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[PATCH] Add linuxefi module


From: Lubomir Rintel
Subject: [PATCH] Add linuxefi module
Date: Tue, 21 Jan 2014 00:28:08 +0100

From: Matthew Garrett <address@hidden>

This adds linuxefi module that provides a way to load Linux kernel and RAM disk
image via EFI services with linuxefi and initrdefi commands, analogous to linux
and initrd commands.

address@hidden: Clarify the commit message]
address@hidden: Add Changelog]
---
Hi,

this is taken from Fedora (and RHEL) package as it is. I've only done minor 
changes (described in commit message).

Please have a look and let me know if there's anything I could do to have his 
mainlined, so that we can get rid of the pile of patches we ship in Fedora.
Other Linux distributions interested in Linux on EFI support may find this 
useful too.

Thank you!
Lubo

 ChangeLog                         |   9 +
 grub-core/Makefile.core.def       |   8 +
 grub-core/kern/efi/mm.c           |  32 ++++
 grub-core/loader/i386/efi/linux.c | 371 ++++++++++++++++++++++++++++++++++++++
 include/grub/efi/efi.h            |   3 +
 include/grub/i386/linux.h         |   1 +
 6 files changed, 424 insertions(+)
 create mode 100644 grub-core/loader/i386/efi/linux.c

diff --git a/ChangeLog b/ChangeLog
index 10abfe2..432c786 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2014-01-20  Matthew Garrett  <address@hidden>
+
+       * grub-core/Makefile.core.def: Add linuxefi module.
+       * grub-core/kern/efi/mm.c (grub_efi_allocate_pages_max): Add.
+       * grub-core/loader/i386/efi/linux.c: Add.
+       * include/grub/efi/efi.h: Prototype for grub_efi_allocate_pages_max.
+       * include/grub/i386/linux.h (struct linux_kernel_header): Add
+       handover_offset.
+
 2014-01-19  Colin Watson  <address@hidden>
 
        * grub-core/osdep/freebsd/hostdisk.c (grub_util_fd_open): Ignore
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 42443bc..ec46506 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1706,6 +1706,14 @@ module = {
 };
 
 module = {
+  name = linuxefi;
+  efi = loader/i386/efi/linux.c;
+  efi = lib/cmdline.c;
+  enable = i386_efi;
+  enable = x86_64_efi;
+};
+
+module = {
   name = chain;
   efi = loader/efi/chainloader.c;
   i386_pc = loader/i386/pc/chainloader.c;
diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
index be37afd..ddeca60 100644
--- a/grub-core/kern/efi/mm.c
+++ b/grub-core/kern/efi/mm.c
@@ -49,6 +49,38 @@ static grub_efi_uintn_t finish_desc_size;
 static grub_efi_uint32_t finish_desc_version;
 int grub_efi_is_finished = 0;
 
