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, start: PHYS_OFFSET, size: 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, taglist: &params->u2);
214}
215

source code of linux/arch/arm/kernel/atags_compat.c