atags_compat.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/arch/arm/kernel/atags_compat.c
  4 *
  5 *  Copyright (C) 2001 Russell King
  6 *
  7 * We keep the old params compatibility cruft in one place (here)
  8 * so we don't end up with lots of mess around other places.
  9 *
 10 * NOTE:
 11 *  The old struct param_struct is deprecated, but it will be kept in
 12 *  the kernel for 5 years from now (2001). This will allow boot loaders
 13 *  to convert to the new struct tag way.
 14 */
 15#include <linux/types.h>
 16#include <linux/kernel.h>
 17#include <linux/string.h>
 18#include <linux/init.h>
 19
 20#include <asm/setup.h>
 21#include <asm/mach-types.h>
 22#include <asm/page.h>
 23
 24#include <asm/mach/arch.h>
 25
 26#include "atags.h"
 27
 28/*
 29 * Usage:
 30 *  - do not go blindly adding fields, add them at the end
 31 *  - when adding fields, don't rely on the address until
 32 *    a patch from me has been released
 33 *  - unused fields should be zero (for future expansion)
 34 *  - this structure is relatively short-lived - only
 35 *    guaranteed to contain useful data in setup_arch()
 36 *
 37 * This is the old deprecated way to pass parameters to the kernel
 38 */
 39struct param_struct {
 40    union {
 41	struct {
 42	    unsigned long page_size;		/*  0 */
 43	    unsigned long nr_pages;		/*  4 */
 44	    unsigned long ramdisk_size;		/*  8 */
 45	    unsigned long flags;		/* 12 */
 46#define FLAG_READONLY	1
 47#define FLAG_RDLOAD	4
 48#define FLAG_RDPROMPT	8
 49	    unsigned long rootdev;		/* 16 */
 50	    unsigned long video_num_cols;	/* 20 */
 51	    unsigned long video_num_rows;	/* 24 */
 52	    unsigned long video_x;		/* 28 */
 53	    unsigned long video_y;		/* 32 */
 54	    unsigned long memc_control_reg;	/* 36 */
 55	    unsigned char sounddefault;		/* 40 */
 56	    unsigned char adfsdrives;		/* 41 */
 57	    unsigned char bytes_per_char_h;	/* 42 */
 58	    unsigned char bytes_per_char_v;	/* 43 */
 59	    unsigned long pages_in_bank[4];	/* 44 */
 60	    unsigned long pages_in_vram;	/* 60 */
 61	    unsigned long initrd_start;		/* 64 */
 62	    unsigned long initrd_size;		/* 68 */
 63	    unsigned long rd_start;		/* 72 */
 64	    unsigned long system_rev;		/* 76 */
 65	    unsigned long system_serial_low;	/* 80 */
 66	    unsigned long system_serial_high;	/* 84 */
 67	    unsigned long mem_fclk_21285;       /* 88 */
 68	} s;
 69	char unused[256];
 70    } u1;
 71    union {
 72	char paths[8][128];
 73	struct {
 74	    unsigned long magic;
 75	    char n[1024 - sizeof(unsigned long)];
 76	} s;
 77    } u2;
 78    char commandline[COMMAND_LINE_SIZE];
 79};
 80
 81static struct tag * __init memtag(struct tag *tag, unsigned long start, unsigned long size)
 82{
 83	tag = tag_next(tag);
 84	tag->hdr.tag = ATAG_MEM;
 85	tag->hdr.size = tag_size(tag_mem32);
 86	tag->u.mem.size = size;
 87	tag->u.mem.start = start;
 88
 89	return tag;
 90}
 91
 92static void __init build_tag_list(struct param_struct *params, void *taglist)
 93{
 94	struct tag *tag = taglist;
 95
 96	if (params->u1.s.page_size != PAGE_SIZE) {
 97		pr_warn("Warning: bad configuration page, trying to continue\n");
 98		return;
 99	}
100
101	printk(KERN_DEBUG "Converting old-style param struct to taglist\n");
102
103#ifdef CONFIG_ARCH_NETWINDER
104	if (params->u1.s.nr_pages != 0x02000 &&
105	    params->u1.s.nr_pages != 0x04000 &&
106	    params->u1.s.nr_pages != 0x08000 &&
107	    params->u1.s.nr_pages != 0x10000) {
108		pr_warn("Warning: bad NeTTrom parameters detected, using defaults\n");
109