+/* Allocate pages below a specified address */
+void *
+grub_efi_allocate_pages_max (grub_efi_physical_address_t max,
+                            grub_efi_uintn_t pages)
+{
+  grub_efi_status_t status;
+  grub_efi_boot_services_t *b;
+  grub_efi_physical_address_t address = max;
+
+  if (max > 0xffffffff)
+    return 0;
+
+  b = grub_efi_system_table->boot_services;
+  status = efi_call_4 (b->allocate_pages, GRUB_EFI_ALLOCATE_MAX_ADDRESS, 
GRUB_EFI_LOADER_DATA, pages, &address);
+
+  if (status != GRUB_EFI_SUCCESS)
+    return 0;
+
+  if (address == 0)
+    {
+      /* Uggh, the address 0 was allocated... This is too annoying,
+        so reallocate another one.  */
+      address = max;
+      status = efi_call_4 (b->allocate_pages, GRUB_EFI_ALLOCATE_MAX_ADDRESS, 
GRUB_EFI_LOADER_DATA, pages, &address);
+      grub_efi_free_pages (0, pages);
+      if (status != GRUB_EFI_SUCCESS)
+       return 0;
+    }
+
+  return (void *) ((grub_addr_t) address);
+}
+
 /* Allocate pages. Return the pointer to the first of allocated pages.  */
 void *
 grub_efi_allocate_pages (grub_efi_physical_address_t address,
diff --git a/grub-core/loader/i386/efi/linux.c 
b/grub-core/loader/i386/efi/linux.c
new file mode 100644
index 0000000..b79e632
--- /dev/null
+++ b/grub-core/loader/i386/efi/linux.c
@@ -0,0 +1,371 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2012  Free Software Foundation, Inc.
+ *
+ *  GRUB 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.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/loader.h>
+#include <grub/file.h>
+#include <grub/err.h>
+#include <grub/types.h>
+#include <grub/mm.h>
+#include <grub/cpu/linux.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+#include <grub/lib/cmdline.h>
+#include <grub/efi/efi.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static grub_dl_t my_mod;
+static int loaded;
+static void *kernel_mem;
+static grub_uint64_t kernel_size;
+static grub_uint8_t *initrd_mem;
+static grub_uint32_t handover_offset;
+struct linux_kernel_params *params;
+static char *linux_cmdline;
+
+#define BYTES_TO_PAGES(bytes)   (((bytes) + 0xfff) >> 12)
+
+#define SHIM_LOCK_GUID \
+  { 0x605dab50, 0xe046, 0x4300, {0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 
0x23} }
+
+struct grub_efi_shim_lock
+{
+  grub_efi_status_t (*verify) (void *buffer, grub_uint32_t size);
+};
+typedef struct grub_efi_shim_lock grub_efi_shim_lock_t;
+
+static grub_efi_boolean_t
+grub_linuxefi_secure_validate (void *data, grub_uint32_t size)
+{
+  grub_efi_guid_t guid = SHIM_LOCK_GUID;
+  grub_efi_shim_lock_t *shim_lock;
+
+  shim_lock = grub_efi_locate_protocol(&guid, NULL);
+
+  if (!shim_lock)
+    return 1;
+
+  if (shim_lock->verify(data, size) == GRUB_EFI_SUCCESS)
+    return 1;
+
+  return 0;
+}
+
+typedef void(*handover_func)(void *, grub_efi_system_table_t *, struct 
linux_kernel_params *);
+
+static grub_err_t
+grub_linuxefi_boot (void)
+{
+  handover_func hf;
+  int offset = 0;
+
+#ifdef __x86_64__
+  offset = 512;
+#endif
+
+  hf = (handover_func)((char *)kernel_mem + handover_offset + offset);
+
+  asm volatile ("cli");
+
+  hf (grub_efi_image_handle, grub_efi_system_table, params);
+
+  /* Not reached */
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_linuxefi_unload (void)
+{
+  grub_dl_unref (my_mod);
+  loaded = 0;
+  if (initrd_mem)
+    grub_efi_free_pages((grub_efi_physical_address_t)initrd_mem, 
BYTES_TO_PAGES(params->ramdisk_size));
+  if (linux_cmdline)
+    grub_efi_free_pages((grub_efi_physical_address_t)linux_cmdline, 
BYTES_TO_PAGES(params->cmdline_size + 1));
+  if (kernel_mem)
+    grub_efi_free_pages((grub_efi_physical_address_t)kernel_mem, 
BYTES_TO_PAGES(kernel_size));
+  if (params)
+    grub_efi_free_pages((grub_efi_physical_address_t)params, 
BYTES_TO_PAGES(16384));
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
+                 int argc, char *argv[])
+{
