u-boot/arch/x86/cpu/qemu/dram.c
Bin Meng a65b25d148 x86: Support QEMU x86 targets
This commit introduces the initial U-Boot support for QEMU x86 targets.
U-Boot can boot from coreboot as a payload, or directly without coreboot.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Merged in patch 'x86: qemu: Add CMD_NET to qemu-x86_defconfig
   https://patchwork.ozlabs.org/patch/479745/
2015-06-04 02:39:38 -06:00

46 lines
1 KiB
C

/*
* Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/post.h>
#include <asm/arch/qemu.h>
DECLARE_GLOBAL_DATA_PTR;
int dram_init(void)
{
u32 ram;
outb(HIGH_RAM_ADDR, CMOS_ADDR_PORT);
ram = ((u32)inb(CMOS_DATA_PORT)) << 14;
outb(LOW_RAM_ADDR, CMOS_ADDR_PORT);
ram |= ((u32)inb(CMOS_DATA_PORT)) << 6;
ram += 16 * 1024;
gd->ram_size = ram * 1024;
post_code(POST_DRAM);
return 0;
}
void dram_init_banksize(void)
{
gd->bd->bi_dram[0].start = 0;
gd->bd->bi_dram[0].size = gd->ram_size;
}
/*
* This function looks for the highest region of memory lower than 4GB which
* has enough space for U-Boot where U-Boot is aligned on a page boundary.
* It overrides the default implementation found elsewhere which simply
* picks the end of ram, wherever that may be. The location of the stack,
* the relocation address, and how far U-Boot is moved by relocation are
* set in the global data structure.
*/
ulong board_get_usable_ram_top(ulong total_size)
{
return gd->ram_size;
}