/*
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * 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 <sys/cdefs.h>

#include <stand.h>
#include <sys/param.h>
#include <sys/reboot.h>
#include <sys/linker.h>
#include <i386/include/bootinfo.h>
#include <machine/cpufunc.h>
#include <machine/psl.h>
#include <machine/specialreg.h>

#include "bootstrap.h"
#include "libuserboot.h"

/*
 * Copy module-related data into the load area, where it can be
 * used as a directory for loaded modules.
 *
 * Module data is presented in a self-describing format.  Each datum
 * is preceded by a 32-bit identifier and a 32-bit size field.
 *
 * Currently, the following data are saved:
 *
 * MOD_NAME     (variable)              module name (string)
 * MOD_TYPE     (variable)              module type (string)
 * MOD_ARGS     (variable)              module parameters (string)
 * MOD_ADDR     sizeof(vm_offset_t)     module load address
 * MOD_SIZE     sizeof(size_t)          module size
 * MOD_METADATA (variable)              type-specific metadata
 */
#define COPY32(v, a, c) {                       \
    uint32_t    x = (v);                        \
    if (c)                                      \
        CALLBACK(copyin, &x, a, sizeof (x));    \
    a += sizeof (x);                            \
}

#define MOD_STR(t, a, s, c) {                   \
    COPY32(t, a, c);                            \
    COPY32(strlen(s) + 1, a, c);                \
    if (c)                                      \
        CALLBACK(copyin, s, a, strlen(s) + 1);  \
    a += roundup(strlen(s) + 1, sizeof (uint64_t));\
}

#define MOD_NAME(a, s, c)       MOD_STR(MODINFO_NAME, a, s, c)
#define MOD_TYPE(a, s, c)       MOD_STR(MODINFO_TYPE, a, s, c)
#define MOD_ARGS(a, s, c)       MOD_STR(MODINFO_ARGS, a, s, c)

#define MOD_VAR(t, a, s, c) {                   \
    COPY32(t, a, c);                            \
    COPY32(sizeof (s), a, c);                   \
    if (c)                                      \
        CALLBACK(copyin, &s, a, sizeof (s));    \
    a += roundup(sizeof (s), sizeof (uint64_t));        \
}

#define MOD_ADDR(a, s, c)       MOD_VAR(MODINFO_ADDR, a, s, c)
#define MOD_SIZE(a, s, c)       MOD_VAR(MODINFO_SIZE, a, s, c)

#define MOD_METADATA(a, mm, c) {                \
    COPY32(MODINFO_METADATA | mm->md_type, a, c); \
    COPY32(mm->md_size, a, c);                  \
    if (c)                                      \
        CALLBACK(copyin, mm->md_data, a, mm->md_size);    \
    a += roundup(mm->md_size, sizeof (uint64_t));\
}

#define MOD_END(a, c) {                         \
    COPY32(MODINFO_END, a, c);                  \
    COPY32(0, a, c);                            \
}

static vm_offset_t
bi_copymodules64(vm_offset_t addr)
{
        struct preloaded_file   *fp;
        struct file_metadata    *md;
        int                     c;
        uint64_t                v;

        c = addr != 0;
        /* start with the first module on the list, should be the kernel */
        for (fp = file_findfile(NULL, NULL); fp != NULL; fp = fp->f_next) {

                MOD_NAME(addr, fp->f_name, c);  /* this field must come first */
                MOD_TYPE(addr, fp->f_type, c);
                if (fp->f_args)
                        MOD_ARGS(addr, fp->f_args, c);
                v = fp->f_addr;
                MOD_ADDR(addr, v, c);
                v = fp->f_size;
                MOD_SIZE(addr, v, c);
                for (md = fp->f_metadata; md != NULL; md = md->md_next)
                        if (!(md->md_type & MODINFOMD_NOCOPY))
                                MOD_METADATA(addr, md, c);
        }
        MOD_END(addr, c);
        return (addr);
}

/*
 * Check to see if this CPU supports long mode.
 */
static int
bi_checkcpu(void)
{
#if 0
        char *cpu_vendor;
        int vendor[3];
        int eflags, regs[4];

