/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * Copyright (c) 2004, 2006 Marcel Moolenaar
 * Copyright (c) 2014 The FreeBSD Foundation
 * 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 <string.h>
#include <sys/param.h>
#include <sys/reboot.h>
#include <sys/linker.h>
#include <sys/boot.h>
#include <machine/cpufunc.h>
#include <machine/elf.h>
#include <machine/metadata.h>
#include <machine/psl.h>

#include <efi.h>
#include <efilib.h>

#include "bootstrap.h"
#include "loader_efi.h"

#if defined(__amd64__)
#include <machine/specialreg.h>
#include "framebuffer.h"
#endif

#if defined(LOADER_FDT_SUPPORT)
#include <fdt_platform.h>
#endif

int bi_load(char *args, vm_offset_t *modulep, vm_offset_t *kernendp);

extern EFI_SYSTEM_TABLE *ST;

static const char howto_switches[] = "aCdrgDmphsv";
static int howto_masks[] = {
        RB_ASKNAME, RB_CDROM, RB_KDB, RB_DFLTROOT, RB_GDB, RB_MULTIPLE,
        RB_MUTE, RB_PAUSE, RB_SERIAL, RB_SINGLE, RB_VERBOSE
};

static int
bi_getboothowto(char *kargs)
{
        const char *sw;
        char *opts;
        char *console;
        int howto, i;

        howto = 0;

        /* Get the boot options from the environment first. */
        for (i = 0; howto_names[i].ev != NULL; i++) {
                if (getenv(howto_names[i].ev) != NULL)
                        howto |= howto_names[i].mask;
        }

        console = getenv("console");
        if (console != NULL) {
                if (strcmp(console, "comconsole") == 0)
                        howto |= RB_SERIAL;
                if (strcmp(console, "nullconsole") == 0)
                        howto |= RB_MUTE;
        }

        /* Parse kargs */
        if (kargs == NULL)
                return (howto);

        opts = strchr(kargs, '-');
        while (opts != NULL) {
                while (*(++opts) != '\0') {
                        sw = strchr(howto_switches, *opts);
                        if (sw == NULL)
                                break;
                        howto |= howto_masks[sw - howto_switches];
                }
                opts = strchr(opts, '-');
        }

        return (howto);
}

/*
 * Copy the environment into the load area starting at (addr).
 * Each variable is formatted as <name>=<value>, with a single nul
 * separating each variable, and a double nul terminating the environment.
 */
vm_offset_t
bi_copyenv(vm_offset_t start)
{
        struct env_var *ep;
        vm_offset_t addr, last;
        size_t len;

        addr = last = start;

        /* Traverse the environment. */
        for (ep = environ; ep != NULL; ep = ep->ev_next) {
                len = strlen(ep->ev_name);
                if ((size_t)archsw.arch_copyin(ep->ev_name, addr, len) != len)
                        break;
                addr += len;
                if (archsw.arch_copyin("=", addr, 1) != 1)
                        break;
                addr++;
                if (ep->ev_value != NULL) {
                        len = strlen(ep->ev_value);
                        if ((size_t)archsw.arch_copyin(ep->ev_value,
                            addr, len) != len)
                                break;
                        addr += len;
                }
                if (archsw.arch_copyin("", addr, 1) != 1)
                        break;
                last = ++addr;
        }

        if (archsw.arch_copyin("", last++, 1) != 1)
                last = start;
        return (last);
}

/*
 * 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)                                                  \
                archsw.arch_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)                                                  \
                archsw.arch_copyin(s, a, strlen(s) + 1);        \
        a += roundup(strlen(s) + 1, sizeof (ulong_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)                                                  \
                archsw.arch_copyin(&s, a, sizeof (s));          \
        a += roundup(sizeof (s), sizeof (ulong_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)                                                  \
                archsw.arch_copyin(mm->md_data, a, mm->md_size);        \
        a += roundup(mm->md_size, sizeof (ulong_t));            \
}

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

static vm_offset_t
bi_copymodules(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 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;
#if defined(__arm__)
                v -= __elfN(relocation_offset);
#endif
                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);
}

static int
bi_load_efi_data(struct preloaded_file *kfp)
{
        EFI_MEMORY_DESCRIPTOR *mm;
        EFI_PHYSICAL_ADDRESS addr;
        EFI_STATUS status;
        size_t efisz;
        UINTN efi_mapkey;
        UINTN mmsz, pages, retry, sz;
        UINT32 mmver;
        struct efi_map_header *efihdr;

#if defined(__amd64__)
        struct efi_fb efifb;

        if (efi_find_framebuffer(&efifb) == 0) {
                printf("EFI framebuffer information:\n");
                printf("addr, size     0x%lx, 0x%lx\n", efifb.fb_addr,
                    efifb.fb_size);
                printf("dimensions     %d x %d\n", efifb.fb_width,
                    efifb.fb_height);
                printf("stride         %d\n", efifb.fb_stride);
                printf("masks          0x%08x, 0x%08x, 0x%08x, 0x%08x\n",
                    efifb.fb_mask_red, efifb.fb_mask_green, efifb.fb_mask_blue,
                    efifb.fb_mask_reserved);

                file_addmetadata(kfp, MODINFOMD_EFI_FB, sizeof (efifb), &efifb);
        }
#endif

        efisz = (sizeof (struct efi_map_header) + 0xf) & ~0xf;

