efi_loader: implement EFI_DT_FIXUP_PROTOCOL

A boot manager like GRUB can use the protocol to

* apply U-Boot's fix-ups to the a device-tree
* let U-Boot make memory reservations according to the device-tree
* install the device-tree as a configuration table

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

cmd/bootefi.c

@@ -211,86 +211,6 @@ done:
 	return ret;
 }
 
-/**
- * efi_reserve_memory() - add reserved memory to memory map
- *
- * @addr:	start address of the reserved memory range
- * @size:	size of the reserved memory range
- * @nomap:	indicates that the memory range shall not be accessed by the
- *		UEFI payload
- */
-static void efi_reserve_memory(u64 addr, u64 size, bool nomap)
-{
-	int type;
-	efi_uintn_t ret;
-
-	/* Convert from sandbox address space. */
-	addr = (uintptr_t)map_sysmem(addr, 0);
-
-	if (nomap)
-		type = EFI_RESERVED_MEMORY_TYPE;
-	else
-		type = EFI_BOOT_SERVICES_DATA;
-
-	ret = efi_add_memory_map(addr, size, type);
-	if (ret != EFI_SUCCESS)
-		log_err("Reserved memory mapping failed addr %llx size %llx\n",
-			addr, size);
-}
-
-/**
- * efi_carve_out_dt_rsv() - Carve out DT reserved memory ranges
- *
- * The mem_rsv entries of the FDT are added to the memory map. Any failures are
- * ignored because this is not critical and we would rather continue to try to
- * boot.
- *
- * @fdt: Pointer to device tree
- */
-static void efi_carve_out_dt_rsv(void *fdt)
-{
-	int nr_rsv, i;
-	u64 addr, size;
-	int nodeoffset, subnode;
-
-	nr_rsv = fdt_num_mem_rsv(fdt);
-
-	/* Look for an existing entry and add it to the efi mem map. */
-	for (i = 0; i < nr_rsv; i++) {
-		if (fdt_get_mem_rsv(fdt, i, &addr, &size) != 0)
-			continue;
-		efi_reserve_memory(addr, size, false);
-	}
-
-	/* process reserved-memory */
-	nodeoffset = fdt_subnode_offset(fdt, 0, "reserved-memory");
-	if (nodeoffset >= 0) {
-		subnode = fdt_first_subnode(fdt, nodeoffset);
-		while (subnode >= 0) {
-			fdt_addr_t fdt_addr;
-			fdt_size_t fdt_size;
-
-			/* check if this subnode has a reg property */
-			fdt_addr = fdtdec_get_addr_size_auto_parent(
-						fdt, nodeoffset, subnode,
-						"reg", 0, &fdt_size, false);
-			/*
-			 * The /reserved-memory node may have children with
-			 * a size instead of a reg property.
-			 */
-			if (fdt_addr != FDT_ADDR_T_NONE &&
-			    fdtdec_get_is_enabled(fdt, subnode)) {
-				bool nomap;
-
-				nomap = !!fdt_getprop(fdt, subnode, "no-map",
-						      NULL);
-				efi_reserve_memory(fdt_addr, fdt_size, nomap);
-			}
-			subnode = fdt_next_subnode(fdt, subnode);
-		}
-	}
-}
-
 /**
  * get_config_table() - get configuration table
  *

cmd/efidebug.c

@@ -8,6 +8,7 @@
 #include <charset.h>
 #include <common.h>
 #include <command.h>
+#include <efi_dt_fixup.h>
 #include <efi_loader.h>
 #include <efi_rng.h>
 #include <exports.h>
@@ -495,6 +496,10 @@ static const struct {
 		"PXE Base Code",
 		EFI_PXE_BASE_CODE_PROTOCOL_GUID,
 	},
+	{
+		"Device-Tree Fixup",
+		EFI_DT_FIXUP_PROTOCOL_GUID,
+	},
 	/* Configuration table GUIDs */
 	{
 		"ACPI table",

