// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/arch/arm/kernel/atags_compat.c
 *
 *  Copyright (C) 2001 Russell King
 *
 * We keep the old params compatibility cruft in one place (here)
 * so we don't end up with lots of mess around other places.
 *
 * NOTE:
 *  The old struct param_struct is deprecated, but it will be kept in
 *  the kernel for 5 years from now (2001). This will allow boot loaders
 *  to convert to the new struct tag way.
 */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>

#include <asm/setup.h>
#include <asm/mach-types.h>
#include <asm/page.h>

#include <asm/mach/arch.h>

#include "atags.h"

/*
 * Usage:
 *  - do not go blindly adding fields, add them at the end
 *  - when adding fields, don't rely on the address until
 *    a patch from me has been released
 *  - unused fields should be zero (for future expansion)
 *  - this structure is relatively short-lived - only
 *    guaranteed to contain useful data in setup_arch()
 *
 * This is the old deprecated way to pass parameters to the kernel
 */
struct param_struct {
    union {
        struct {
            unsigned long page_size;            /*  0 */
            unsigned long nr_pages;             /*  4 */
            unsigned long ramdisk_size;         /*  8 */
            unsigned long flags;                /* 12 */
#define FLAG_READONLY   1
#define FLAG_RDLOAD     4
#define FLAG_RDPROMPT   8
            unsigned long rootdev;              /* 16 */
            unsigned long video_num_cols;       /* 20 */
            unsigned long video_num_rows;       /* 24 */
            unsigned long video_x;              /* 28 */
            unsigned long video_y;              /* 32 */
            unsigned long memc_control_reg;     /* 36 */
            unsigned char sounddefault;         /* 40 */
            unsigned char adfsdrives;           /* 41 */
            unsigned char bytes_per_char_h;     /* 42 */
            unsigned char bytes_per_char_v;     /* 43 */
            unsigned long pages_in_bank[4];     /* 44 */
            unsigned long pages_in_vram;        /* 60 */
            unsigned long initrd_start;         /* 64 */
            unsigned long initrd_size;          /* 68 */
            unsigned long rd_start;             /* 72 */
            unsigned long system_rev;           /* 76 */
            unsigned long system_serial_low;    /* 80 */
            unsigned long system_serial_high;   /* 84 */
            unsigned long mem_fclk_21285;       /* 88 */
        } s;
        char unused[256];
    } u1;
    union {
        char paths[8][128];
        struct {
            unsigned long magic;
            char n[1024 - sizeof(unsigned long)];
        } s;
    } u2;
    char commandline[COMMAND_LINE_SIZE];
};

static struct tag * __init memtag(struct tag *tag, unsigned long start, unsigned long size)
{
        tag = tag_next(tag);
        tag->hdr.tag = ATAG_MEM;
        tag->hdr.size = tag_size(tag_mem32);
        tag->u.mem.size = size;
        tag->u.mem.start = start;

        return tag;
}

static void __init build_tag_list(struct param_struct *params, void *taglist)
{
        struct tag *tag = taglist;

        if (params->u1.s.page_size != PAGE_SIZE) {
                pr_warn("Warning: bad configuration page, trying to continue\n");
                return;
        }

        printk(KERN_DEBUG "Converting old-style param struct to taglist\n");

#ifdef CONFIG_ARCH_NETWINDER
        if (params->u1.s.nr_pages != 0x02000 &&
            params->u1.s.nr_pages != 0x04000 &&
            params->u1.s.nr_pages != 0x08000 &&
            params->u1.s.nr_pages != 0x10000) {
                pr_warn("Warning: bad NeTTrom parameters detected, using defaults\n");

                params->u1.s.nr_pages = 0x1000; /* 16MB */
                params->u1.s.ramdisk_size = 0;
                params->u1.s.flags = FLAG_READONLY;
                params->u1.s.initrd_start = 0;
                params->u1.s.initrd_size = 0;
                params->u1.s.rd_start = 0;
        }
#endif

        tag->hdr.tag  = ATAG_CORE;
        tag->hdr.size = tag_size(tag_core);
        tag->u.core.flags = params->u1.s.flags & FLAG_READONLY;
        tag->u.core.pagesize = params->u1.s.page_size;
        tag->u.core.rootdev = params->u1.s.rootdev;

