efi_loader: define UpdateCapsule api

In this commit, skeleton functions for capsule-related API's are
added under CONFIG_EFI_UPDATE_CAPSULE configuration.
Detailed implementation for a specific capsule type will be added
in the succeeding patches.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

lib/efi_loader/efi_capsule.c

@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  EFI Capsule
+ *
+ *  Copyright (c) 2018 Linaro Limited
+ *			Author: AKASHI Takahiro
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+#include <efi_variable.h>
+#include <fs.h>
+#include <malloc.h>
+#include <sort.h>
+
+const efi_guid_t efi_guid_capsule_report = EFI_CAPSULE_REPORT_GUID;
+
+/**
+ * get_last_capsule - get the last capsule index
+ *
+ * Retrieve the index of the capsule invoked last time from "CapsuleLast"
+ * variable.
+ *
+ * Return:
+ * * > 0	- the last capsule index invoked
+ * * 0xffff	- on error, or no capsule invoked yet
+ */
+static __maybe_unused unsigned int get_last_capsule(void)
+{
+	u16 value16[11]; /* "CapsuleXXXX": non-null-terminated */
+	char value[11], *p;
+	efi_uintn_t size;
+	unsigned long index = 0xffff;
+	efi_status_t ret;
+
+	size = sizeof(value16);
+	ret = efi_get_variable_int(L"CapsuleLast", &efi_guid_capsule_report,
+				   NULL, &size, value16, NULL);
+	if (ret != EFI_SUCCESS || u16_strncmp(value16, L"Capsule", 7))
+		goto err;
+
+	p = value;
+	utf16_utf8_strcpy(&p, value16);
+	strict_strtoul(&value[7], 16, &index);
+err:
+	return index;
+}
+
+/**
+ * set_capsule_result - set a result variable
+ * @capsule:		Capsule
+ * @return_status:	Return status
+ *
+ * Create and set a result variable, "CapsuleXXXX", for the capsule,
+ * @capsule.
+ */
+static __maybe_unused
+void set_capsule_result(int index, struct efi_capsule_header *capsule,
+			efi_status_t return_status)
+{
+	u16 variable_name16[12];
+	struct efi_capsule_result_variable_header result;
+	struct efi_time time;
+	efi_status_t ret;
+
+	efi_create_indexed_name(variable_name16, "Capsule", index);
+
+	result.variable_total_size = sizeof(result);
+	result.capsule_guid = capsule->capsule_guid;
+	ret = EFI_CALL((*efi_runtime_services.get_time)(&time, NULL));
+	if (ret == EFI_SUCCESS)
+		memcpy(&result.capsule_processed, &time, sizeof(time));
+	else
+		memset(&result.capsule_processed, 0, sizeof(time));
+	result.capsule_status = return_status;
+	ret = efi_set_variable(variable_name16, &efi_guid_capsule_report,
+			       EFI_VARIABLE_NON_VOLATILE |
+			       EFI_VARIABLE_BOOTSERVICE_ACCESS |
+			       EFI_VARIABLE_RUNTIME_ACCESS,
+			       sizeof(result), &result);
+	if (ret)
+		printf("EFI: creating %ls failed\n", variable_name16);
+}
+
+/**
+ * efi_update_capsule() - process information from operating system
+ * @capsule_header_array:	Array of virtual address pointers
+ * @capsule_count:		Number of pointers in capsule_header_array
+ * @scatter_gather_list:	Array of physical address pointers
+ *
+ * This function implements the UpdateCapsule() runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return:			status code
+ */
+efi_status_t EFIAPI efi_update_capsule(
+		struct efi_capsule_header **capsule_header_array,
+		efi_uintn_t capsule_count,
+		u64 scatter_gather_list)
+{
+	struct efi_capsule_header *capsule;
+	unsigned int i;
+	efi_status_t ret;
+
+	EFI_ENTRY("%p, %lu, %llu\n", capsule_header_array, capsule_count,
+		  scatter_gather_list);
+
+	if (!capsule_count) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	ret = EFI_UNSUPPORTED;
+	for (i = 0, capsule = *capsule_header_array; i < capsule_count;
+	     i++, capsule = *(++capsule_header_array)) {
+	}
+out:
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_query_capsule_caps() - check if capsule is supported
+ * @capsule_header_array:	Array of virtual pointers
+ * @capsule_count:		Number of pointers in capsule_header_array
+ * @maximum_capsule_size:	Maximum capsule size
+ * @reset_type:			Type of reset needed for capsule update
+ *
+ * This function implements the QueryCapsuleCapabilities() runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return:			status code
+ */
+efi_status_t EFIAPI efi_query_capsule_caps(
+		struct efi_capsule_header **capsule_header_array,
+		efi_uintn_t capsule_count,
+		u64 *maximum_capsule_size,
+		u32 *reset_type)
+{
+	struct efi_capsule_header *capsule __attribute__((unused));
+	unsigned int i;
+	efi_status_t ret;
+
+	EFI_ENTRY("%p, %lu, %p, %p\n", capsule_header_array, capsule_count,
+		  maximum_capsule_size, reset_type);
+
+	if (!maximum_capsule_size) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	*maximum_capsule_size = U64_MAX;
+	*reset_type = EFI_RESET_COLD;
+
+	ret = EFI_SUCCESS;
+	for (i = 0, capsule = *capsule_header_array; i < capsule_count;
+	     i++, capsule = *(++capsule_header_array)) {
+		/* TODO */
+	}
+out:
+	return EFI_EXIT(ret);
+}