u-boot-brain/board/samsung/smdk5250/spl_boot.c

/*
 * Copyright (C) 2012 Samsung Electronics
 *
 * 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<config.h>

enum boot_mode {
	BOOT_MODE_MMC = 4,
	BOOT_MODE_SERIAL = 20,
	/* Boot based on Operating Mode pin settings */
	BOOT_MODE_OM = 32,
	BOOT_MODE_USB,	/* Boot using USB download */
};

	typedef u32 (*spi_copy_func_t)(u32 offset, u32 nblock, u32 dst);
	typedef u32 (*usb_copy_func_t)(void);

/*
 * Set/clear program flow prediction and return the previous state.
 */
static int config_branch_prediction(int set_cr_z)
{
	unsigned int cr;

	/* System Control Register: 11th bit Z Branch prediction enable */
	cr = get_cr();
	set_cr(set_cr_z ? cr | CR_Z : cr & ~CR_Z);

	return cr & CR_Z;
}

/*
* Copy U-boot from mmc to RAM:
* COPY_BL2_FNPTR_ADDR: Address in iRAM, which Contains
* Pointer to API (Data transfer from mmc to ram)
*/
void copy_uboot_to_ram(void)
{
	spi_copy_func_t spi_copy;
	usb_copy_func_t usb_copy;

	int is_cr_z_set;
	unsigned int sec_boot_check;
	enum boot_mode bootmode = BOOT_MODE_OM;
	u32 (*copy_bl2)(u32, u32, u32);

	/* Read iRAM location to check for secondary USB boot mode */
	sec_boot_check = readl(EXYNOS_IRAM_SECONDARY_BASE);
	if (sec_boot_check == EXYNOS_USB_SECONDARY_BOOT)
		bootmode = BOOT_MODE_USB;

	if (bootmode == BOOT_MODE_OM)
		bootmode = readl(EXYNOS5_POWER_BASE) & OM_STAT;

	switch (bootmode) {
	case BOOT_MODE_SERIAL:
		spi_copy = *(spi_copy_func_t *)EXYNOS_COPY_SPI_FNPTR_ADDR;
		spi_copy(SPI_FLASH_UBOOT_POS, CONFIG_BL2_SIZE,
						CONFIG_SYS_TEXT_BASE);
		break;
	case BOOT_MODE_MMC:
		copy_bl2 = (void *) *(u32 *)COPY_BL2_FNPTR_ADDR;
		copy_bl2(BL2_START_OFFSET, BL2_SIZE_BLOC_COUNT,
						CONFIG_SYS_TEXT_BASE);
		break;
	case BOOT_MODE_USB:
		/*
		 * iROM needs program flow prediction to be disabled
		 * before copy from USB device to RAM
		 */
		is_cr_z_set = config_branch_prediction(0);
		usb_copy = *(usb_copy_func_t *)
				EXYNOS_COPY_USB_FNPTR_ADDR;
		usb_copy();
		config_branch_prediction(is_cr_z_set);
		break;
	default:
		break;
	}
}

void board_init_f(unsigned long bootflag)
{
	__attribute__((noreturn)) void (*uboot)(void);
	copy_uboot_to_ram();

	/* Jump to U-Boot image */
	uboot = (void *)CONFIG_SYS_TEXT_BASE;
	(*uboot)();
	/* Never returns Here */
}

/* Place Holders */
void board_init_r(gd_t *id, ulong dest_addr)
{
	/* Function attribute is no-return */
	/* This Function never executes */
	while (1)
		;
}

void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3) {}