include/efi_dt_fixup.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * EFI_DT_FIXUP_PROTOCOL
+ *
+ * Copyright (c) 2020 Heinrich Schuchardt
+ */
+
+#include <efi_api.h>
+
+#define EFI_DT_FIXUP_PROTOCOL_GUID \
+	EFI_GUID(0xe617d64c, 0xfe08, 0x46da, 0xf4, 0xdc, \
+		 0xbb, 0xd5, 0x87, 0x0c, 0x73, 0x00)
+
+#define EFI_DT_FIXUP_PROTOCOL_REVISION 0x00010000
+
+/* Add nodes and update properties */
+#define EFI_DT_APPLY_FIXUPS    0x00000001
+/*
+ * Reserve memory according to the /reserved-memory node
+ * and the memory reservation block
+ */
+#define EFI_DT_RESERVE_MEMORY  0x00000002
+/* Install the device-tree as configuration table */
+#define EFI_DT_INSTALL_TABLE   0x00000004
+
+#define EFI_DT_ALL (EFI_DT_APPLY_FIXUPS | \
+		    EFI_DT_RESERVE_MEMORY | \
+		    EFI_DT_INSTALL_TABLE)
+
+struct efi_dt_fixup_protocol {
+	u64 revision;
+	efi_status_t (EFIAPI *fixup) (struct efi_dt_fixup_protocol *this,
+				      void *dtb,
+				      efi_uintn_t *buffer_size,
+				      u32 flags);
+};
+
+extern struct efi_dt_fixup_protocol efi_dt_fixup_prot;
+extern const efi_guid_t efi_guid_dt_fixup_protocol;

include/efi_loader.h

@@ -411,6 +411,8 @@ void efi_runtime_detach(void);
 /* efi_convert_pointer() - convert pointer to virtual address */
 efi_status_t EFIAPI efi_convert_pointer(efi_uintn_t debug_disposition,
 					void **address);
+/* Carve out DT reserved memory ranges */
+void efi_carve_out_dt_rsv(void *fdt);
 /* Called by bootefi to make console interface available */
 efi_status_t efi_console_register(void);
 /* Called by bootefi to make all disk storage accessible as EFI objects */

lib/efi_loader/Makefile

@@ -29,6 +29,9 @@ obj-y += efi_console.o
 obj-y += efi_device_path.o
 obj-$(CONFIG_EFI_DEVICE_PATH_TO_TEXT) += efi_device_path_to_text.o
 obj-y += efi_device_path_utilities.o
+ifeq ($(CONFIG_GENERATE_ACPI_TABLE),)
+obj-y += efi_dt_fixup.o
+endif
 obj-y += efi_file.o
 obj-$(CONFIG_EFI_LOADER_HII) += efi_hii.o
 obj-y += efi_image_loader.o

