/*-
 * Copyright (c) 2004 Olivier Houchard
 * Copyright (c) 1994-1998 Mark Brinicombe.
 * Copyright (c) 1994 Brini.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_platform.h"
#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ctype.h>
#include <sys/linker.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#ifdef FDT
#include <sys/boot.h>
#endif

#include <machine/cpu.h>
#include <machine/machdep.h>
#include <machine/metadata.h>
#include <machine/vmparam.h>

#ifdef FDT
#include <contrib/libfdt/libfdt.h>
#include <dev/fdt/fdt_common.h>
#endif

#ifdef DDB
#include <ddb/ddb.h>
#endif

extern char end[];
static char *loader_envp;

#ifdef FDT
static char static_kenv[4096];

#define CMDLINE_GUARD "FreeBSD:"
#define LBABI_MAX_COMMAND_LINE 512
static char linux_command_line[LBABI_MAX_COMMAND_LINE + 1];
#endif

/*
 * Fake up a boot descriptor table
 */
 #define PRELOAD_PUSH_VALUE(type, value) do {           \
        *(type *)(preload_ptr + size) = (value);        \
        size += sizeof(type);                           \
} while (0)

 #define PRELOAD_PUSH_STRING(str) do {                  \
        uint32_t ssize;                                 \
        ssize = strlen(str) + 1;                        \
        PRELOAD_PUSH_VALUE(uint32_t, ssize);            \
        strcpy((char*)(preload_ptr + size), str);       \
        size += ssize;                                  \
        size = roundup(size, sizeof(u_long));           \
} while (0)

/* Build minimal set of metatda. */
static vm_offset_t
fake_preload_metadata(void *dtb_ptr, size_t dtb_size)
{
        vm_offset_t lastaddr;
        static char fake_preload[256];
        caddr_t preload_ptr;
        size_t size;

        lastaddr = (vm_offset_t)&end;
        preload_ptr = (caddr_t)&fake_preload[0];
        size = 0;

        PRELOAD_PUSH_VALUE(uint32_t, MODINFO_NAME);
        PRELOAD_PUSH_STRING("kernel");

        PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
        PRELOAD_PUSH_STRING(preload_kerntype);

        PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
        PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
        PRELOAD_PUSH_VALUE(uint64_t, VM_MIN_KERNEL_ADDRESS);

        PRELOAD_PUSH_VALUE(uint32_t, MODINFO_SIZE);
        PRELOAD_PUSH_VALUE(uint32_t, sizeof(size_t));
        PRELOAD_PUSH_VALUE(uint64_t,
                (size_t)((vm_offset_t)&end - VM_MIN_KERNEL_ADDRESS));

        if (dtb_ptr != NULL) {
                /* Copy DTB to KVA space and insert it into module chain. */
                lastaddr = roundup(lastaddr, sizeof(int));
                PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_DTBP);
                PRELOAD_PUSH_VALUE(uint32_t, sizeof(uint64_t));
                PRELOAD_PUSH_VALUE(uint64_t, (uint64_t)lastaddr);
                memmove_early((void *)lastaddr, dtb_ptr, dtb_size);
                lastaddr += dtb_size;
                lastaddr = roundup(lastaddr, sizeof(int));
        }
        /* End marker */
        PRELOAD_PUSH_VALUE(uint32_t, 0);
        PRELOAD_PUSH_VALUE(uint32_t, 0);

        preload_metadata = (caddr_t)(uintptr_t)fake_preload;

        /* Initialize preload_kmdp */
        preload_initkmdp(true);

        init_static_kenv(NULL, 0);

        return (lastaddr);
}

#ifdef FDT

/* Convert the U-Boot command line into FreeBSD kenv and boot options. */
static void
cmdline_set_env(char *cmdline, const char *guard)
{
        size_t guard_len;

        /* Skip leading spaces. */
        while (isspace(*cmdline))
                cmdline++;

        /* Test and remove guard. */
        if (guard != NULL && guard[0] != '\0') {
                guard_len  =  strlen(guard);
                if (strncasecmp(cmdline, guard, guard_len) != 0)
                        return;
                cmdline += guard_len;
        }

        boothowto |= boot_parse_cmdline(cmdline);
}

void
parse_fdt_bootargs(void)
{

        if (loader_envp == NULL && fdt_get_chosen_bootargs(linux_command_line,
            LBABI_MAX_COMMAND_LINE) == 0) {
                init_static_kenv(static_kenv, sizeof(static_kenv));
                cmdline_set_env(linux_command_line, CMDLINE_GUARD);
        }
}

#endif

#if defined(LINUX_BOOT_ABI) && defined(FDT)
static vm_offset_t
linux_parse_boot_param(struct arm64_bootparams *abp)
{
        struct fdt_header *dtb_ptr;
        size_t dtb_size;

        if (abp->modulep == 0)
                return (0);
        /* Test if modulep point to valid DTB. */
        dtb_ptr = (struct fdt_header *)abp->modulep;
        if (fdt_check_header(dtb_ptr) != 0)
                return (0);
        dtb_size = fdt_totalsize(dtb_ptr);
        return (fake_preload_metadata(dtb_ptr, dtb_size));
}

#endif

static vm_offset_t
freebsd_parse_boot_param(struct arm64_bootparams *abp)
{
        vm_offset_t lastaddr = 0;
#ifdef DDB
        vm_offset_t ksym_start;
        vm_offset_t ksym_end;
#endif

        if (abp->modulep == 0)
                return (0);

        preload_metadata = (caddr_t)(uintptr_t)(abp->modulep);

        /* Initialize preload_kmdp */
        preload_initkmdp(false);
        if (preload_kmdp == NULL)
                return (0);

        boothowto = MD_FETCH(preload_kmdp, MODINFOMD_HOWTO, int);
        loader_envp = MD_FETCH(preload_kmdp, MODINFOMD_ENVP, char *);
        init_static_kenv(loader_envp, 0);
        lastaddr = MD_FETCH(preload_kmdp, MODINFOMD_KERNEND, vm_offset_t);
#ifdef DDB
        ksym_start = MD_FETCH(preload_kmdp, MODINFOMD_SSYM, uintptr_t);
        ksym_end = MD_FETCH(preload_kmdp, MODINFOMD_ESYM, uintptr_t);
        db_fetch_ksymtab(ksym_start, ksym_end, 0);
#endif
        return (lastaddr);
}

vm_offset_t
parse_boot_param(struct arm64_bootparams *abp)
{
        vm_offset_t lastaddr;

#if defined(LINUX_BOOT_ABI) && defined(FDT)
        lastaddr = linux_parse_boot_param(abp);
        if (lastaddr != 0)
                return (lastaddr);
#endif
        lastaddr = freebsd_parse_boot_param(abp);
        if (lastaddr != 0)
                return (lastaddr);

        /* Fall back to hardcoded metadata. */
        lastaddr = fake_preload_metadata(NULL, 0);

        return (lastaddr);
}