +#include <nuttx/arch.h> +#include "up_internal.h" + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Global Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_use_stack + * + * Description: + * Setup up stack-related information in the TCB using pre-allocated + * stack memory + * + * The following TCB fields must be initialized: + * adj_stack_size: Stack size after adjustment for hardware, processor, etc. + * This value is retained only for debug purposes. + * stack_alloc_ptr: Pointer to allocated stack + * adj_stack_ptr: Adjusted stack_alloc_ptr for HW. The initial value of the + * stack pointer. + * + * Inputs: + * tcb: The TCB of new task + * stack_size: The allocated stack size. + * + ****************************************************************************/ + +STATUS up_use_stack(_TCB *tcb, void *stack, size_t stack_size) +{ + size_t top_of_stack; + size_t size_of_stack; + + if (tcb->stack_alloc_ptr && tcb->adj_stack_size != stack_size) + { + sched_free(tcb->stack_alloc_ptr); + tcb->stack_alloc_ptr = NULL; + } + + /* Save the stack allocation */ + + tcb->stack_alloc_ptr = stack; + + /* The CPU12 uses a push-down stack: the stack grows + * toward lower addresses in memory. Because the CPU12 stack + * operates as a decrement then store stack, the value assigned + * to the initial stack pointer is one more than the last valid + * stack address. + */ + + top_of_stack = (size_t)tcb->stack_alloc_ptr + stack_size; + + /* The CPU12 stack should be aligned at half-word (2 byte) + * boundaries. If necessary top_of_stack must be rounded + * down to the next boundary + */ + + top_of_stack &= ~1; + size_of_stack = top_of_stack - (size_t)tcb->stack_alloc_ptr; + + /* Save the adjusted stack values in the _TCB */ + + tcb->adj_stack_ptr = (uint32*)top_of_stack; + tcb->adj_stack_size = size_of_stack; + return OK; +}
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