+  grub_file_t *files = 0;
+  int i, nfiles = 0;
+  grub_size_t size = 0;
+  grub_uint8_t *ptr;
+
+  if (argc == 0)
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
+      goto fail;
+    }
+
+  if (!loaded)
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("you need to load the kernel 
first"));
+      goto fail;
+    }
+
+  files = grub_zalloc (argc * sizeof (files[0]));
+  if (!files)
+    goto fail;
+
+  for (i = 0; i < argc; i++)
+    {
+      grub_file_filter_disable_compression ();
+      files[i] = grub_file_open (argv[i]);
+      if (! files[i])
+        goto fail;
+      nfiles++;
+      size += ALIGN_UP (grub_file_size (files[i]), 4);
+    }
+
+  initrd_mem = grub_efi_allocate_pages_max (0x3fffffff, BYTES_TO_PAGES(size));
+
+  if (!initrd_mem)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate initrd"));
+      goto fail;
+    }
+
+  params->ramdisk_size = size;
+  params->ramdisk_image = (grub_uint32_t)(grub_uint64_t) initrd_mem;
+
+  ptr = initrd_mem;
+
+  for (i = 0; i < nfiles; i++)
+    {
+      grub_ssize_t cursize = grub_file_size (files[i]);
+      if (grub_file_read (files[i], ptr, cursize) != cursize)
+        {
+          if (!grub_errno)
+            grub_error (GRUB_ERR_FILE_READ_ERROR, N_("premature end of file 
%s"),
+                        argv[i]);
+          goto fail;
+        }
+      ptr += cursize;
+      grub_memset (ptr, 0, ALIGN_UP_OVERHEAD (cursize, 4));
+      ptr += ALIGN_UP_OVERHEAD (cursize, 4);
+    }
+
+  params->ramdisk_size = size;
+
+ fail:
+  for (i = 0; i < nfiles; i++)
+    grub_file_close (files[i]);
+  grub_free (files);
+
+  if (initrd_mem && grub_errno)
+    grub_efi_free_pages((grub_efi_physical_address_t)initrd_mem, 
BYTES_TO_PAGES(size));
+
+  return grub_errno;
+}
+
+static grub_err_t
+grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
+               int argc, char *argv[])
+{
+  grub_file_t file = 0;
+  struct linux_kernel_header lh;
+  grub_ssize_t len, start, filelen;
+  void *kernel;
+
+  grub_dl_ref (my_mod);
+
+  if (argc == 0)
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
+      goto fail;
+    }
+
+  file = grub_file_open (argv[0]);
+  if (! file)
+    goto fail;
+
+  filelen = grub_file_size (file);
+
+  kernel = grub_malloc(filelen);
+
+  if (!kernel)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("cannot allocate kernel buffer"));
+      goto fail;
+    }
+
+  if (grub_file_read (file, kernel, filelen) != filelen)
+    {
+      grub_error (GRUB_ERR_FILE_READ_ERROR, N_("Can't read kernel %s"), 
argv[0]);
+      goto fail;
+    }
+
+  if (! grub_linuxefi_secure_validate (kernel, filelen))
+    {
+      grub_error (GRUB_ERR_INVALID_COMMAND, N_("%s has invalid signature"), 
argv[0]);
+      grub_free (kernel);
+      goto fail;
+    }
+
+  grub_file_seek (file, 0);
+
+  grub_free(kernel);
+
+  params = grub_efi_allocate_pages_max (0x3fffffff, BYTES_TO_PAGES(16384));
+
+  if (! params)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate kernel parameters");
+      goto fail;
+    }
+
+  memset (params, 0, 16384);
+
+  if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh))
+    {
+      if (!grub_errno)
+       grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
+                   argv[0]);
+      goto fail;
+    }
+
+  if (lh.boot_flag != grub_cpu_to_le16 (0xaa55))
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("invalid magic number"));
+      goto fail;
+    }
+
+  if (lh.setup_sects > GRUB_LINUX_MAX_SETUP_SECTS)
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("too many setup sectors"));
+      goto fail;
+    }
+
+  if (lh.version < grub_cpu_to_le16 (0x020b))
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("kernel too old"));
+      goto fail;
+    }
+
+  if (!lh.handover_offset)
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("kernel doesn't support EFI handover"));
+      goto fail;
+    }
+
