u-boot-brain/arch/sandbox/include/asm/io.h
Simon Glass 4213fc2913 sandbox: Add un/map_sysmen() to deal with sandbox's ram_buf
Sandbox doesn't actually provide U-Boot access to the machine's physical
memory. Instead it provides a RAM buffer of configurable size, and all
memory accesses are within that buffer. Sandbox memory starts at 0 and
is CONFIG_DRAM_SIZE bytes in size. Allowing access outside this buffer
might produce unpredictable results in the event of an error, and would
expose the host machine's memory architecture to the sandbox U-Boot.

Most U-Boot functions assume that they can just access memory at given
address. For sandbox this is not true.

Add a map_sysmem() call which converts a U-Boot address to a system
address. In most cases this is a NOP, but for sandbox it returns a
pointer to that memory inside the RAM buffer.

To get a U-Boot feature to work correctly within sandbox, you should call
map_sysmem() to get a pointer to the address, and then use that address for
any U-Boot memory accesses.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-02-28 19:09:22 -08:00

52 lines
1.5 KiB
C

/*
* Copyright (c) 2011 The Chromium OS Authors.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* Given a physical address and a length, return a virtual address
* that can be used to access the memory range with the caching
* properties specified by "flags".
*/
#define MAP_NOCACHE (0)
#define MAP_WRCOMBINE (0)
#define MAP_WRBACK (0)
#define MAP_WRTHROUGH (0)
void *map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags);
/*
* Take down a mapping set up by map_physmem().
*/
static inline void unmap_physmem(void *vaddr, unsigned long flags)
{
}
/* For sandbox, we want addresses to point into our RAM buffer */
static inline void *map_sysmem(phys_addr_t paddr, unsigned long len)
{
return map_physmem(paddr, len, MAP_WRBACK);
}
static inline void unmap_sysmem(const void *vaddr)
{
}