3 files changed, 41 insertions, 0 deletions
diff --git a/lib/acpi/Makefile b/lib/acpi/Makefile
index caae6c01bd..85a1f774ad 100644
--- a/lib/acpi/Makefile
+++ b/lib/acpi/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
 
+obj-y += acpigen.o
 obj-y += acpi_device.o
 obj-y += acpi_table.o
diff --git a/lib/acpi/acpi_table.c b/lib/acpi/acpi_table.c
index 431776666e..acc55e7fad 100644
--- a/lib/acpi/acpi_table.c
+++ b/lib/acpi/acpi_table.c
@@ -237,6 +237,7 @@ static void acpi_write_xsdt(struct acpi_xsdt *xsdt)
 
 void acpi_setup_base_tables(struct acpi_ctx *ctx, void *start)
 {
+	ctx->base = start;
 	ctx->current = start;
 
 	/* Align ACPI tables to 16 byte */
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
new file mode 100644
index 0000000000..a42ae26494
--- /dev/null
+++ b/lib/acpi/acpigen.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generation of ACPI (Advanced Configuration and Power Interface) tables
+ *
+ * Copyright 2019 Google LLC
+ * Mostly taken from coreboot
+ */
+
+#define LOG_CATEGORY LOGC_ACPI
+
+#include <common.h>
+#include <dm.h>
+#include <acpi/acpigen.h>
+#include <dm/acpi.h>
+
+u8 *acpigen_get_current(struct acpi_ctx *ctx)
+{
+	return ctx->current;
+}
+
+void acpigen_emit_byte(struct acpi_ctx *ctx, uint data)
+{
+	*(u8 *)ctx->current++ = data;
+}
+
+void acpigen_emit_word(struct acpi_ctx *ctx, uint data)
+{
+	acpigen_emit_byte(ctx, data & 0xff);
+	acpigen_emit_byte(ctx, (data >> 8) & 0xff);
+}
+
+void acpigen_emit_dword(struct acpi_ctx *ctx, uint data)
+{
+	/* Output the value in little-endian format */
+	acpigen_emit_byte(ctx, data & 0xff);
+	acpigen_emit_byte(ctx, (data >> 8) & 0xff);
+	acpigen_emit_byte(ctx, (data >> 16) & 0xff);
+	acpigen_emit_byte(ctx, (data >> 24) & 0xff);
+}