/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSScoreMemory
*
* @brief This source file contains the i386/pc386 implementation of
* _Memory_Get().
*/
/*
* Copyright (C) 2019 embedded brains GmbH & Co. KG
*
* Copyright (C) 1989, 2017 On-Line Applications Research Corporation (OAR)
*
* 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.
*
* 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.
*/
/* #define BSP_GET_WORK_AREA_DEBUG */
#include <bsp.h>
#include <bsp/bootcard.h>
#include <rtems/sysinit.h>
#ifdef BSP_GET_WORK_AREA_DEBUG
#include <rtems/bspIo.h>
#endif
/*
* These are provided by the linkcmds.
*/
extern char WorkAreaBase[];
extern char HeapSize[];
extern char RamSize[];
/* rudimentary multiboot info */
struct multiboot_info {
uint32_t flags; /* start.S only raises flags for items actually */
/* saved; this allows us to check for the size */
/* of the data structure. */
uint32_t mem_lower; /* avail kB in lower memory */
uint32_t mem_upper; /* avail kB in lower memory */
/* ... (unimplemented) */
};
extern struct multiboot_info _boot_multiboot_info;
/*
* This is the first address of the memory we can use for the RTEMS
* Work Area.
*/
static uintptr_t rtemsWorkAreaStart;
/*
* Board's memory size easily be overridden by application.
*/
uint32_t bsp_mem_size = 0;
static void bsp_size_memory(void)
{
uintptr_t topAddr;
/* Set the value of start of free memory. */
rtemsWorkAreaStart = (uint32_t)WorkAreaBase;
/* Align the RTEMS Work Area at beginning of free memory. */
if (rtemsWorkAreaStart & (CPU_ALIGNMENT - 1)) /* not aligned => align it */
rtemsWorkAreaStart = (rtemsWorkAreaStart+CPU_ALIGNMENT) & ~(CPU_ALIGNMENT-1);
/* The memory detection algorithm is very crude; try
* to use multiboot info, if possible (set from start.S)
*/
if ( ((uintptr_t)RamSize == (uintptr_t) 0xFFFFFFFF) &&
(_boot_multiboot_info.flags & 1) &&
_boot_multiboot_info.mem_upper ) {
topAddr = _boot_multiboot_info.mem_upper * 1024;
#ifdef BSP_GET_WORK_AREA_DEBUG
printk( "Multiboot info says we have 0x%08x\n", topAddr );
#endif
} else if ( (uintptr_t) RamSize == (uintptr_t) 0xFFFFFFFF ) {
uintptr_t lowest;
uint32_t val;
int i;
/*
* We have to dynamically size memory. Memory size can be anything
* between no less than 2M and 2048M. If we can write a value to
* an address and read the same value back, then the memory is there.
*
* WARNING: This can detect memory which should be reserved for
* graphics controllers which share the CPU's RAM.
*/
/* find the lowest 1M boundary to probe */
lowest = ((rtemsWorkAreaStart + (1<<20)) >> 20) + 1;
if ( lowest < 2 )
lowest = 2;
for (i=2048; i>=lowest; i--) {
topAddr = i*1024*1024 - 4;
*(volatile uint32_t*)topAddr = topAddr;
}
for(i=lowest; i<=2048; i++) {
topAddr = i*1024*1024 - 4;
val = *(volatile uint32_t*)topAddr;
if (val != topAddr) {
break;
}
}
topAddr = (i-1)*1024*1024;
#ifdef BSP_GET_WORK_AREA_DEBUG
printk( "Dynamically sized to 0x%08x\n", topAddr );
#endif
} else {
topAddr = (uintptr_t) RamSize;
#ifdef BSP_GET_WORK_AREA_DEBUG
printk( "hardcoded to 0x%08x\n", topAddr );
#endif
}
bsp_mem_size = topAddr;
}
static Memory_Area _Memory_Areas[ 1 ];
static void bsp_memory_initialize( void )
{
/*
* We need to determine how much memory there is in the system.
*/
bsp_size_memory();
_Memory_Initialize_by_size(
&_Memory_Areas[0],
(void *) rtemsWorkAreaStart,
(uintptr_t) bsp_mem_size - (uintptr_t) rtemsWorkAreaStart
);
}
RTEMS_SYSINIT_ITEM(
bsp_memory_initialize,
RTEMS_SYSINIT_MEMORY,
RTEMS_SYSINIT_ORDER_MIDDLE
);
static const Memory_Information _Memory_Information =
MEMORY_INFORMATION_INITIALIZER( _Memory_Areas );
const Memory_Information *_Memory_Get( void )
{
return &_Memory_Information;
}
