xref: /openbmc/u-boot/arch/x86/cpu/qemu/dram.c (revision 1d2c0506)
1 /*
2  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <asm/post.h>
9 #include <asm/arch/qemu.h>
10 
11 DECLARE_GLOBAL_DATA_PTR;
12 
13 int dram_init(void)
14 {
15 	u32 ram;
16 
17 	outb(HIGH_RAM_ADDR, CMOS_ADDR_PORT);
18 	ram = ((u32)inb(CMOS_DATA_PORT)) << 14;
19 	outb(LOW_RAM_ADDR, CMOS_ADDR_PORT);
20 	ram |= ((u32)inb(CMOS_DATA_PORT)) << 6;
21 	ram += 16 * 1024;
22 
23 	gd->ram_size = ram * 1024;
24 	post_code(POST_DRAM);
25 
26 	return 0;
27 }
28 
29 void dram_init_banksize(void)
30 {
31 	gd->bd->bi_dram[0].start = 0;
32 	gd->bd->bi_dram[0].size = gd->ram_size;
33 }
34 
35 /*
36  * This function looks for the highest region of memory lower than 4GB which
37  * has enough space for U-Boot where U-Boot is aligned on a page boundary.
38  * It overrides the default implementation found elsewhere which simply
39  * picks the end of ram, wherever that may be. The location of the stack,
40  * the relocation address, and how far U-Boot is moved by relocation are
41  * set in the global data structure.
42  */
43 ulong board_get_usable_ram_top(ulong total_size)
44 {
45 	return gd->ram_size;
46 }
47