Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / arch / arm / kernel / compat.c
1 /*
2  *  linux/arch/arm/kernel/compat.c
3  *
4  *  Copyright (C) 2001 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * We keep the old params compatibility cruft in one place (here)
11  * so we don't end up with lots of mess around other places.
12  *
13  * NOTE:
14  *  The old struct param_struct is deprecated, but it will be kept in
15  *  the kernel for 5 years from now (2001). This will allow boot loaders
16  *  to convert to the new struct tag way.
17  */
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/init.h>
22
23 #include <asm/setup.h>
24 #include <asm/mach-types.h>
25 #include <asm/page.h>
26
27 #include <asm/mach/arch.h>
28
29 #include "compat.h"
30
31 /*
32  * Usage:
33  *  - do not go blindly adding fields, add them at the end
34  *  - when adding fields, don't rely on the address until
35  *    a patch from me has been released
36  *  - unused fields should be zero (for future expansion)
37  *  - this structure is relatively short-lived - only
38  *    guaranteed to contain useful data in setup_arch()
39  *
40  * This is the old deprecated way to pass parameters to the kernel
41  */
42 struct param_struct {
43     union {
44         struct {
45             unsigned long page_size;            /*  0 */
46             unsigned long nr_pages;             /*  4 */
47             unsigned long ramdisk_size;         /*  8 */
48             unsigned long flags;                /* 12 */
49 #define FLAG_READONLY   1
50 #define FLAG_RDLOAD     4
51 #define FLAG_RDPROMPT   8
52             unsigned long rootdev;              /* 16 */
53             unsigned long video_num_cols;       /* 20 */
54             unsigned long video_num_rows;       /* 24 */
55             unsigned long video_x;              /* 28 */
56             unsigned long video_y;              /* 32 */
57             unsigned long memc_control_reg;     /* 36 */
58             unsigned char sounddefault;         /* 40 */
59             unsigned char adfsdrives;           /* 41 */
60             unsigned char bytes_per_char_h;     /* 42 */
61             unsigned char bytes_per_char_v;     /* 43 */
62             unsigned long pages_in_bank[4];     /* 44 */
63             unsigned long pages_in_vram;        /* 60 */
64             unsigned long initrd_start;         /* 64 */
65             unsigned long initrd_size;          /* 68 */
66             unsigned long rd_start;             /* 72 */
67             unsigned long system_rev;           /* 76 */
68             unsigned long system_serial_low;    /* 80 */
69             unsigned long system_serial_high;   /* 84 */
70             unsigned long mem_fclk_21285;       /* 88 */
71         } s;
72         char unused[256];
73     } u1;
74     union {
75         char paths[8][128];
76         struct {
77             unsigned long magic;
78             char n[1024 - sizeof(unsigned long)];
79         } s;
80     } u2;
81     char commandline[COMMAND_LINE_SIZE];
82 };
83
84 static struct tag * __init memtag(struct tag *tag, unsigned long start, unsigned long size)
85 {
86         tag = tag_next(tag);
87         tag->hdr.tag = ATAG_MEM;
88         tag->hdr.size = tag_size(tag_mem32);
89         tag->u.mem.size = size;
90         tag->u.mem.start = start;
91
92         return tag;
93 }
94
95 static void __init build_tag_list(struct param_struct *params, void *taglist)
96 {
97         struct tag *tag = taglist;
98
99         if (params->u1.s.page_size != PAGE_SIZE) {
100                 printk(KERN_WARNING "Warning: bad configuration page, "
101                        "trying to continue\n");
102                 return;
103         }
104
105         printk(KERN_DEBUG "Converting old-style param struct to taglist\n");
106
107 #ifdef CONFIG_ARCH_NETWINDER
108         if (params->u1.s.nr_pages != 0x02000 &&
109             params->u1.s.nr_pages != 0x04000 &&
110             params->u1.s.nr_pages != 0x08000 &&
111             params->u1.s.nr_pages != 0x10000) {
112                 printk(KERN_WARNING "Warning: bad NeTTrom parameters "
113                        "detected, using defaults\n");
114
115                 params->u1.s.nr_pages = 0x1000; /* 16MB */
116                 params->u1.s.ramdisk_size = 0;
117                 params->u1.s.flags = FLAG_READONLY;
118                 params->u1.s.initrd_start = 0;
119                 params->u1.s.initrd_size = 0;
