ppc405_init_raminfo.c

来自「qnx powerpc MPC8245的 BSP源文件」· C语言 代码 · 共 48 行

/*
 * $QNXLicenseC: 
 * Copyright 2007, QNX Software Systems.  
 *  
 * Licensed under the Apache License, Version 2.0 (the "License"). You  
 * may not reproduce, modify or distribute this software except in  
 * compliance with the License. You may obtain a copy of the License  
 * at: http://www.apache.org/licenses/LICENSE-2.0  
 *  
 * Unless required by applicable law or agreed to in writing, software  
 * distributed under the License is distributed on an "AS IS" basis,  
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied. 
 * 
 * This file may contain contributions from others, either as  
 * contributors under the License or as licensors under other terms.   
 * Please review this entire file for other proprietary rights or license  
 * notices, as well as the QNX Development Suite License Guide at  
 * http://licensing.qnx.com/license-guide/ for other information. 
 * $ 
 */

/*
 * ppc405_init_raminfo.c
 * Tell syspage about our RAM configuration
 */
#include "startup.h"

void ppc405_init_raminfo() 
{
	int i;
	unsigned long dcr;
	unsigned long total = 0;

	// detect 405 memory
	for (i = 0; i < 16; i += 4) {
		set_dcr(PPC405_DCR_SDRAM0_CFGADDR, (i + PPC405_SDRAM0_B0CR));
		dcr = get_dcr(PPC405_DCR_SDRAM0_CFGDATA);

		// bits 19, 18, and 17 represent the size of the bank, where
		// 000 = 4M, 001 = 8M, etc., up to 110 = 256M. 
		if(dcr & 1)	// bank is enabled
			total += (1 << (22 + ((dcr & 0x000e0000) >> 17)));
	}

	add_ram(0, total);
}