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Diffstat (limited to 'hw/i386/pc_sysfw_ovmf.c')
-rw-r--r--hw/i386/pc_sysfw_ovmf.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/hw/i386/pc_sysfw_ovmf.c b/hw/i386/pc_sysfw_ovmf.c
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index 0000000000..f4dd92c588
--- /dev/null
+++ b/hw/i386/pc_sysfw_ovmf.c
@@ -0,0 +1,151 @@
+/*
+ * QEMU PC System Firmware (OVMF specific)
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2011-2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/i386/pc.h"
+#include "cpu.h"
+
+#define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
+
+static bool ovmf_flash_parsed;
+static uint8_t *ovmf_table;
+static int ovmf_table_len;
+
+void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
+{
+    uint8_t *ptr;
+    QemuUUID guid;
+    int tot_len;
+
+    /* should only be called once */
+    if (ovmf_flash_parsed) {
+        return;
+    }
+
+    ovmf_flash_parsed = true;
+
+    if (flash_size < TARGET_PAGE_SIZE) {
+        return;
+    }
+
+    /*
+     * if this is OVMF there will be a table footer
+     * guid 48 bytes before the end of the flash file.  If it's
+     * not found, silently abort the flash parsing.
+     */
+    qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
+    guid = qemu_uuid_bswap(guid); /* guids are LE */
+    ptr = flash_ptr + flash_size - 48;
+    if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
+        return;
+    }
+
+    /* if found, just before is two byte table length */
+    ptr -= sizeof(uint16_t);
+    tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
+
+    if (tot_len <= 0) {
+        return;
+    }
+
+    ovmf_table = g_malloc(tot_len);
+    ovmf_table_len = tot_len;
+
+    /*
+     * ptr is the foot of the table, so copy it all to the newly
+     * allocated ovmf_table and then set the ovmf_table pointer
+     * to the table foot
+     */
+    memcpy(ovmf_table, ptr - tot_len, tot_len);
+    ovmf_table += tot_len;
+}
+
+/**
+ * pc_system_ovmf_table_find - Find the data associated with an entry in OVMF's
+ * reset vector GUIDed table.
+ *
+ * @entry: GUID string of the entry to lookup
+ * @data: Filled with a pointer to the entry's value (if not NULL)
+ * @data_len: Filled with the length of the entry's value (if not NULL). Pass
+ *            NULL here if the length of data is known.
+ *
+ * Return: true if the entry was found in the OVMF table; false otherwise.
+ */
+bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
+                               int *data_len)
+{
+    uint8_t *ptr = ovmf_table;
+    int tot_len = ovmf_table_len;
+    QemuUUID entry_guid;
+
+    assert(ovmf_flash_parsed);
+
+    if (qemu_uuid_parse(entry, &entry_guid) < 0) {
+        return false;
+    }
+
+    if (!ptr) {
+        return false;
+    }
+
+    entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
+    while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
+        int len;
+        QemuUUID *guid;
+
+        /*
+         * The data structure is
+         *   arbitrary length data
+         *   2 byte length of entire entry
+         *   16 byte guid
+         */
+        guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
+        len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
+                                        sizeof(uint16_t)));
+
+        /*
+         * just in case the table is corrupt, wouldn't want to spin in
+         * the zero case
+         */
+        if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
+            return false;
+        } else if (len > tot_len) {
+            return false;
+        }
+
+        ptr -= len;
+        tot_len -= len;
+        if (qemu_uuid_is_equal(guid, &entry_guid)) {
+            if (data) {
+                *data = ptr;
+            }
+            if (data_len) {
+                *data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
+            }
+            return true;
+        }
+    }
+    return false;
+}