[PATCH gnumach 2/5] acpi_parse_apic.c: find the ACPI RSDP from any multiboot2 data available.

[Mike Kelly]

---
 i386/i386/multiboot2_hdr_asm.h |  4 ++-
 i386/i386at/acpi_parse_apic.c  | 65 ++++++++++++++++++++++++++++++++--
 2 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/i386/i386/multiboot2_hdr_asm.h b/i386/i386/multiboot2_hdr_asm.h
index f4ce4697..37ed8837 100644
--- a/i386/i386/multiboot2_hdr_asm.h
+++ b/i386/i386/multiboot2_hdr_asm.h
@@ -29,12 +29,14 @@ multiboot2_hdr:
          aligned with padding if required. */
        .short MULTIBOOT2_HEADER_TAG_INFORMATION_REQUEST
        .short 0
-       .long 32
+       .long 40
        .long MULTIBOOT2_TAG_TYPE_MMAP
        .long MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO
        .long MULTIBOOT2_TAG_TYPE_CMDLINE
        .long MULTIBOOT2_TAG_TYPE_MODULE
        .long MULTIBOOT2_TAG_TYPE_ELF_SECTIONS
+       .long MULTIBOOT2_TAG_TYPE_ACPI_OLD
+       .long MULTIBOOT2_TAG_TYPE_ACPI_NEW
        .long  0 /* alignment */
        /* Align modules on page boundaries */
        .short MULTIBOOT2_HEADER_TAG_MODULE_ALIGN
diff --git a/i386/i386at/acpi_parse_apic.c b/i386/i386at/acpi_parse_apic.c
index 9edb524c..b33b5324 100644
--- a/i386/i386at/acpi_parse_apic.c
+++ b/i386/i386at/acpi_parse_apic.c
@@ -24,6 +24,7 @@
 #include <stdint.h> /* uint16_t, uint32_t... */
 
 #include <mach/machine.h>   /* machine_slot */
+#include <mach/machine/multiboot2.h>
 
 #include <kern/printf.h>    /* printf */
 #include <kern/debug.h>
@@ -675,12 +676,72 @@ acpi_apic_init(void)
     return ACPI_SUCCESS;
 }
 
+static const struct acpi_rsdp2 *
+acpi_mb2_initialise (const struct multiboot2_raw_info *bi)
+{
+  const struct acpi_rsdp2 *rsdp = NULL;
+
+  assert (bi != NULL);
+
+  uint32_t tags_len = bi->total_size
+    - offsetof (struct multiboot2_raw_info, content);
+  uint32_t offset = 0;
+
+  while (offset < tags_len)
+    {
+      const struct multiboot2_tag *tag =
+       (const struct multiboot2_tag *)(&bi->content[offset]);
+
+      switch (tag->type)
+       {
+       case MULTIBOOT2_TAG_TYPE_ACPI_OLD:
+         {
+           if (rsdp == NULL)
+             {
+               const struct multiboot2_tag_old_acpi *old_acpi =
+                 (const struct multiboot2_tag_old_acpi *)tag;
+
+               if ((old_acpi->size - offsetof (typeof (*old_acpi), rsdp))
+                   >= sizeof (struct acpi_rsdp))
+                 rsdp = (const struct acpi_rsdp2 *)old_acpi->rsdp;
+             }
+         }
+         break;
+
+       case MULTIBOOT2_TAG_TYPE_ACPI_NEW:
+         {
+           const struct multiboot2_tag_new_acpi *new_acpi =
+             (const struct multiboot2_tag_new_acpi *)tag;
+
+           if ((new_acpi->size - offsetof (typeof (*new_acpi), rsdp))
+               >= sizeof (struct acpi_rsdp2))
+             rsdp = (const struct acpi_rsdp2 *)new_acpi->rsdp;
+         }
+         break;
+
+       default:
+         break;
+       }
+
+      offset += MULTIBOOT2_NEXT_TAG_OFFSET (tag->size);
+    }
+
+  if (rsdp != NULL && acpi_check_rsdp (rsdp) <= 0)
+    rsdp = NULL;
+
+  return rsdp;
+}
+
 void
 acpi_initialise (const struct multiboot2_raw_info *bi)
 {
-  const struct acpi_rsdp2 *rsdp;
+  const struct acpi_rsdp2 *rsdp = NULL;
+
+  if (bi != NULL)
+    rsdp = acpi_mb2_initialise (bi);
 
-  rsdp = acpi_rsdp_from_bios ();
+  if (rsdp == NULL)
+    rsdp = acpi_rsdp_from_bios ();
 
   if (rsdp != NULL)
     {
-- 
2.47.3