grub2/0253-Add-support-for-Linux-EFI-stub-loading-on-arm-archit.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Mon, 15 Apr 2024 11:19:31 -0600
Subject: [PATCH] Add support for Linux EFI stub loading on arm architectures

---
 grub-core/loader/arm64/xen_boot.c |   1 -
 grub-core/loader/efi/linux.c      | 116 ++++++++++++++++++--------------------
 include/grub/efi/efi.h            |  28 ++++++++-
 3 files changed, 80 insertions(+), 65 deletions(-)

diff --git a/grub-core/loader/arm64/xen_boot.c b/grub-core/loader/arm64/xen_boot.c
index 26e1472c9d2..9838a0f878b 100644
--- a/grub-core/loader/arm64/xen_boot.c
+++ b/grub-core/loader/arm64/xen_boot.c
@@ -252,7 +252,6 @@ xen_boot (void)
     return err;
 
   return grub_arch_efi_linux_boot_image (xen_hypervisor->start,
-					  xen_hypervisor->size,
 					  xen_hypervisor->cmdline);
 }
 
diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
index 44587df3858..8742e303d85 100644
--- a/grub-core/loader/efi/linux.c
+++ b/grub-core/loader/efi/linux.c
@@ -28,6 +28,7 @@
 #include <grub/efi/efi.h>
 #include <grub/efi/fdtload.h>
 #include <grub/efi/memory.h>
+#include <grub/efi/linux.h>
 #include <grub/efi/pe32.h>
 #include <grub/efi/linux.h>
 #include <grub/efi/sb.h>
@@ -42,6 +43,7 @@ static int loaded;
 
 static void *kernel_addr;
 static grub_uint64_t kernel_size;
+static grub_uint32_t handover_offset;
 
 static char *linux_args;
 static grub_uint32_t cmdline_size;
@@ -94,7 +96,7 @@ static grub_efi_load_file2_t initrd_lf2 = {
 typedef void (*handover_func) (void *, grub_efi_system_table_t *, void *);
 
 grub_err_t
-grub_efi_linux_boot (void *kernel_address, grub_off_t handover_offset,
+grub_efi_linux_boot (void *kernel_address, grub_off_t ho_offset,
 		     void *kernel_params)
 {
   grub_efi_loaded_image_t *loaded_image = NULL;
@@ -117,8 +119,8 @@ grub_efi_linux_boot (void *kernel_address, grub_off_t handover_offset,
     grub_dprintf ("linux", "Loaded Image base address could not be set\n");
 
   grub_dprintf ("linux", "kernel_address: %p handover_offset: %p params: %p\n",
-		kernel_address, (void *)(grub_efi_uintn_t)handover_offset, kernel_params);
-  hf = (handover_func)((char *)kernel_address + handover_offset + offset);
+		kernel_address, (void *)(grub_efi_uintn_t)ho_offset, kernel_params);
+  hf = (handover_func)((char *)kernel_address + ho_offset + offset);
   hf (grub_efi_image_handle, grub_efi_system_table, kernel_params);
 
   return GRUB_ERR_BUG;
@@ -178,7 +180,8 @@ grub_arch_efi_linux_load_image_header (grub_file_t file,
 static grub_err_t
 finalize_params_linux (void)
 {
-  int node, retval;
+  grub_efi_loaded_image_t *loaded_image = NULL;
+  int node, retval, len;
 
   void *fdt;
 
@@ -213,79 +216,65 @@ finalize_params_linux (void)
   if (grub_fdt_install() != GRUB_ERR_NONE)
     goto failure;
 
