cpu.c

linux下的BOOT程序原码,有需要的可以来下,保证好用

/*
 * (C) Copyright 2000-2003
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * 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
 */

/*
 * CPU specific code for the MPC8220 CPUs
 */

#include <common.h>
#include <watchdog.h>
#include <command.h>
#include <mpc8220.h>
#include <asm/processor.h>

int checkcpu (void)
{
	DECLARE_GLOBAL_DATA_PTR;

	ulong clock = gd->cpu_clk;
	char buf[32];

	puts ("CPU:   ");

	printf (CPU_ID_STR);

	printf (" (JTAG ID %08lx)", *(vu_long *) (CFG_MBAR + 0x50));

	printf (" at %s MHz\n", strmhz (buf, clock));

	return 0;
}

/* ------------------------------------------------------------------------- */

int do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
	volatile gptmr8220_t *gptmr = (volatile gptmr8220_t *) MMAP_GPTMR;
	ulong msr;

	/* Interrupts and MMU off */
	__asm__ __volatile__ ("mfmsr    %0":"=r" (msr):);

	msr &= ~(MSR_ME | MSR_EE | MSR_IR | MSR_DR);
	__asm__ __volatile__ ("mtmsr    %0"::"r" (msr));

	/* Charge the watchdog timer */
	gptmr->Prescl = 10;
	gptmr->Count = 1;

	gptmr->Mode = GPT_TMS_SGPIO;

	gptmr->Control = GPT_CTRL_WDEN | GPT_CTRL_CE;

	return 1;
}

/* ------------------------------------------------------------------------- */

/*
 * Get timebase clock frequency (like cpu_clk in Hz)
 *
 */
unsigned long get_tbclk (void)
{
	DECLARE_GLOBAL_DATA_PTR;

	ulong tbclk;

	tbclk = (gd->bus_clk + 3L) / 4L;

	return (tbclk);
}

/* ------------------------------------------------------------------------- */