lib_nios/board.c

/*
 * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
 * Scott McNutt <smcnutt@psyent.com>
 *
 * (C) Copyright 2000-2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * 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
 */

#include <common.h>
#include <devices.h>
#include <watchdog.h>


/*
 * All attempts to come up with a "common" initialization sequence
 * that works for all boards and architectures failed: some of the
 * requirements are just _too_ different. To get rid of the resulting
 * mess of board dependend #ifdef'ed code we now make the whole
 * initialization sequence configurable to the user.
 *
 * The requirements for any new initalization function is simple: it
 * receives a pointer to the "global data" structure as it's only
 * argument, and returns an integer return code, where 0 means
 * "continue" and != 0 means "fatal error, hang the system".
 */


extern void malloc_bin_reloc (void);
typedef int (init_fnc_t) (void);
extern unsigned _vectors[];

/*
 * Begin and End of memory area for malloc(), and current "brk"
 */
static	ulong	mem_malloc_start = 0;
static	ulong	mem_malloc_end	 = 0;
static	ulong	mem_malloc_brk	 = 0;

/*
 * The Malloc area is immediately below the monitor copy in RAM
 */
static void mem_malloc_init (void)
{
	mem_malloc_start = CFG_MALLOC_BASE;
	mem_malloc_end = mem_malloc_start + CFG_MALLOC_LEN;
	mem_malloc_brk = mem_malloc_start;
	memset ((void *) mem_malloc_start,
		0,
		mem_malloc_end - mem_malloc_start);
}

void *sbrk (ptrdiff_t increment)
{
	ulong old = mem_malloc_brk;
	ulong new = old + increment;

	if ((new < mem_malloc_start) || (new > mem_malloc_end)) {
		return (NULL);
	}
	mem_malloc_brk = new;
	return ((void *) old);
}


/************************************************************************
 * Initialization sequence						*
 ***********************************************************************/

init_fnc_t *init_sequence[] = {

#if defined(CONFIG_BOARD_PRE_INIT)
	board_pre_init,		/* Call board-specific init code early.*/
#endif

	env_init,
	serial_init,
	console_init_f,
	display_options,
	checkcpu,
	checkboard,
	NULL,			/* Terminate this list */
};


/***********************************************************************/
void board_init (void)
{
	DECLARE_GLOBAL_DATA_PTR;

	bd_t *bd;
	init_fnc_t **init_fnc_ptr;

	/* Pointer is writable since we allocated a register for it.
	 * Nios treats CFG_GBL_DATA_OFFSET as an address.
	 */
	gd = (gd_t *)CFG_GBL_DATA_OFFSET;
	memset( gd, 0, CFG_GBL_DATA_SIZE );

	/* Copy exception vectors to the correct location.
	 */
	memcpy( (void *)CFG_VECT_BASE, _vectors, 256 );

	gd->bd = (bd_t *)(gd+1);	/* At end of global data */
	gd->baudrate = CONFIG_BAUDRATE;
	gd->cpu_clk = CONFIG_SYS_CLK_FREQ;

	bd = gd->bd;
	bd->bi_memstart	= CFG_SDRAM_BASE;
	bd->bi_memsize = CFG_SDRAM_SIZE;
	bd->bi_flashstart = CFG_FLASH_BASE;
	bd->bi_sramstart= CFG_SRAM_BASE;
	bd->bi_sramsize	= CFG_SRAM_SIZE;
	bd->bi_baudrate	= CONFIG_BAUDRATE;

	for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
		if ((*init_fnc_ptr) () != 0) {
			hang ();
		}
	}

	bd->bi_flashsize = flash_init();

	mem_malloc_init();
	malloc_bin_reloc();
	env_relocate();

	devices_init();
	jumptable_init();
	console_init_r();
	/*
	 */

	interrupt_init ();
	/* main_loop */
	for (;;) {
		WATCHDOG_RESET ();
		main_loop ();
	}
}


/***********************************************************************/

void hang (void)
{
	puts("### ERROR ### Please reset board ###\n");
	for (;;);
}