-  return GRUB_ERR_NONE;
-
-failure:
-  grub_fdt_unload();
-  return grub_error(GRUB_ERR_BAD_OS, "failed to install/update FDT");
-}
-#endif
-
-grub_err_t
-grub_arch_efi_linux_boot_image (grub_addr_t addr, grub_size_t size, char *args)
-{
-  grub_efi_memory_mapped_device_path_t *mempath;
-  grub_efi_handle_t image_handle;
-  grub_efi_boot_services_t *b;
-  grub_efi_status_t status;
-  grub_efi_loaded_image_t *loaded_image;
-  int len;
-
-  mempath = grub_malloc (2 * sizeof (grub_efi_memory_mapped_device_path_t));
-  if (!mempath)
-    return grub_errno;
-
-  mempath[0].header.type = GRUB_EFI_HARDWARE_DEVICE_PATH_TYPE;
-  mempath[0].header.subtype = GRUB_EFI_MEMORY_MAPPED_DEVICE_PATH_SUBTYPE;
-  mempath[0].header.length = grub_cpu_to_le16_compile_time (sizeof (*mempath));
-  mempath[0].memory_type = GRUB_EFI_LOADER_DATA;
-  mempath[0].start_address = addr;
-  mempath[0].end_address = addr + size;
-
-  mempath[1].header.type = GRUB_EFI_END_DEVICE_PATH_TYPE;
-  mempath[1].header.subtype = GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE;
-  mempath[1].header.length = sizeof (grub_efi_device_path_t);
-
-  b = grub_efi_system_table->boot_services;
-  status = b->load_image (0, grub_efi_image_handle,
-			  (grub_efi_device_path_t *) mempath,
-			  (void *) addr, size, &image_handle);
-  if (status != GRUB_EFI_SUCCESS)
-    return grub_error (GRUB_ERR_BAD_OS, "cannot load image");
-
-  grub_dprintf ("linux", "linux command line: '%s'\n", args);
+  grub_dprintf ("linux", "Installed/updated FDT configuration table @ %p\n",
+                fdt);
 
   /* Convert command line to UCS-2 */
-  loaded_image = grub_efi_get_loaded_image (image_handle);
+  loaded_image = grub_efi_get_loaded_image (grub_efi_image_handle);
   if (loaded_image == NULL)
     {
       grub_error (GRUB_ERR_BAD_FIRMWARE, "missing loaded_image proto");
-      goto unload;
+      goto failure;
     }
   loaded_image->load_options_size = len =
-    (grub_strlen (args) + 1) * sizeof (grub_efi_char16_t);
+    (grub_strlen (linux_args) + 1) * sizeof (grub_efi_char16_t);
   loaded_image->load_options =
     grub_efi_allocate_any_pages (GRUB_EFI_BYTES_TO_PAGES (loaded_image->load_options_size));
   if (!loaded_image->load_options)
-    return grub_errno;
+    return grub_error(GRUB_ERR_BAD_OS, "failed to create kernel parameters");
 
   loaded_image->load_options_size =
     2 * grub_utf8_to_utf16 (loaded_image->load_options, len,
-			    (grub_uint8_t *) args, len, NULL);
+                           (grub_uint8_t *) linux_args, len, NULL);
 
-  grub_dprintf ("linux", "starting image %p\n", image_handle);
-  status = b->start_image (image_handle, 0, NULL);
+  return GRUB_ERR_NONE;
 
-  /* When successful, not reached */
-  grub_error (GRUB_ERR_BAD_OS, "start_image() returned 0x%" PRIxGRUB_EFI_UINTN_T, status);
-  grub_efi_free_pages ((grub_addr_t) loaded_image->load_options,
-		       GRUB_EFI_BYTES_TO_PAGES (loaded_image->load_options_size));
-unload:
-  b->unload_image (image_handle);
+failure:
+  grub_fdt_unload();
+  return grub_error(GRUB_ERR_BAD_OS, "failed to install/update FDT");
+}
+#endif
+
+static void
+free_params (void)
+{
+  grub_efi_loaded_image_t *loaded_image = NULL;
 