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_RAMDISK;
        tag->hdr.size = tag_size(tag_ramdisk);
        tag->u.ramdisk.flags = (params->u1.s.flags & FLAG_RDLOAD ? 1 : 0) |
                               (params->u1.s.flags & FLAG_RDPROMPT ? 2 : 0);
        tag->u.ramdisk.size  = params->u1.s.ramdisk_size;
        tag->u.ramdisk.start = params->u1.s.rd_start;

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_INITRD;
        tag->hdr.size = tag_size(tag_initrd);
        tag->u.initrd.start = params->u1.s.initrd_start;
        tag->u.initrd.size  = params->u1.s.initrd_size;

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_SERIAL;
        tag->hdr.size = tag_size(tag_serialnr);
        tag->u.serialnr.low = params->u1.s.system_serial_low;
        tag->u.serialnr.high = params->u1.s.system_serial_high;

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_REVISION;
        tag->hdr.size = tag_size(tag_revision);
        tag->u.revision.rev = params->u1.s.system_rev;

#ifdef CONFIG_ARCH_ACORN
        if (machine_is_riscpc()) {
                int i;
                for (i = 0; i < 4; i++)
                        tag = memtag(tag, PHYS_OFFSET + (i << 26),
                                 params->u1.s.pages_in_bank[i] * PAGE_SIZE);
        } else
#endif
        tag = memtag(tag, PHYS_OFFSET, params->u1.s.nr_pages * PAGE_SIZE);

#ifdef CONFIG_FOOTBRIDGE
        if (params->u1.s.mem_fclk_21285) {
                tag = tag_next(tag);
                tag->hdr.tag = ATAG_MEMCLK;
                tag->hdr.size = tag_size(tag_memclk);
                tag->u.memclk.fmemclk = params->u1.s.mem_fclk_21285;
        }
#endif

#ifdef CONFIG_ARCH_EBSA285
        if (machine_is_ebsa285()) {
                tag = tag_next(tag);
                tag->hdr.tag = ATAG_VIDEOTEXT;
                tag->hdr.size = tag_size(tag_videotext);
                tag->u.videotext.x            = params->u1.s.video_x;
                tag->u.videotext.y            = params->u1.s.video_y;
                tag->u.videotext.video_page   = 0;
                tag->u.videotext.video_mode   = 0;
                tag->u.videotext.video_cols   = params->u1.s.video_num_cols;
                tag->u.videotext.video_ega_bx = 0;
                tag->u.videotext.video_lines  = params->u1.s.video_num_rows;
                tag->u.videotext.video_isvga  = 1;
                tag->u.videotext.video_points = 8;
        }
#endif

#ifdef CONFIG_ARCH_ACORN
        tag = tag_next(tag);
        tag->hdr.tag = ATAG_ACORN;
        tag->hdr.size = tag_size(tag_acorn);
        tag->u.acorn.memc_control_reg = params->u1.s.memc_control_reg;
        tag->u.acorn.vram_pages       = params->u1.s.pages_in_vram;
        tag->u.acorn.sounddefault     = params->u1.s.sounddefault;
        tag->u.acorn.adfsdrives       = params->u1.s.adfsdrives;
#endif

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_CMDLINE;
        tag->hdr.size = (strlen(params->commandline) + 3 +
                         sizeof(struct tag_header)) >> 2;
        strcpy(tag->u.cmdline.cmdline, params->commandline);

        tag = tag_next(tag);
        tag->hdr.tag = ATAG_NONE;
        tag->hdr.size = 0;

        memmove(params, taglist, ((int)tag) - ((int)taglist) +
                                 sizeof(struct tag_header));
}

void __init convert_to_tag_list(struct tag *tags)
{
        struct param_struct *params = (struct param_struct *)tags;
        build_tag_list(params, &params->u2);
}