ossc/software/sys_controller_bsp/HAL/src/alt_remap_uncached.c
2016-02-23 01:03:50 +02:00

55 lines
3.4 KiB
C

/******************************************************************************
* *
* License Agreement *
* *
* Copyright (c) 2003,2007 Altera Corporation, San Jose, California, USA. *
* All rights reserved. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
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* Software is furnished to do so, subject to the following conditions: *
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* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
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******************************************************************************/
#include "sys/alt_warning.h"
#include "sys/alt_cache.h"
#include "system.h"
/*
* Convert a pointer to a block of cached memory into a block of uncached memory.
* Return a pointer that should be used to access the uncached memory.
*
* This routine was created for Nios II Gen1 cores which allow mixing cacheable and
* uncachable data in the same data cache line. So, they could take any memory region
* and make it uncached. However, Nios II Gen2 cores don't support mixing cacheable
* and uncachable data in the same data cache line so require the memory region to
* be aligned to a cache line boundary and must be an integer number of cache line
* bytes in size. So, software on a Nios II Gen2 core shouldn't really be using this
* function so it fails with a link error.
*/
volatile void*
alt_remap_uncached(void* ptr, alt_u32 len)
{
/* Generate a link time error, should this function ever be called. */
ALT_LINK_ERROR("alt_remap_uncached() is not available because Nios II Gen2 cores with data caches don't support mixing cacheable and uncacheable data on the same line.");
return NULL;
}