110		params->u1.s.nr_pages = 0x1000;	/* 16MB */
111		params->u1.s.ramdisk_size = 0;
112		params->u1.s.flags = FLAG_READONLY;
113		params->u1.s.initrd_start = 0;
114		params->u1.s.initrd_size = 0;
115		params->u1.s.rd_start = 0;
116	}
117#endif
118
119	tag->hdr.tag  = ATAG_CORE;
120	tag->hdr.size = tag_size(tag_core);
121	tag->u.core.flags = params->u1.s.flags & FLAG_READONLY;
122	tag->u.core.pagesize = params->u1.s.page_size;
123	tag->u.core.rootdev = params->u1.s.rootdev;
124
125	tag = tag_next(tag);
126	tag->hdr.tag = ATAG_RAMDISK;
127	tag->hdr.size = tag_size(tag_ramdisk);
128	tag->u.ramdisk.flags = (params->u1.s.flags & FLAG_RDLOAD ? 1 : 0) |
129			       (params->u1.s.flags & FLAG_RDPROMPT ? 2 : 0);
130	tag->u.ramdisk.size  = params->u1.s.ramdisk_size;
131	tag->u.ramdisk.start = params->u1.s.rd_start;
132
133	tag = tag_next(tag);
134	tag->hdr.tag = ATAG_INITRD;
135	tag->hdr.size = tag_size(tag_initrd);
136	tag->u.initrd.start = params->u1.s.initrd_start;
137	tag->u.initrd.size  = params->u1.s.initrd_size;
138
139	tag = tag_next(tag);
140	tag->hdr.tag = ATAG_SERIAL;
141	tag->hdr.size = tag_size(tag_serialnr);
142	tag->u.serialnr.low = params->u1.s.system_serial_low;
143	tag->u.serialnr.high = params->u1.s.system_serial_high;
144
145	tag = tag_next(tag);
146	tag->hdr.tag = ATAG_REVISION;
147	tag->hdr.size = tag_size(tag_revision);
148	tag->u.revision.rev = params->u1.s.system_rev;
149
150#ifdef CONFIG_ARCH_ACORN
151	if (machine_is_riscpc()) {
152		int i;
153		for (i = 0; i < 4; i++)
154			tag = memtag(tag, PHYS_OFFSET + (i << 26),
155				 params->u1.s.pages_in_bank[i] * PAGE_SIZE);
156	} else
157#endif
158	tag = memtag(tag, PHYS_OFFSET, params->u1.s.nr_pages * PAGE_SIZE);
159
160#ifdef CONFIG_FOOTBRIDGE
161	if (params->u1.s.mem_fclk_21285) {
162		tag = tag_next(tag);
163		tag->hdr.tag = ATAG_MEMCLK;
164		tag->hdr.size = tag_size(tag_memclk);
165		tag->u.memclk.fmemclk = params->u1.s.mem_fclk_21285;
166	}
167#endif
168
169#ifdef CONFIG_ARCH_EBSA285
170	if (machine_is_ebsa285()) {
171		tag = tag_next(tag);
172		tag->hdr.tag = ATAG_VIDEOTEXT;
173		tag->hdr.size = tag_size(tag_videotext);
174		tag->u.videotext.x            = params->u1.s.video_x;
175		tag->u.videotext.y            = params->u1.s.video_y;
176		tag->u.videotext.video_page   = 0;
177		tag->u.videotext.video_mode   = 0;
178		tag->u.videotext.video_cols   = params->u1.s.video_num_cols;
179		tag->u.videotext.video_ega_bx = 0;
180		tag->u.videotext.video_lines  = params->u1.s.video_num_rows;
181		tag->u.videotext.video_isvga  = 1;
182		tag->u.videotext.video_points = 8;
183	}
184#endif
185
186#ifdef CONFIG_ARCH_ACORN
187	tag = tag_next(tag);
188	tag->hdr.tag = ATAG_ACORN;
189	tag->hdr.size = tag_size(tag_acorn);
190	tag->u.acorn.memc_control_reg = params->u1.s.memc_control_reg;
191	tag->u.acorn.vram_pages       = params->u1.s.pages_in_vram;
192	tag->u.acorn.sounddefault     = params->u1.s.sounddefault;
193	tag->u.acorn.adfsdrives       = params->u1.s.adfsdrives;
194#endif
195
196	tag = tag_next(tag);
197	tag->hdr.tag = ATAG_CMDLINE;
198	tag->hdr.size = (strlen(params->commandline) + 3 +
199			 sizeof(struct tag_header)) >> 2;
200	strcpy(tag->u.cmdline.cmdline, params->commandline);
201
202	tag = tag_next(tag);
203	tag->hdr.tag = ATAG_NONE;
204	tag->hdr.size = 0;
205
206	memmove(params, taglist, ((int)tag) - ((int)taglist) +
207				 sizeof(struct tag_header));
208}
209
210void __init convert_to_tag_list(struct tag *tags)
211{
212	struct param_struct *params = (struct param_struct *)tags;
213	build_tag_list(params, &params->u2);
214}