        /*
         * It is possible that the first call to ExitBootServices may change
         * the map key. Fetch a new map key and retry ExitBootServices in that
         * case.
         */
        for (retry = 2; retry > 0; retry--) {
                /*
                 * Allocate enough pages to hold the bootinfo block and the
                 * memory map EFI will return to us. The memory map has an
                 * unknown size, so we have to determine that first. Note that
                 * the AllocatePages call can itself modify the memory map, so
                 * we have to take that into account as well. The changes to
                 * the memory map are caused by splitting a range of free
                 * memory into two (AFAICT), so that one is marked as being
                 * loader data.
                 */
                sz = 0;
                BS->GetMemoryMap(&sz, NULL, &efi_mapkey, &mmsz, &mmver);
                sz += mmsz;
                sz = (sz + 0xf) & ~0xf;
                pages = EFI_SIZE_TO_PAGES(sz + efisz);
                status = BS->AllocatePages(AllocateAnyPages, EfiLoaderData,
                    pages, &addr);
                if (EFI_ERROR(status)) {
                        printf("%s: AllocatePages error %lu\n", __func__,
                            DECODE_ERROR(status));
                        return (ENOMEM);
                }

                /*
                 * Read the memory map and stash it after bootinfo. Align the
                 * memory map on a 16-byte boundary (the bootinfo block is page
                 * aligned).
                 */
                efihdr = (struct efi_map_header *)(uintptr_t)addr;
                mm = (void *)((uint8_t *)efihdr + efisz);
                sz = (EFI_PAGE_SIZE * pages) - efisz;

                status = BS->GetMemoryMap(&sz, mm, &efi_mapkey, &mmsz, &mmver);
                if (EFI_ERROR(status)) {
                        printf("%s: GetMemoryMap error %lu\n", __func__,
                            DECODE_ERROR(status));
                        return (EINVAL);
                }
                status = BS->ExitBootServices(IH, efi_mapkey);
                if (EFI_ERROR(status) == 0) {
                        efihdr->memory_size = sz;
                        efihdr->descriptor_size = mmsz;
                        efihdr->descriptor_version = mmver;
                        file_addmetadata(kfp, MODINFOMD_EFI_MAP, efisz + sz,
                            efihdr);
                        return (0);
                }
                BS->FreePages(addr, pages);
        }
        printf("ExitBootServices error %lu\n", DECODE_ERROR(status));
        return (EINVAL);
}

/*
 * 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_load(char *args, vm_offset_t *modulep, vm_offset_t *kernendp)
{
        struct preloaded_file *xp, *kfp;
        struct 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 defined(LOADER_FDT_SUPPORT)
        vm_offset_t dtbp;
        int dtb_size;
#endif
#if defined(__arm__)
        vm_offset_t vaddr;
        size_t i;
        /*
         * These metadata addreses must be converted for kernel after
         * relocation.
         */
        uint32_t                mdt[] = {
            MODINFOMD_SSYM, MODINFOMD_ESYM, MODINFOMD_KERNEND,
            MODINFOMD_ENVP,
#if defined(LOADER_FDT_SUPPORT)
            MODINFOMD_DTBP
#endif
        };
#endif

        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");
        archsw.arch_getdev((void**)(&rootdev), rootdevname, NULL);
        if (rootdev == NULL) {
                printf("Can't determine root device.\n");
                return (EINVAL);
        }

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

        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);

#if defined(LOADER_FDT_SUPPORT)
        /* Handle device tree blob */
        dtbp = addr;
        dtb_size = fdt_copy(addr);

        /* Pad to a page boundary */
        if (dtb_size)
                addr += roundup(dtb_size, PAGE_SIZE);
#endif

        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);
#if defined(LOADER_FDT_SUPPORT)
        if (dtb_size)
                file_addmetadata(kfp, MODINFOMD_DTBP, sizeof (dtbp), &dtbp);
        else
                pager_output("WARNING! Trying to fire up the kernel, but no "
                    "device tree blob found!\n");
#endif
        file_addmetadata(kfp, MODINFOMD_KERNEND, sizeof (kernend), &kernend);
        file_addmetadata(kfp, MODINFOMD_FW_HANDLE, sizeof (ST), &ST);

        bi_load_efi_data(kfp);

        /* Figure out the size and location of the metadata. */
        *modulep = addr;
        size = bi_copymodules(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));

#if defined(__arm__)
        *modulep -= __elfN(relocation_offset);

        /* Do relocation fixup on metadata of each module. */
        for (xp = file_findfile(NULL, NULL); xp != NULL; xp = xp->f_next) {
                for (i = 0; i < nitems(mdt); i++) {
                        md = file_findmetadata(xp, mdt[i]);
                        if (md) {
                                bcopy(md->md_data, &vaddr, sizeof (vaddr));
                                vaddr -= __elfN(relocation_offset);
                                bcopy(&vaddr, md->md_data, sizeof (vaddr));
                        }
                }
        }
#endif

        /* Copy module list and metadata. */
        (void) bi_copymodules(addr);

        return (0);
}