some comment in ACPI table

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1917 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

diff --git a/src/arch/i386/include/arch/acpi.h b/src/arch/i386/include/arch/acpi.h
index d51195527c28526f3f4946008d0963ca653f3250..91cc10c109b1d6ce83f37c7775f4d330fdb47374 100644 (file)
--- a/src/arch/i386/include/arch/acpi.h
+++ b/src/arch/i386/include/arch/acpi.h
@@ -39,14 +39,14 @@ typedef unsigned long long u64;
 /* ACPI 2.0 table RSDP */
 
 typedef struct acpi_rsdp {
-       char  signature[8];
-       u8    checksum;
-       char  oem_id[6];
-       u8    revision;
-       u32   rsdt_address;
-       u32   length;
-       u64   xsdt_address;
-       u8    ext_checksum;
+       char  signature[8];     /* RSDP signature "RSD PTR" */
+       u8    checksum;         /* checksum of the first 20 bytes */
+       char  oem_id[6];        /* OEM ID, "LXBIOS" */
+       u8    revision;         /* 0 for APCI 1.0, 2 for ACPI 2.0 */
+       u32   rsdt_address;     /* physical address of RSDT */
+       u32   length;           /* total length of RSDP (including extended part) */
+       u64   xsdt_address;     /* physical address of XSDT */
+       u8    ext_checksum;     /* chechsum of whole table */
        u8    reserved[3];
 } __attribute__((packed)) acpi_rsdp_t;
 
@@ -77,14 +77,18 @@ typedef struct acpi_table_header         /* ACPI common table header */
 } __attribute__ ((packed)) acpi_header_t;
 
 /* RSDT */
-
 typedef struct acpi_rsdt {
        struct acpi_table_header header;
        u32 entry[8];
 } __attribute__ ((packed)) acpi_rsdt_t;
 
-/* HPET TIMERS */
+/* XSDT */
+typedef struct acpi_xsdt {
+       struct acpi_table_header header;
+       u64 entry[8];
+} __attribute__ ((packed)) acpi_xsdt_t;
 
+/* HPET TIMERS */
 typedef struct acpi_hpet {
        struct acpi_table_header header;
        u32 id;