1 files changed, 49 insertions, 0 deletions
diff --git a/lib/acpi/csrt.c b/lib/acpi/csrt.c
new file mode 100644
index 00000000000..00927e53406
--- /dev/null
+++ b/lib/acpi/csrt.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Write an ACPI Core System Resource Table (CSRT)
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#define LOG_CATEGORY LOGC_ACPI
+
+#include <mapmem.h>
+#include <tables_csum.h>
+#include <acpi/acpi_table.h>
+#include <dm/acpi.h>
+#include <linux/string.h>
+
+__weak int acpi_fill_csrt(struct acpi_ctx *ctx)
+{
+	return 0;
+}
+
+int acpi_write_csrt(struct acpi_ctx *ctx, const struct acpi_writer *entry)
+{
+	struct acpi_table_header *header;
+	struct acpi_csrt *csrt;
+	int ret;
+
+	csrt = ctx->current;
+	header = &csrt->header;
+
+	memset(csrt, '\0', sizeof(struct acpi_csrt));
+
+	/* Fill out header fields */
+	acpi_fill_header(header, "CSRT");
+	header->revision = 0;
+	acpi_inc(ctx, sizeof(*header));
+
+	ret = acpi_fill_csrt(ctx);
+	if (ret)
+		return log_msg_ret("fill", ret);
+
+	/* (Re)calculate length and checksum */
+	header->length = (ulong)ctx->current - (ulong)csrt;
+	header->checksum = table_compute_checksum(csrt, header->length);
+
+	acpi_add_table(ctx, csrt);
+
+	return 0;
+}
+ACPI_WRITER(5csrt, "CSRT", acpi_write_csrt, 0);