LXR linux/arch/arm/kernel/atags

   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}
 215