lib/efi_loader/efi_dt_fixup.c

@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * EFI_DT_FIXUP_PROTOCOL
+ *
+ * Copyright (c) 2020 Heinrich Schuchardt
+ */
+
+#include <common.h>
+#include <efi_dt_fixup.h>
+#include <efi_loader.h>
+#include <mapmem.h>
+
+static efi_status_t EFIAPI efi_dt_fixup(struct efi_dt_fixup_protocol *this,
+					void *dtb,
+					efi_uintn_t *buffer_size,
+					u32 flags);
+
+struct efi_dt_fixup_protocol efi_dt_fixup_prot = {
+	.revision = EFI_DT_FIXUP_PROTOCOL_REVISION,
+	.fixup = efi_dt_fixup
+};
+
+const efi_guid_t efi_guid_dt_fixup_protocol = EFI_DT_FIXUP_PROTOCOL_GUID;
+
+/**
+ * efi_reserve_memory() - add reserved memory to memory map
+ *
+ * @addr:	start address of the reserved memory range
+ * @size:	size of the reserved memory range
+ * @nomap:	indicates that the memory range shall not be accessed by the
+ *		UEFI payload
+ */
+static void efi_reserve_memory(u64 addr, u64 size, bool nomap)
+{
+	int type;
+	efi_uintn_t ret;
+
+	/* Convert from sandbox address space. */
+	addr = (uintptr_t)map_sysmem(addr, 0);
+
+	if (nomap)
+		type = EFI_RESERVED_MEMORY_TYPE;
+	else
+		type = EFI_BOOT_SERVICES_DATA;
+
+	ret = efi_add_memory_map(addr, size, type);
+	if (ret != EFI_SUCCESS)
+		log_err("Reserved memory mapping failed addr %llx size %llx\n",
+			addr, size);
+}
+
+/**
+ * efi_carve_out_dt_rsv() - Carve out DT reserved memory ranges
+ *
+ * The mem_rsv entries of the FDT are added to the memory map. Any failures are
+ * ignored because this is not critical and we would rather continue to try to
+ * boot.
+ *
+ * @fdt: Pointer to device tree
+ */
+void efi_carve_out_dt_rsv(void *fdt)
+{
+	int nr_rsv, i;
+	u64 addr, size;
+	int nodeoffset, subnode;
+
+	nr_rsv = fdt_num_mem_rsv(fdt);
+
+	/* Look for an existing entry and add it to the efi mem map. */
+	for (i = 0; i < nr_rsv; i++) {
+		if (fdt_get_mem_rsv(fdt, i, &addr, &size) != 0)
+			continue;
+		efi_reserve_memory(addr, size, false);
+	}
+
+	/* process reserved-memory */
+	nodeoffset = fdt_subnode_offset(fdt, 0, "reserved-memory");
+	if (nodeoffset >= 0) {
+		subnode = fdt_first_subnode(fdt, nodeoffset);
+		while (subnode >= 0) {
+			fdt_addr_t fdt_addr;
+			fdt_size_t fdt_size;
+
+			/* check if this subnode has a reg property */
+			fdt_addr = fdtdec_get_addr_size_auto_parent(
+						fdt, nodeoffset, subnode,
+						"reg", 0, &fdt_size, false);
+			/*
+			 * The /reserved-memory node may have children with
+			 * a size instead of a reg property.
+			 */
+			if (fdt_addr != FDT_ADDR_T_NONE &&
+			    fdtdec_get_is_enabled(fdt, subnode)) {
+				bool nomap;
+
+				nomap = !!fdt_getprop(fdt, subnode, "no-map",
+						      NULL);
+				efi_reserve_memory(fdt_addr, fdt_size, nomap);
+			}
+			subnode = fdt_next_subnode(fdt, subnode);
+		}
+	}
+}
+
+static efi_status_t EFIAPI efi_dt_fixup(struct efi_dt_fixup_protocol *this,
+					void *dtb,
+					efi_uintn_t *buffer_size,
+					u32 flags)
+{
+	efi_status_t ret;
+	size_t required_size;
+	bootm_headers_t img = { 0 };
+
+	EFI_ENTRY("%p, %p, %p, %d", this, dtb, buffer_size, flags);
+
+	if (this != &efi_dt_fixup_prot || !dtb || !buffer_size ||
+	    !flags || (flags & ~EFI_DT_ALL)) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+	if (fdt_check_header(dtb)) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+	if (flags & EFI_DT_APPLY_FIXUPS) {
+		required_size = fdt_off_dt_strings(dtb) +
+				fdt_size_dt_strings(dtb) +
+				0x3000;
+	} else {
+		required_size = fdt_totalsize(dtb);
+	}
+	if (required_size > *buffer_size) {
+		*buffer_size = required_size;
+		ret = EFI_BUFFER_TOO_SMALL;
+		goto out;
+	}
+	fdt_set_totalsize(dtb, *buffer_size);
+
+	if (flags & EFI_DT_APPLY_FIXUPS) {
+		if (image_setup_libfdt(&img, dtb, 0, NULL)) {
+			log_err("failed to process device tree\n");
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+	}
+	if (flags & EFI_DT_RESERVE_MEMORY)
+		efi_carve_out_dt_rsv(dtb);
+
+	if (EFI_DT_INSTALL_TABLE) {
+		ret = efi_install_configuration_table(&efi_guid_fdt, dtb);
+		if (ret != EFI_SUCCESS) {
+			log_err("ERROR: failed to install device tree\n");
+			goto out;
+		}
+	}
+
+	ret = EFI_SUCCESS;
+out:
+	return EFI_EXIT(ret);
+}

lib/efi_loader/efi_root_node.c

@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <malloc.h>
+#include <efi_dt_fixup.h>
 #include <efi_loader.h>
 
 const efi_guid_t efi_u_boot_guid = U_BOOT_GUID;
@@ -60,6 +61,11 @@ efi_status_t efi_root_node_register(void)
 			 /* Device path utilities protocol */
 			 &efi_guid_device_path_utilities_protocol,
 			 (void *)&efi_device_path_utilities,
+#if !CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
+			 /* Device-tree fix-up protocol */
+			 &efi_guid_dt_fixup_protocol,
+			 (void *)&efi_dt_fixup_prot,
+#endif
 #if CONFIG_IS_ENABLED(EFI_UNICODE_COLLATION_PROTOCOL2)
 #if CONFIG_IS_ENABLED(EFI_UNICODE_COLLATION_PROTOCOL)
 			 /* Deprecated Unicode collation protocol */