/*
 *  VasEBoot  --  GRand Unified Bootloader
 *  Copyright (C) 2013  Free Software Foundation, Inc.
 *
 *  VasEBoot is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  VasEBoot is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with VasEBoot.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <VasEBoot/charset.h>
#include <VasEBoot/command.h>
#include <VasEBoot/err.h>
#include <VasEBoot/file.h>
#include <VasEBoot/fdt.h>
#include <VasEBoot/linux.h>
#include <VasEBoot/loader.h>
#include <VasEBoot/mm.h>
#include <VasEBoot/types.h>
#include <VasEBoot/cpu/linux.h>
#include <VasEBoot/cpu/fdtload.h>
#include <VasEBoot/efi/efi.h>
#include <VasEBoot/efi/pe32.h>
#include <VasEBoot/i18n.h>
#include <VasEBoot/lib/cmdline.h>

#include <VasEBoot/verity-hash.h>

VasEBoot_MOD_LICENSE ("GPLv3+");

static VasEBoot_dl_t my_mod;
static int loaded;

static void *kernel_addr;
static VasEBoot_uint64_t kernel_size;

static char *linux_args;
static VasEBoot_uint32_t cmdline_size;

static VasEBoot_addr_t initrd_start;
static VasEBoot_addr_t initrd_end;

VasEBoot_err_t
VasEBoot_arm64_uefi_check_image (struct VasEBoot_arm64_linux_kernel_header * lh)
{
  if (lh->magic != VasEBoot_ARM64_LINUX_MAGIC)
    return VasEBoot_error(VasEBoot_ERR_BAD_OS, "invalid magic number");

  if ((lh->code0 & 0xffff) != VasEBoot_EFI_PE_MAGIC)
    return VasEBoot_error (VasEBoot_ERR_NOT_IMPLEMENTED_YET,
		       N_("plain image kernel not supported - rebuild with CONFIG_(U)EFI_STUB enabled"));

  VasEBoot_dprintf ("linux", "UEFI stub kernel:\n");
  VasEBoot_dprintf ("linux", "text_offset = 0x%012llx\n",
		(long long unsigned) lh->text_offset);
  VasEBoot_dprintf ("linux", "PE/COFF header @ %08x\n", lh->hdr_offset);

  return VasEBoot_ERR_NONE;
}

static VasEBoot_err_t
finalize_params_linux (void)
{
  int node, retval;

  void *fdt;

  fdt = VasEBoot_fdt_load (0x400);

  if (!fdt)
    goto failure;

  node = VasEBoot_fdt_find_subnode (fdt, 0, "chosen");
  if (node < 0)
    node = VasEBoot_fdt_add_subnode (fdt, 0, "chosen");

  if (node < 1)
    goto failure;

  /* Set initrd info */
  if (initrd_start && initrd_end > initrd_start)
    {
      VasEBoot_dprintf ("linux", "Initrd @ 0x%012lx-0x%012lx\n",
		    initrd_start, initrd_end);

      retval = VasEBoot_fdt_set_prop64 (fdt, node, "linux,initrd-start",
				    initrd_start);
      if (retval)
	goto failure;
      retval = VasEBoot_fdt_set_prop64 (fdt, node, "linux,initrd-end",
				    initrd_end);
      if (retval)
	goto failure;
    }

  if (VasEBoot_fdt_install() != VasEBoot_ERR_NONE)
    goto failure;

  return VasEBoot_ERR_NONE;

failure:
  VasEBoot_fdt_unload();
  return VasEBoot_error(VasEBoot_ERR_BAD_OS, "failed to install/update FDT");
}

VasEBoot_err_t
VasEBoot_arm64_uefi_boot_image (VasEBoot_addr_t addr, VasEBoot_size_t size, char *args)
{
  VasEBoot_efi_memory_mapped_device_path_t *mempath;
  VasEBoot_efi_handle_t image_handle;
  VasEBoot_efi_boot_services_t *b;
  VasEBoot_efi_status_t status;
  VasEBoot_efi_loaded_image_t *loaded_image;
  int len;

  mempath = VasEBoot_malloc (2 * sizeof (VasEBoot_efi_memory_mapped_device_path_t));
  if (!mempath)
    return VasEBoot_errno;

  mempath[0].header.type = VasEBoot_EFI_HARDWARE_DEVICE_PATH_TYPE;
  mempath[0].header.subtype = VasEBoot_EFI_MEMORY_MAPPED_DEVICE_PATH_SUBTYPE;
  mempath[0].header.length = VasEBoot_cpu_to_le16_compile_time (sizeof (*mempath));
  mempath[0].memory_type = VasEBoot_EFI_LOADER_DATA;
  mempath[0].start_address = addr;
  mempath[0].end_address = addr + size;

