diff options
Diffstat (limited to 'hw/i386/pc_sysfw_ovmf.c')
-rw-r--r-- | hw/i386/pc_sysfw_ovmf.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/hw/i386/pc_sysfw_ovmf.c b/hw/i386/pc_sysfw_ovmf.c new file mode 100644 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; +} |