xref: /OK3568_Linux_fs/u-boot/arch/x86/cpu/qemu/dram.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <asm/post.h>
9*4882a593Smuzhiyun #include <asm/arch/qemu.h>
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
12*4882a593Smuzhiyun 
dram_init(void)13*4882a593Smuzhiyun int dram_init(void)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun 	u32 ram;
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun 	outb(HIGH_RAM_ADDR, CMOS_ADDR_PORT);
18*4882a593Smuzhiyun 	ram = ((u32)inb(CMOS_DATA_PORT)) << 14;
19*4882a593Smuzhiyun 	outb(LOW_RAM_ADDR, CMOS_ADDR_PORT);
20*4882a593Smuzhiyun 	ram |= ((u32)inb(CMOS_DATA_PORT)) << 6;
21*4882a593Smuzhiyun 	ram += 16 * 1024;
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun 	gd->ram_size = ram * 1024;
24*4882a593Smuzhiyun 	post_code(POST_DRAM);
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 	return 0;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun 
dram_init_banksize(void)29*4882a593Smuzhiyun int dram_init_banksize(void)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun 	gd->bd->bi_dram[0].start = 0;
32*4882a593Smuzhiyun 	gd->bd->bi_dram[0].size = gd->ram_size;
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	return 0;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun /*
38*4882a593Smuzhiyun  * This function looks for the highest region of memory lower than 4GB which
39*4882a593Smuzhiyun  * has enough space for U-Boot where U-Boot is aligned on a page boundary.
40*4882a593Smuzhiyun  * It overrides the default implementation found elsewhere which simply
41*4882a593Smuzhiyun  * picks the end of ram, wherever that may be. The location of the stack,
42*4882a593Smuzhiyun  * the relocation address, and how far U-Boot is moved by relocation are
43*4882a593Smuzhiyun  * set in the global data structure.
44*4882a593Smuzhiyun  */
board_get_usable_ram_top(ulong total_size)45*4882a593Smuzhiyun ulong board_get_usable_ram_top(ulong total_size)
46*4882a593Smuzhiyun {
47*4882a593Smuzhiyun 	return gd->ram_size;
48*4882a593Smuzhiyun }
49