uboot 移植之gd_t，bd_t

gd_t定义在uboot/include/asm-arm/global_data.h

/*
 * (C) Copyright 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
 */

#ifndef	__ASM_GBL_DATA_H
#define __ASM_GBL_DATA_H
/*
 * The following data structure is placed in some memory wich is
 * available very early after boot (like DPRAM on MPC8xx/MPC82xx, or
 * some locked parts of the data cache) to allow for a minimum set of
 * global variables during system initialization (until we have set
 * up the memory controller so that we can use RAM).
 *
 * Keep it *SMALL* and remember to set CONFIG_SYS_GBL_DATA_SIZE > sizeof(gd_t)
 */

typedef	struct	global_data {
	bd_t		*bd;
	unsigned long	flags;
	unsigned long	baudrate;
	unsigned long	have_console;	/* serial_init() was called */
	unsigned long	env_addr;	/* Address  of Environment struct */
	unsigned long	env_valid;	/* Checksum of Environment valid? */
	unsigned long	fb_base;	/* base address of frame buffer */
#ifdef CONFIG_VFD
	unsigned char	vfd_type;	/* display type */
#endif
#if 0
	unsigned long	cpu_clk;	/* CPU clock in Hz!		*/
	unsigned long	bus_clk;
	phys_size_t	ram_size;	/* RAM size */
	unsigned long	reset_status;	/* reset status register at boot */
#endif
	void		**jt;		/* jump table */
} gd_t;

/*
 * Global Data Flags
 */
#define	GD_FLG_RELOC	0x00001		/* Code was relocated to RAM		*/
#define	GD_FLG_DEVINIT	0x00002		/* Devices have been initialized	*/
#define	GD_FLG_SILENT	0x00004		/* Silent mode				*/
#define	GD_FLG_POSTFAIL	0x00008		/* Critical POST test failed		*/
#define	GD_FLG_POSTSTOP	0x00010		/* POST seqeunce aborted		*/
#define	GD_FLG_LOGINIT	0x00020		/* Log Buffer has been initialized	*/
#define GD_FLG_DISABLE_CONSOLE	0x00040		/* Disable console (in & out)	 */

#define DECLARE_GLOBAL_DATA_PTR     register volatile gd_t *gd asm ("r8")//

#endif /* __ASM_GBL_DATA_H */

bd_t定义在uboot/include/asm-arm/u-boot.h

/*
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Marius Groeger <mgroeger@sysgo.de>
 *
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Alex Zuepke <azu@sysgo.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
 *
 ********************************************************************
 * NOTE: This header file defines an interface to U-Boot. Including
 * this (unmodified) header file in another file is considered normal
 * use of U-Boot, and does *not* fall under the heading of "derived
 * work".
 ********************************************************************
 */

#ifndef _U_BOOT_H_
#define _U_BOOT_H_	1

typedef struct bd_info {
    int			bi_baudrate;	/* serial console baudrate */
    unsigned long	bi_ip_addr;	/* IP Address */
    struct environment_s	       *bi_env;
    ulong	        bi_arch_number;	/* unique id for this board */
    ulong	        bi_boot_params;	/* where this board expects params */
    struct				/* RAM configuration */
    {
	ulong start;
	ulong size;
    }			bi_dram[CONFIG_NR_DRAM_BANKS];
} bd_t;

#define bi_env_data bi_env->data
#define bi_env_crc  bi_env->crc

#endif	/* _U_BOOT_H_ */

可参考
http://hi.baidu.com/shaoyi1110/blog/item/5246f5d1e0ac93123bf3cf56.html