u-boot/arch/x86/include/asm/cmos_layout.h
Bin Meng ba65808e7d x86: fsp: Save stack address to CMOS for next S3 boot
At the end of pre-relocation phase, save the new stack address
to CMOS and use it as the stack on next S3 boot for fsp_init()
continuation function.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
2017-05-17 17:11:46 +08:00

31 lines
1 KiB
C

/*
* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef __CMOS_LAYOUT_H
#define __CMOS_LAYOUT_H
/*
* The RTC internal registers and RAM is organized as two banks of 128 bytes
* each, called the standard and extended banks. The first 14 bytes of the
* standard bank contain the RTC time and date information along with four
* registers, A - D, that are used for configuration of the RTC. The extended
* bank contains a full 128 bytes of battery backed SRAM.
*
* For simplicity in U-Boot we only support CMOS in the standard bank, and
* its base address starts from offset 0x10, which leaves us 112 bytes space.
*/
#define CMOS_BASE 0x10
/*
* The file records all offsets off CMOS_BASE that is currently used by
* U-Boot for various reasons. It is put in such a unified place in order
* to be consistent across platforms.
*/
/* stack address for S3 boot in a FSP configuration, 4 bytes */
#define CMOS_FSP_STACK_ADDR CMOS_BASE
#endif /* __CMOS_LAYOUT_H */