+  linux_cmdline = grub_efi_allocate_pages_max(0x3fffffff,
+                                        BYTES_TO_PAGES(lh.cmdline_size + 1));
+
+  if (!linux_cmdline)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate cmdline"));
+      goto fail;
+    }
+
+  grub_memcpy (linux_cmdline, LINUX_IMAGE, sizeof (LINUX_IMAGE));
+  grub_create_loader_cmdline (argc, argv,
+                              linux_cmdline + sizeof (LINUX_IMAGE) - 1,
+                             lh.cmdline_size - (sizeof (LINUX_IMAGE) - 1));
+
+  lh.cmd_line_ptr = (grub_uint32_t)(grub_uint64_t)linux_cmdline;
+
+  handover_offset = lh.handover_offset;
+
+  start = (lh.setup_sects + 1) * 512;
+  len = grub_file_size(file) - start;
+
+  kernel_mem = grub_efi_allocate_pages(lh.pref_address,
+                                      BYTES_TO_PAGES(lh.init_size));
+
+  if (!kernel_mem)
+    kernel_mem = grub_efi_allocate_pages_max(0x3fffffff,
+                                            BYTES_TO_PAGES(lh.init_size));
+
+  if (!kernel_mem)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate kernel"));
+      goto fail;
+    }
+
+  if (grub_file_seek (file, start) == (grub_off_t) -1)
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
+                 argv[0]);
+      goto fail;
+    }
+
+  if (grub_file_read (file, kernel_mem, len) != len && !grub_errno)
+    {
+      grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
+                 argv[0]);
+    }
+
+  if (grub_errno == GRUB_ERR_NONE)
+    {
+      grub_loader_set (grub_linuxefi_boot, grub_linuxefi_unload, 0);
+      loaded = 1;
+      lh.code32_start = (grub_uint32_t)(grub_uint64_t) kernel_mem;
+    }
+
+  memcpy(params, &lh, 2 * 512);
+
+  params->type_of_loader = 0x21;
+
+ fail:
+
+  if (file)
+    grub_file_close (file);
+
+  if (grub_errno != GRUB_ERR_NONE)
+    {
+      grub_dl_unref (my_mod);
+      loaded = 0;
+    }
+
+  if (linux_cmdline && !loaded)
+    grub_efi_free_pages((grub_efi_physical_address_t)linux_cmdline, 
BYTES_TO_PAGES(lh.cmdline_size + 1));
+
+  if (kernel_mem && !loaded)
+    grub_efi_free_pages((grub_efi_physical_address_t)kernel_mem, 
BYTES_TO_PAGES(kernel_size));
+
+  if (params && !loaded)
+    grub_efi_free_pages((grub_efi_physical_address_t)params, 
BYTES_TO_PAGES(16384));
+
+  return grub_errno;
+}
+
+static grub_command_t cmd_linux, cmd_initrd;
+
+GRUB_MOD_INIT(linuxefi)
+{
+  cmd_linux =
+    grub_register_command ("linuxefi", grub_cmd_linux,
+                           0, N_("Load Linux."));
+  cmd_initrd =
+    grub_register_command ("initrdefi", grub_cmd_initrd,
+                           0, N_("Load initrd."));
+  my_mod = mod;
+}
+
+GRUB_MOD_FINI(linuxefi)
+{
+  grub_unregister_command (cmd_linux);
+  grub_unregister_command (cmd_initrd);
+}
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 489cf9e..9370fd5 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -40,6 +40,9 @@ void EXPORT_FUNC(grub_efi_stall) (grub_efi_uintn_t 
microseconds);
 void *
 EXPORT_FUNC(grub_efi_allocate_pages) (grub_efi_physical_address_t address,
                                      grub_efi_uintn_t pages);
+void *
+EXPORT_FUNC(grub_efi_allocate_pages_max) (grub_efi_physical_address_t max,
+                                         grub_efi_uintn_t pages);
 void EXPORT_FUNC(grub_efi_free_pages) (grub_efi_physical_address_t address,
                                       grub_efi_uintn_t pages);
 int
diff --git a/include/grub/i386/linux.h b/include/grub/i386/linux.h
index da0ca3b..fc36bda 100644
--- a/include/grub/i386/linux.h
+++ b/include/grub/i386/linux.h
@@ -139,6 +139,7 @@ struct linux_kernel_header
   grub_uint64_t setup_data;
   grub_uint64_t pref_address;
   grub_uint32_t init_size;
+  grub_uint32_t handover_offset;
 } GRUB_PACKED;
 
 /* Boot parameters for Linux based on 2.6.12. This is used by the setup
-- 
1.8.3.1




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