-  return grub_errno;
+  loaded_image = grub_efi_get_loaded_image (grub_efi_image_handle);
+  if (loaded_image)
+    {
+      if (loaded_image->load_options)
+       grub_efi_free_pages ((grub_efi_physical_address_t)(grub_efi_uintn_t)loaded_image->load_options,
+                            GRUB_EFI_BYTES_TO_PAGES (loaded_image->load_options_size));
+      loaded_image->load_options = NULL;
+      loaded_image->load_options_size = 0;
+    }
 }
 
+grub_err_t
+grub_arch_efi_linux_boot_image (grub_addr_t addr, char *args)
+{
+  grub_err_t retval;
+
+  grub_dprintf ("linux", "linux command line: '%s'\n", args);
+
+  retval = grub_efi_linux_boot ((char *)addr, handover_offset, (void *)addr);
+
+  /* Never reached... */
+  free_params();
+  return retval;
+ }
+
 static grub_err_t
 grub_linux_boot (void)
 {
@@ -294,8 +283,7 @@ grub_linux_boot (void)
     return grub_errno;
 #endif
 
-  return grub_arch_efi_linux_boot_image ((grub_addr_t) kernel_addr,
-					 kernel_size, linux_args);
+  return grub_arch_efi_linux_boot_image ((grub_addr_t) kernel_addr, linux_args);
 }
 
 static grub_err_t
@@ -572,6 +560,12 @@ fallback:
 
   grub_dprintf ("linux", "kernel @ %p\n", kernel_addr);
 
+#if !defined(__i386__) && !defined(__x86_64__)
+  struct grub_armxx_linux_pe_header *pe;
+  pe = (void *)((unsigned long)kernel_addr + lh.hdr_offset);
+  handover_offset = pe->opt.entry_addr;
+#endif
+
   cmdline_size = grub_loader_cmdline_size (argc, argv) + sizeof (LINUX_IMAGE);
   linux_args = grub_malloc (cmdline_size);
   if (!linux_args)
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 83ddbe26e57..bff833468ee 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -20,6 +20,7 @@
 #ifndef GRUB_EFI_EFI_HEADER
 #define GRUB_EFI_EFI_HEADER	1
 
+#include <grub/efi/pe32.h>
 #include <grub/types.h>
 #include <grub/dl.h>
 #include <grub/efi/api.h>
@@ -36,7 +37,29 @@ struct linux_arch_kernel_header {
   struct grub_pe_image_header pe_image_header;
 };
 
-#define GRUB_EFI_GRUB_VARIABLE_GUID \
+struct grub_arm_linux_pe_header
+{
+  grub_uint32_t magic;
+  struct grub_pe32_coff_header coff;
+  struct grub_pe32_optional_header opt;
+};
+
+struct grub_arm64_linux_pe_header
+{
+  grub_uint32_t magic;
+  struct grub_pe32_coff_header coff;
+  struct grub_pe64_optional_header opt;
+};
+
+#if defined(__arm__)
+# define grub_armxx_linux_pe_header grub_arm_linux_pe_header
+#endif
+
+#if defined(__aarch64__)
+# define grub_armxx_linux_pe_header grub_arm64_linux_pe_header
+#endif
+
+#define GRUB_EFI_GRUB_VARIABLE_GUID             \
   { 0x91376aff, 0xcba6, 0x42be, \
     { 0x94, 0x9d, 0x06, 0xfd, 0xe8, 0x11, 0x28, 0xe8 } \
   }
@@ -173,8 +196,7 @@ grub_err_t EXPORT_FUNC(grub_efi_get_ram_base)(grub_addr_t *);
 #include <grub/file.h>
 grub_err_t grub_arch_efi_linux_load_image_header(grub_file_t file,
                                                 struct linux_arch_kernel_header *lh);
-grub_err_t grub_arch_efi_linux_boot_image(grub_addr_t addr, grub_size_t size,
-                                           char *args);
+grub_err_t grub_arch_efi_linux_boot_image(grub_addr_t addr, char *args);
 
 grub_addr_t grub_efi_section_addr (const char *section);