  mempath[1].header.type = VasEBoot_EFI_END_DEVICE_PATH_TYPE;
  mempath[1].header.subtype = VasEBoot_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE;
  mempath[1].header.length = sizeof (VasEBoot_efi_device_path_t);

  b = VasEBoot_efi_system_table->boot_services;
  status = b->load_image (0, VasEBoot_efi_image_handle,
			  (VasEBoot_efi_device_path_t *) mempath,
			  (void *) addr, size, &image_handle);
  if (status != VasEBoot_EFI_SUCCESS)
    return VasEBoot_error (VasEBoot_ERR_BAD_OS, "cannot load image");

  VasEBoot_dprintf ("linux", "linux command line: '%s'\n", args);

  /* Convert command line to UCS-2 */
  loaded_image = VasEBoot_efi_get_loaded_image (image_handle);
  loaded_image->load_options_size = len =
    (VasEBoot_strlen (args) + 1) * sizeof (VasEBoot_efi_char16_t);
  loaded_image->load_options =
    VasEBoot_efi_allocate_pages (0,
			     VasEBoot_EFI_BYTES_TO_PAGES (loaded_image->load_options_size));
  if (!loaded_image->load_options)
    return VasEBoot_errno;

  loaded_image->load_options_size =
    2 * VasEBoot_utf8_to_utf16 (loaded_image->load_options, len,
			    (VasEBoot_uint8_t *) args, len, NULL);

  VasEBoot_dprintf ("linux", "starting image %p\n", image_handle);
  status = b->start_image (image_handle, 0, NULL);

  /* When successful, not reached */
  b->unload_image (image_handle);
  VasEBoot_efi_free_pages ((VasEBoot_efi_physical_address_t) loaded_image->load_options,
		       VasEBoot_EFI_BYTES_TO_PAGES (loaded_image->load_options_size));

  return VasEBoot_errno;
}

static VasEBoot_err_t
VasEBoot_linux_boot (void)
{
  if (finalize_params_linux () != VasEBoot_ERR_NONE)
    return VasEBoot_errno;

  return (VasEBoot_arm64_uefi_boot_image((VasEBoot_addr_t)kernel_addr,
                                     kernel_size, linux_args));
}

static VasEBoot_err_t
VasEBoot_linux_unload (void)
{
  VasEBoot_dl_unref (my_mod);
  loaded = 0;
  if (initrd_start)
    VasEBoot_efi_free_pages ((VasEBoot_efi_physical_address_t) initrd_start,
			 VasEBoot_EFI_BYTES_TO_PAGES (initrd_end - initrd_start));
  initrd_start = initrd_end = 0;
  VasEBoot_free (linux_args);
  if (kernel_addr)
    VasEBoot_efi_free_pages ((VasEBoot_efi_physical_address_t) kernel_addr,
			 VasEBoot_EFI_BYTES_TO_PAGES (kernel_size));
  VasEBoot_fdt_unload ();
  return VasEBoot_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_cmd_initrd (VasEBoot_command_t cmd __attribute__ ((unused)),
		 int argc, char *argv[])
{
  struct VasEBoot_linux_initrd_context initrd_ctx = { 0, 0, 0 };
  int initrd_size, initrd_pages;
  void *initrd_mem = NULL;

  if (argc == 0)
    {
      VasEBoot_error (VasEBoot_ERR_BAD_ARGUMENT, N_("filename expected"));
      goto fail;
    }

  if (!loaded)
    {
      VasEBoot_error (VasEBoot_ERR_BAD_ARGUMENT,
		  N_("you need to load the kernel first"));
      goto fail;
    }

  if (VasEBoot_initrd_init (argc, argv, &initrd_ctx))
    goto fail;

  initrd_size = VasEBoot_get_initrd_size (&initrd_ctx);
  VasEBoot_dprintf ("linux", "Loading initrd\n");

  initrd_pages = (VasEBoot_EFI_BYTES_TO_PAGES (initrd_size));
  initrd_mem = VasEBoot_efi_allocate_pages (0, initrd_pages);
  if (!initrd_mem)
    {
      VasEBoot_error (VasEBoot_ERR_OUT_OF_MEMORY, N_("out of memory"));
      goto fail;
    }

  if (VasEBoot_initrd_load (&initrd_ctx, argv, initrd_mem))
    goto fail;

