cpu.c

uboot详细解读可用启动引导LINUX2.6内核

/*
 * U-boot - cpu.c CPU specific functions
 *
 * Copyright (c) 2005-2008 Analog Devices Inc.
 *
 * (C) Copyright 2000-2004
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * Licensed under the GPL-2 or later.
 */

#include <common.h>
#include <command.h>
#include <asm/blackfin.h>
#include <asm/cplb.h>
#include <asm/mach-common/bits/core.h>
#include <asm/mach-common/bits/mpu.h>
#include <asm/mach-common/bits/trace.h>

#include "cpu.h"
#include "serial.h"

void icache_enable(void)
{
	bfin_write_IMEM_CONTROL(bfin_read_IMEM_CONTROL() | (IMC | ENICPLB));
	SSYNC();
}

void icache_disable(void)
{
	bfin_write_IMEM_CONTROL(bfin_read_IMEM_CONTROL() & ~(IMC | ENICPLB));
	SSYNC();
}

int icache_status(void)
{
	return bfin_read_IMEM_CONTROL() & ENICPLB;
}

void dcache_enable(void)
{
	bfin_write_DMEM_CONTROL(bfin_read_DMEM_CONTROL() | (ACACHE_BCACHE | ENDCPLB | PORT_PREF0));
	SSYNC();
}

void dcache_disable(void)
{
	bfin_write_DMEM_CONTROL(bfin_read_DMEM_CONTROL() & ~(ACACHE_BCACHE | ENDCPLB | PORT_PREF0));
	SSYNC();
}

int dcache_status(void)
{
	return bfin_read_DMEM_CONTROL() & ENDCPLB;
}

__attribute__ ((__noreturn__))
void cpu_init_f(ulong bootflag, ulong loaded_from_ldr)
{
	/* Build a NOP slide over the LDR jump block.  Whee! */
	serial_early_puts("NOP Slide\n");
	char nops[0xC];
	memset(nops, 0x00, sizeof(nops));
	extern char _stext_l1;
	memcpy(&_stext_l1 - sizeof(nops), nops, sizeof(nops));

	if (!loaded_from_ldr) {
		/* Relocate sections into L1 if the LDR didn't do it -- don't
		 * check length because the linker script does the size
		 * checking at build time.
		 */
		serial_early_puts("L1 Relocate\n");
		extern char _stext_l1, _etext_l1, _stext_l1_lma;
		memcpy(&_stext_l1, &_stext_l1_lma, (&_etext_l1 - &_stext_l1));
		extern char _sdata_l1, _edata_l1, _sdata_l1_lma;
		memcpy(&_sdata_l1, &_sdata_l1_lma, (&_edata_l1 - &_sdata_l1));
	}
#if defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__)
	/* The BF537 bootrom will reset the EBIU_AMGCTL register on us
	 * after it has finished loading the LDR.  So configure it again.
	 */
	else
		bfin_write_EBIU_AMGCTL(CONFIG_EBIU_AMGCTL_VAL);
#endif

#ifdef CONFIG_DEBUG_DUMP
	/* Turn on hardware trace buffer */
	bfin_write_TBUFCTL(TBUFPWR | TBUFEN);
#endif

#ifndef CONFIG_PANIC_HANG
	/* Reset upon a double exception rather than just hanging.
	 * Do not do bfin_read on SWRST as that will reset status bits.
	 */
	bfin_write_SWRST(DOUBLE_FAULT);
#endif

	serial_early_puts("Board init flash\n");
	board_init_f(bootflag);
}

int exception_init(void)
{
	bfin_write_EVT3(trap);
	return 0;
}

int irq_init(void)
{
#ifdef SIC_IMASK0
	bfin_write_SIC_IMASK0(0);
	bfin_write_SIC_IMASK1(0);
# ifdef SIC_IMASK2
	bfin_write_SIC_IMASK2(0);
# endif
#elif defined(SICA_IMASK0)
	bfin_write_SICA_IMASK0(0);
	bfin_write_SICA_IMASK1(0);
#else
	bfin_write_SIC_IMASK(0);
#endif
	bfin_write_EVT2(evt_default);	/* NMI */
	bfin_write_EVT5(evt_default);	/* hardware error */
	bfin_write_EVT6(evt_default);	/* core timer */
	bfin_write_EVT7(evt_default);
	bfin_write_EVT8(evt_default);
	bfin_write_EVT9(evt_default);
	bfin_write_EVT10(evt_default);
	bfin_write_EVT11(evt_default);
	bfin_write_EVT12(evt_default);
	bfin_write_EVT13(evt_default);
	bfin_write_EVT14(evt_default);
	bfin_write_EVT15(evt_default);
	bfin_write_ILAT(0);
	CSYNC();
	/* enable all interrupts except for core timer */
	irq_flags = 0xffffffbf;
	local_irq_enable();
	CSYNC();
	return 0;
}