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  */
39 struct 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 
memtag(struct tag * tag,unsigned long start,unsigned long size)81 static 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 
build_tag_list(struct param_struct * params,void * taglist)92 static 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 
convert_to_tag_list(struct tag * tags)210 void __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 }
215