1 files changed, 82 insertions, 0 deletions
diff --git a/lib/acpi/acpi_table.c b/lib/acpi/acpi_table.c
index 4e354d313f..59980bc0e1 100644
--- a/lib/acpi/acpi_table.c
+++ b/lib/acpi/acpi_table.c
@@ -181,3 +181,85 @@ int acpi_add_table(struct acpi_ctx *ctx, void *table)
 
 	return 0;
 }
+
+static void acpi_write_rsdp(struct acpi_rsdp *rsdp, struct acpi_rsdt *rsdt,
+			    struct acpi_xsdt *xsdt)
+{
+	memset(rsdp, 0, sizeof(struct acpi_rsdp));
+
+	memcpy(rsdp->signature, RSDP_SIG, 8);
+	memcpy(rsdp->oem_id, OEM_ID, 6);
+
+	rsdp->length = sizeof(struct acpi_rsdp);
+	rsdp->rsdt_address = map_to_sysmem(rsdt);
+
+	rsdp->xsdt_address = map_to_sysmem(xsdt);
+	rsdp->revision = ACPI_RSDP_REV_ACPI_2_0;
+
+	/* Calculate checksums */
+	rsdp->checksum = table_compute_checksum(rsdp, 20);
+	rsdp->ext_checksum = table_compute_checksum(rsdp,
+						    sizeof(struct acpi_rsdp));
+}
+
+static void acpi_write_rsdt(struct acpi_rsdt *rsdt)
+{
+	struct acpi_table_header *header = &rsdt->header;
+
+	/* Fill out header fields */
+	acpi_fill_header(header, "RSDT");
+	header->length = sizeof(struct acpi_rsdt);
+	header->revision = 1;
+
+	/* Entries are filled in later, we come with an empty set */
+
+	/* Fix checksum */
+	header->checksum = table_compute_checksum(rsdt,
+						  sizeof(struct acpi_rsdt));
+}
+
+static void acpi_write_xsdt(struct acpi_xsdt *xsdt)
+{
+	struct acpi_table_header *header = &xsdt->header;
+
+	/* Fill out header fields */
+	acpi_fill_header(header, "XSDT");
+	header->length = sizeof(struct acpi_xsdt);
+	header->revision = 1;
+
+	/* Entries are filled in later, we come with an empty set */
+
+	/* Fix checksum */
+	header->checksum = table_compute_checksum(xsdt,
+						  sizeof(struct acpi_xsdt));
+}
+
+void acpi_setup_base_tables(struct acpi_ctx *ctx, void *start)
+{
+	struct acpi_xsdt *xsdt;
+
+	ctx->current = start;
+
+	/* Align ACPI tables to 16 byte */
+	acpi_align(ctx);
+
+	/* We need at least an RSDP and an RSDT Table */
+	ctx->rsdp = ctx->current;
+	acpi_inc_align(ctx, sizeof(struct acpi_rsdp));
+	ctx->rsdt = ctx->current;
+	acpi_inc_align(ctx, sizeof(struct acpi_rsdt));
+	xsdt = ctx->current;
+	acpi_inc_align(ctx, sizeof(struct acpi_xsdt));
+
+	/* clear all table memory */
+	memset((void *)start, '\0', ctx->current - start);
+
+	acpi_write_rsdp(ctx->rsdp, ctx->rsdt, xsdt);
+	acpi_write_rsdt(ctx->rsdt);
+	acpi_write_xsdt(xsdt);
+	/*
+	 * Per ACPI spec, the FACS table address must be aligned to a 64 byte
+	 * boundary (Windows checks this, but Linux does not).
+	 */
+	acpi_align64(ctx);
+}