[Qemu-arm] [PATCH v2 6/8] hw: arm: Support both legacy and current RSDP build

[Samuel Ortiz <sameo@linux.intel.com>]

We add the ability to build legacy or current RSDP tables, based on the
AcpiRsdpData revision field passed to build_rsdp().
Although arm/virt only uses RSDP v2, adding that capability to
build_rsdp will allow us to share the RSDP build code between ARM and x86.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
---
 hw/arm/virt-acpi-build.c | 37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 4782aea4fe..e1338b6f5a 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -378,23 +378,38 @@ build_rsdp(GArray *tbl, BIOSLinker *linker, AcpiRsdpData *rsdp_data)
     g_array_append_vals(tbl, rsdp_data->oem_id, 6); /* OEMID */
     build_append_int_noprefix(tbl, rsdp_data->revision, 1); /* Revision */
     build_append_int_noprefix(tbl, 0, 4); /* RsdtAddress */
-    build_append_int_noprefix(tbl, 36, 4); /* Length */
-
-    /* XSDT address to be filled by guest linker */
-    build_append_int_noprefix(tbl, 0, 8); /* XsdtAddress */
-    bios_linker_loader_add_pointer(linker, ACPI_BUILD_RSDP_FILE,
-                                   24, 8,
-                                   ACPI_BUILD_TABLE_FILE,
-                                   *rsdp_data->xsdt_tbl_offset);
-
-    build_append_int_noprefix(tbl, 0, 1); /* Extended Checksum */
-    build_append_int_noprefix(tbl, 0, 3); /* Reserved */
+    if (rsdp_data->rsdt_tbl_offset) {
+        /* RSDT address to be filled by guest linker */
+        bios_linker_loader_add_pointer(linker,
+                                       ACPI_BUILD_RSDP_FILE, 16, 4,
+                                       ACPI_BUILD_TABLE_FILE,
+                                       *rsdp_data->rsdt_tbl_offset);
+    }
 
     /* Checksum to be filled by guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
                                     0, 20, /* ACPI rev 1.0 RSDP size */
                                     8);
 
+    if (rsdp_data->revision == 0) {
+        /* ACPI 1.0 RSDP, we're done */
+        return;
+    }
+
+    /* The RSDP revision is 2 and later, we must have an XSDT pointer */
+    g_assert(rsdp_data->xsdt_tbl_offset != NULL);
+
+    build_append_int_noprefix(tbl, 36, 4); /* Length */
+
+    /* XSDT address to be filled by guest linker */
+    build_append_int_noprefix(tbl, 0, 8); /* XsdtAddress */
+    bios_linker_loader_add_pointer(linker, ACPI_BUILD_RSDP_FILE, 24, 8,
+                                   ACPI_BUILD_TABLE_FILE,
+                                   *rsdp_data->xsdt_tbl_offset);
+
+    build_append_int_noprefix(tbl, 0, 1); /* Extended Checksum */
+    build_append_int_noprefix(tbl, 0, 3); /* Reserved */
+
     /* Extended checksum to be filled by Guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
                                     0, 36, /* ACPI rev 2.0 RSDP size */
-- 
2.19.2