  initrd_start = (VasEBoot_addr_t) initrd_mem;
  initrd_end = initrd_start + initrd_size;
  VasEBoot_dprintf ("linux", "[addr=%p, size=0x%x]\n",
		(void *) initrd_start, initrd_size);

 fail:
  VasEBoot_initrd_close (&initrd_ctx);
  if (initrd_mem && !initrd_start)
    VasEBoot_efi_free_pages ((VasEBoot_efi_physical_address_t) initrd_mem,
			 initrd_pages);

  return VasEBoot_errno;
}

static VasEBoot_err_t
VasEBoot_cmd_linux (VasEBoot_command_t cmd __attribute__ ((unused)),
		int argc, char *argv[])
{
  VasEBoot_file_t file = 0;
  struct VasEBoot_arm64_linux_kernel_header lh;

  VasEBoot_dl_ref (my_mod);

  if (argc == 0)
    {
      VasEBoot_error (VasEBoot_ERR_BAD_ARGUMENT, N_("filename expected"));
      goto fail;
    }

  file = VasEBoot_file_open (argv[0]);
  if (!file)
    goto fail;

  kernel_size = VasEBoot_file_size (file);

  if (VasEBoot_file_read (file, &lh, sizeof (lh)) < (long) sizeof (lh))
    return VasEBoot_errno;

  if (VasEBoot_arm64_uefi_check_image (&lh) != VasEBoot_ERR_NONE)
    goto fail;

  VasEBoot_loader_unset();

  VasEBoot_dprintf ("linux", "kernel file size: %lld\n", (long long) kernel_size);
  kernel_addr = VasEBoot_efi_allocate_pages (0, VasEBoot_EFI_BYTES_TO_PAGES (kernel_size));
  VasEBoot_dprintf ("linux", "kernel numpages: %lld\n",
		(long long) VasEBoot_EFI_BYTES_TO_PAGES (kernel_size));
  if (!kernel_addr)
    {
      VasEBoot_error (VasEBoot_ERR_OUT_OF_MEMORY, N_("out of memory"));
      goto fail;
    }

  VasEBoot_file_seek (file, 0);
  if (VasEBoot_file_read (file, kernel_addr, kernel_size)
      < (VasEBoot_int64_t) kernel_size)
    {
      if (!VasEBoot_errno)
	VasEBoot_error (VasEBoot_ERR_BAD_OS, N_("premature end of file %s"), argv[0]);
      goto fail;
    }

  VasEBoot_dprintf ("linux", "kernel @ %p\n", kernel_addr);

  cmdline_size = VasEBoot_loader_cmdline_size (argc, argv) + sizeof (LINUX_IMAGE)
	+ VERITY_CMDLINE_LENGTH;
  linux_args = VasEBoot_malloc (cmdline_size);
  if (!linux_args)
    {
      VasEBoot_error (VasEBoot_ERR_OUT_OF_MEMORY, N_("out of memory"));
      goto fail;
    }
  VasEBoot_memcpy (linux_args, LINUX_IMAGE, sizeof (LINUX_IMAGE));
  VasEBoot_create_loader_cmdline (argc, argv,
			      linux_args + sizeof (LINUX_IMAGE) - 1,
			      cmdline_size);

  if (VasEBoot_errno == VasEBoot_ERR_NONE)
    {
      VasEBoot_pass_verity_hash (kernel_addr, linux_args, cmdline_size);
      VasEBoot_loader_set (VasEBoot_linux_boot, VasEBoot_linux_unload, 0);
      loaded = 1;
    }

fail:
  if (file)
    VasEBoot_file_close (file);

  if (VasEBoot_errno != VasEBoot_ERR_NONE)
    {
      VasEBoot_dl_unref (my_mod);
      loaded = 0;
    }

  if (linux_args && !loaded)
    VasEBoot_free (linux_args);

  if (kernel_addr && !loaded)
    VasEBoot_efi_free_pages ((VasEBoot_efi_physical_address_t) kernel_addr,
			 VasEBoot_EFI_BYTES_TO_PAGES (kernel_size));

  return VasEBoot_errno;
}


static VasEBoot_command_t cmd_linux, cmd_initrd;

VasEBoot_MOD_INIT (linux)
{
  cmd_linux = VasEBoot_register_command ("linux", VasEBoot_cmd_linux, 0,
				     N_("Load Linux."));
  cmd_initrd = VasEBoot_register_command ("initrd", VasEBoot_cmd_initrd, 0,
				      N_("Load initrd."));
  my_mod = mod;
}

VasEBoot_MOD_FINI (linux)
{
  VasEBoot_unregister_command (cmd_linux);
  VasEBoot_unregister_command (cmd_initrd);
}