        /* Check for presence of "cpuid". */
        eflags = read_eflags();
        write_eflags(eflags ^ PSL_ID);
        if (!((eflags ^ read_eflags()) & PSL_ID))
                return (0);

        /* Fetch the vendor string. */
        do_cpuid(0, regs);
        vendor[0] = regs[1];
        vendor[1] = regs[3];
        vendor[2] = regs[2];
        cpu_vendor = (char *)vendor;

        /* Check for vendors that support AMD features. */
        if (strncmp(cpu_vendor, INTEL_VENDOR_ID, 12) != 0 &&
            strncmp(cpu_vendor, AMD_VENDOR_ID, 12) != 0 &&
            strncmp(cpu_vendor, CENTAUR_VENDOR_ID, 12) != 0)
                return (0);

        /* Has to support AMD features. */
        do_cpuid(0x80000000, regs);
        if (!(regs[0] >= 0x80000001))
                return (0);

        /* Check for long mode. */
        do_cpuid(0x80000001, regs);
        return (regs[3] & AMDID_LM);
#else
        return (1);
#endif
}

/*
 * Load the information expected by an amd64 kernel.
 *
 * - The 'boothowto' argument is constructed
 * - The 'bootdev' argument is constructed
 * - The 'bootinfo' struct is constructed, and copied into the kernel space.
 * - The kernel environment is copied into kernel space.
 * - Module metadata are formatted and placed in kernel space.
 */
int
bi_load64(char *args, vm_offset_t *modulep, vm_offset_t *kernendp)
{
        struct preloaded_file   *xp, *kfp;
        struct userboot_devdesc *rootdev;
        struct file_metadata    *md;
        vm_offset_t             addr;
        uint64_t                kernend;
        uint64_t                envp;
        vm_offset_t             size;
        char                    *rootdevname;
        int                     howto;

        if (!bi_checkcpu()) {
                printf("CPU doesn't support long mode\n");
                return (EINVAL);
        }

        howto = bi_getboothowto(args);

        /*
         * Allow the environment variable 'rootdev' to override the supplied
         * device. This should perhaps go to MI code and/or have $rootdev
         * tested/set by MI code before launching the kernel.
         */
        rootdevname = getenv("rootdev");
        (void) userboot_getdev((void **)(&rootdev), rootdevname, NULL);
        if (rootdev == NULL) {          /* bad $rootdev/$currdev */
                printf("can't determine root device\n");
                return (EINVAL);
        }

        /* Try reading the /etc/fstab file to select the root device */
        (void) getrootmount(userboot_fmtdev((void *)rootdev));

        /* find the last module in the chain */
        addr = 0;
        for (xp = file_findfile(NULL, NULL); xp != NULL; xp = xp->f_next) {
                if (addr < (xp->f_addr + xp->f_size))
                        addr = xp->f_addr + xp->f_size;
        }
        /* pad to a page boundary */
        addr = roundup(addr, PAGE_SIZE);

        /* copy our environment */
        envp = addr;
        addr = bi_copyenv(addr);

        /* pad to a page boundary */
        addr = roundup(addr, PAGE_SIZE);

        kfp = file_findfile(NULL, "elf kernel");
        if (kfp == NULL)
                kfp = file_findfile(NULL, "elf64 kernel");
        if (kfp == NULL)
                panic("can't find kernel file");
        kernend = 0;    /* fill it in later */
        file_addmetadata(kfp, MODINFOMD_HOWTO, sizeof (howto), &howto);
        file_addmetadata(kfp, MODINFOMD_ENVP, sizeof (envp), &envp);
        file_addmetadata(kfp, MODINFOMD_KERNEND, sizeof (kernend), &kernend);
        bios_addsmapdata(kfp);

        /* Figure out the size and location of the metadata */
        *modulep = addr;
        size = bi_copymodules64(0);
        kernend = roundup(addr + size, PAGE_SIZE);
        *kernendp = kernend;

        /* patch MODINFOMD_KERNEND */
        md = file_findmetadata(kfp, MODINFOMD_KERNEND);
        bcopy(&kernend, md->md_data, sizeof (kernend));

        /* copy module list and metadata */
        (void) bi_copymodules64(addr);

        return (0);
}