src/southbridge/amd/cimx/sb800/ramtop.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2010 Advanced Micro Devices, Inc.
 *
 * 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; version 2 of the License.
 *
 * 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.
 */

#include <stdint.h>
#include <arch/io.h>
#include <arch/acpi.h>
#include <cbmem.h>
#include "SBPLATFORM.h"

int acpi_get_sleep_type(void)
{
	u16 tmp = inw(PM1_CNT_BLK_ADDRESS);
	tmp = ((tmp & (7 << 10)) >> 10);
	return (int)tmp;
}

#if IS_ENABLED(CONFIG_LATE_CBMEM_INIT)

#ifndef __PRE_RAM__
void backup_top_of_ram(uint64_t ramtop)
{
	u32 dword = (u32) ramtop;
	int nvram_pos = 0xf8, i; /* temp */
	for (i = 0; i<4; i++) {
		outb(nvram_pos, BIOSRAM_INDEX);
		outb((dword >>(8 * i)) & 0xff , BIOSRAM_DATA);
		nvram_pos++;
	}
}
#endif

unsigned long get_top_of_ram(void)
{
	u32 xdata = 0;
	int xnvram_pos = 0xf8, xi;
	if (acpi_get_sleep_type() != 3)
		return 0;
	for (xi = 0; xi<4; xi++) {
		outb(xnvram_pos, BIOSRAM_INDEX);
		xdata &= ~(0xff << (xi * 8));
		xdata |= inb(BIOSRAM_DATA) << (xi *8);
		xnvram_pos++;
	}
	return (unsigned long) xdata;
}

#endif