120                 params->u1.s.rd_start = 0;
121         }
122 #endif
123
124         tag->hdr.tag  = ATAG_CORE;
125         tag->hdr.size = tag_size(tag_core);
126         tag->u.core.flags = params->u1.s.flags & FLAG_READONLY;
127         tag->u.core.pagesize = params->u1.s.page_size;
128         tag->u.core.rootdev = params->u1.s.rootdev;
129
130         tag = tag_next(tag);
131         tag->hdr.tag = ATAG_RAMDISK;
132         tag->hdr.size = tag_size(tag_ramdisk);
133         tag->u.ramdisk.flags = (params->u1.s.flags & FLAG_RDLOAD ? 1 : 0) |
134                                (params->u1.s.flags & FLAG_RDPROMPT ? 2 : 0);
135         tag->u.ramdisk.size  = params->u1.s.ramdisk_size;
136         tag->u.ramdisk.start = params->u1.s.rd_start;
137
138         tag = tag_next(tag);
139         tag->hdr.tag = ATAG_INITRD;
140         tag->hdr.size = tag_size(tag_initrd);
141         tag->u.initrd.start = params->u1.s.initrd_start;
142         tag->u.initrd.size  = params->u1.s.initrd_size;
143
144         tag = tag_next(tag);
145         tag->hdr.tag = ATAG_SERIAL;
146         tag->hdr.size = tag_size(tag_serialnr);
147         tag->u.serialnr.low = params->u1.s.system_serial_low;
148         tag->u.serialnr.high = params->u1.s.system_serial_high;
149
150         tag = tag_next(tag);
151         tag->hdr.tag = ATAG_REVISION;
152         tag->hdr.size = tag_size(tag_revision);
153         tag->u.revision.rev = params->u1.s.system_rev;
154
155 #ifdef CONFIG_ARCH_ACORN
156         if (machine_is_riscpc()) {
157                 int i;
158                 for (i = 0; i < 4; i++)
159                         tag = memtag(tag, PHYS_OFFSET + (i << 26),
160                                  params->u1.s.pages_in_bank[i] * PAGE_SIZE);
161         } else
162 #endif
163         tag = memtag(tag, PHYS_OFFSET, params->u1.s.nr_pages * PAGE_SIZE);
164
165 #ifdef CONFIG_FOOTBRIDGE
166         if (params->u1.s.mem_fclk_21285) {
167                 tag = tag_next(tag);
168                 tag->hdr.tag = ATAG_MEMCLK;
169                 tag->hdr.size = tag_size(tag_memclk);
170                 tag->u.memclk.fmemclk = params->u1.s.mem_fclk_21285;
171         }
172 #endif
173
174 #ifdef CONFIG_ARCH_EBSA285
175         if (machine_is_ebsa285()) {
176                 tag = tag_next(tag);
177                 tag->hdr.tag = ATAG_VIDEOTEXT;
178                 tag->hdr.size = tag_size(tag_videotext);
179                 tag->u.videotext.x            = params->u1.s.video_x;
180                 tag->u.videotext.y            = params->u1.s.video_y;
181                 tag->u.videotext.video_page   = 0;
182                 tag->u.videotext.video_mode   = 0;
183                 tag->u.videotext.video_cols   = params->u1.s.video_num_cols;
184                 tag->u.videotext.video_ega_bx = 0;
185                 tag->u.videotext.video_lines  = params->u1.s.video_num_rows;
186                 tag->u.videotext.video_isvga  = 1;
187                 tag->u.videotext.video_points = 8;
188         }
189 #endif
190
191 #ifdef CONFIG_ARCH_ACORN
192         tag = tag_next(tag);
193         tag->hdr.tag = ATAG_ACORN;
194         tag->hdr.size = tag_size(tag_acorn);
195         tag->u.acorn.memc_control_reg = params->u1.s.memc_control_reg;
196         tag->u.acorn.vram_pages       = params->u1.s.pages_in_vram;
197         tag->u.acorn.sounddefault     = params->u1.s.sounddefault;
198         tag->u.acorn.adfsdrives       = params->u1.s.adfsdrives;
199 #endif
200
201         tag = tag_next(tag);
202         tag->hdr.tag = ATAG_CMDLINE;
203         tag->hdr.size = (strlen(params->commandline) + 3 +
204                          sizeof(struct tag_header)) >> 2;
205         strcpy(tag->u.cmdline.cmdline, params->commandline);
206
207         tag = tag_next(tag);
208         tag->hdr.tag = ATAG_NONE;
209         tag->hdr.size = 0;
210
211         memmove(params, taglist, ((int)tag) - ((int)taglist) +
212                                  sizeof(struct tag_header));
213 }
214
215 void __init convert_to_tag_list(struct tag *tags)
216 {
217         struct param_struct *params = (struct param_struct *)tags;
218         build_tag_list(params, &params->u2);
219 }
220
221 void __init squash_mem_tags(struct tag *tag)
222 {
223         for (; tag->hdr.size; tag = tag_next(tag))
224                 if (tag->hdr.tag == ATAG_MEM)
225                         tag->hdr.tag = ATAG_NONE;
226 }