u-boot/arch/riscv/include/asm/setup.h

/*
 *  linux/arch/nds32/include/asm/setup.h
 *
 * Copyright (C) 1997-1999 Russell King
 * Copyright (C) 2008 Andes Technology Corporation
 * Copyright (C) 2013 Ken Kuo (ken_kuo@andestech.com)
 * Copyright (C) 2017 Rick Chen (rick@andestech.com)
 *
 * SPDX-License-Identifier:	GPL-2.0
 *
 *  Structure passed to kernel to tell it about the
 *  hardware it's running on.  See Documentation/arm/Setup
 *  for more info.
 */
#ifndef __RISCV_SETUP_H
#define __RISCV_SETUP_H

#define COMMAND_LINE_SIZE 256

/* The list ends with an ATAG_NONE node. */
#define ATAG_NONE	0x00000000

struct tag_header {
	u32 size;
	u32 tag;
};

/* The list must start with an ATAG_CORE node */
#define ATAG_CORE	0x54410001

struct tag_core {
	u32 flags;		/* bit 0 = read-only */
	u32 pagesize;
	u32 rootdev;
};

/* it is allowed to have multiple ATAG_MEM nodes */
#define ATAG_MEM	0x54410002

struct tag_mem32 {
	u32	size;
	u32	start;	/* physical start address */
};

/* VGA text type displays */
#define ATAG_VIDEOTEXT	0x54410003

struct tag_videotext {
	u8		x;
	u8		y;
	u16		video_page;
	u8		video_mode;
	u8		video_cols;
	u16		video_ega_bx;
	u8		video_lines;
	u8		video_isvga;
	u16		video_points;
};

/* describes how the ramdisk will be used in kernel */
#define ATAG_RAMDISK	0x54410004

struct tag_ramdisk {
	u32 flags;	/* bit 0 = load, bit 1 = prompt */
	u32 size;	/* decompressed ramdisk size in _kilo_ bytes */
	u32 start;	/* starting block of floppy-based RAM disk image */
};

/*
 * this one accidentally used virtual addresses - as such,
 * it's deprecated.
 * describes where the compressed ramdisk image lives (virtual address)
 */
#define ATAG_INITRD		0x54410005

/* describes where the compressed ramdisk image lives (physical address) */
#define ATAG_INITRD2	0x54420005

struct tag_initrd {
	u32 start;	/* physical start address */
	u32 size;	/* size of compressed ramdisk image in bytes */
};

/* board serial number. "64 bits should be enough for everybody" */
#define ATAG_SERIAL		0x54410006

struct tag_serialnr {
	u32 low;
	u32 high;
};

/* board revision */
#define ATAG_REVISION	0x54410007

struct tag_revision {
	u32 rev;
};

/* initial values for vesafb-type framebuffers. see struct screen_info
 * in include/linux/tty.h
 */
#define ATAG_VIDEOLFB	0x54410008

struct tag_videolfb {
	u16		lfb_width;
	u16		lfb_height;
	u16		lfb_depth;
	u16		lfb_linelength;
	u32		lfb_base;
	u32		lfb_size;
	u8		red_size;
	u8		red_pos;
	u8		green_size;
	u8		green_pos;
	u8		blue_size;
	u8		blue_pos;
	u8		rsvd_size;
	u8		rsvd_pos;
};

/* command line: \0 terminated string */
#define ATAG_CMDLINE	0x54410009

struct tag_cmdline {
	char	cmdline[COMMAND_LINE_SIZE];
};

struct tag {
	struct tag_header hdr;
	union {
		struct tag_core		core;
		struct tag_mem32	mem;
		struct tag_videotext	videotext;
		struct tag_ramdisk	ramdisk;
		struct tag_initrd	initrd;
		struct tag_serialnr	serialnr;
		struct tag_revision	revision;
		struct tag_videolfb	videolfb;
		struct tag_cmdline	cmdline;
	} u;
};

struct tagtable {
	u32 tag;
	int (*parse)(const struct tag *);
};

#define tag_member_present(_tag, member)				\
	typeof(_tag) (tag) = (_tag); \
	((unsigned long)(&((struct tag *)0L)->member + 1)	\
		<= (tag)->hdr.size * 4)

#define tag_next(_t)	\
	typeof(_t) (t) = (_t); \
	((struct tag *)((u32 *)(t) + (t)->hdr.size))
#define tag_size(type)	((sizeof(struct tag_header) + sizeof(struct type)) >> 2)

#define for_each_tag(_t, base) \
	typeof(_t) (t) = (_t); \
	for (t = base; t->hdr.size; t = tag_next(t))

#ifdef __KERNEL__

#define __tag __used __attribute__((__section__(".taglist")))
#define __tagtable(tag, fn) \
static struct tagtable __tagtable_##fn __tag = { tag, fn }

/*
 * Memory map description
 */
#define NR_BANKS 8

struct meminfo {
	int nr_banks;
	struct {
		unsigned long start;
		unsigned long size;
		int           node;
	} bank[NR_BANKS];
};

/*
 * Early command line parameters.
 */
struct early_params {
	const char *arg;
	void (*fn)(char **p);
};

#define __early_param(name, fn)					\
static struct early_params __early_##fn __used	\
__attribute__((__section__("__early_param"))) = { name, fn }

#endif
#endif