[PATCH RFC v2 3/4] hvmloader/ovmf: setup ovmf_info

[Wei Liu <wei.liu2@citrix.com>]

OVMF info contains E820 map allocated by hvmloader. This info is passed
to OVMF to help it do proper initialization.

Currently only E820 is necessary, but we reserve spaces for other tables
in ovmf_info for later usage.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/firmware/hvmloader/ovmf.c |   49 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/tools/firmware/hvmloader/ovmf.c b/tools/firmware/hvmloader/ovmf.c
index 7826095..1564263 100644
--- a/tools/firmware/hvmloader/ovmf.c
+++ b/tools/firmware/hvmloader/ovmf.c
@@ -46,10 +46,55 @@
 #define LOWCHUNK_SIZE           0x00010000
 #define LOWCHUNK_MAXOFFSET      0x0000FFFF
 #define LOWCHUNK_END            (OVMF_BEGIN + OVMF_SIZE)
+#define OVMF_INFO_PHYSICAL_ADDRESS 0X00001000
 
 extern unsigned char dsdt_anycpu[];
 extern int dsdt_anycpu_len;
 
+#define OVMF_INFO_MAX_TABLES 4
+struct ovmf_info {
+    char signature[11]; /* XenHVMOVMF\0 */
+    char pad[3];
+    uint8_t length;     /* Length of this struct */
+    uint8_t checksum;   /* Set such that the sum over bytes 0..length == 0 */
+    /*
+     * Physical address of an array of tables_nr elements.
+     *
+     * Each element is a 32 bit value contianing the physical address
+     * of a BIOS table.
+     */
+    uint32_t tables;
+    uint32_t tables_nr;
+    /*
+     * Physical address of the e820 table, contains e820_nr entries.
+     */
+    uint32_t e820;
+    uint32_t e820_nr;
+} __attribute__ ((packed));
+
+static void ovmf_setup_bios_info(void)
+{
+    struct ovmf_info *info = (void *)OVMF_INFO_PHYSICAL_ADDRESS;
+
+    memset(info, 0, sizeof(*info));
+
+    memcpy(info->signature, "XenHVMOVMF", sizeof(info->signature));
+    info->length = sizeof(*info);
+}
+
+static void ovmf_finish_bios_info(void)
+{
+    struct ovmf_info *info = (void *)OVMF_INFO_PHYSICAL_ADDRESS;
+    uint32_t i;
+    uint8_t checksum;
+
+    checksum = 0;
+    for ( i = 0; i < info->length; i++ )
+        checksum += ((uint8_t *)(info))[i];
+
+    info->checksum = -checksum;
+}
+
 static void ovmf_load(const struct bios_config *config)
 {
     xen_pfn_t mfn;
@@ -104,8 +149,8 @@ struct bios_config ovmf_config =  {
 
     .load_roms = 0,
 
-    .bios_info_setup = NULL,
-    .bios_info_finish = NULL,
+    .bios_info_setup = ovmf_setup_bios_info,
+    .bios_info_finish = ovmf_finish_bios_info,
 
     .e820_setup = NULL,
 
-- 
1.7.10.4