qemu/hw/acpi/bios-linker-loader.c

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/* Dynamic linker/loader of ACPI tables
*
* Copyright (C) 2013 Red Hat Inc
*
* Author: Michael S. Tsirkin <mst@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu-common.h"
#include "hw/acpi/bios-linker-loader.h"
#include "hw/nvram/fw_cfg.h"
#include "qemu/bswap.h"
#define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH
struct BiosLinkerLoaderEntry {
uint32_t command;
union {
/*
* COMMAND_ALLOCATE - allocate a table from @alloc.file
* subject to @alloc.align alignment (must be power of 2)
* and @alloc.zone (can be HIGH or FSEG) requirements.
*
* Must appear exactly once for each file, and before
* this file is referenced by any other command.
*/
struct {
char file[BIOS_LINKER_LOADER_FILESZ];
uint32_t align;
uint8_t zone;
} alloc;
/*
* COMMAND_ADD_POINTER - patch the table (originating from
* @dest_file) at @pointer.offset, by adding a pointer to the table
* originating from @src_file. 1,2,4 or 8 byte unsigned
* addition is used depending on @pointer.size.
*/
struct {
char dest_file[BIOS_LINKER_LOADER_FILESZ];
char src_file[BIOS_LINKER_LOADER_FILESZ];
uint32_t offset;
uint8_t size;
} pointer;
/*
* COMMAND_ADD_CHECKSUM - calculate checksum of the range specified by
* @cksum_start and @cksum_length fields,
* and then add the value at @cksum.offset.
* Checksum simply sums -X for each byte X in the range
* using 8-bit math.
*/
struct {
char file[BIOS_LINKER_LOADER_FILESZ];
uint32_t offset;
uint32_t start;
uint32_t length;
} cksum;
/* padding */
char pad[124];
};
} QEMU_PACKED;
typedef struct BiosLinkerLoaderEntry BiosLinkerLoaderEntry;
enum {
BIOS_LINKER_LOADER_COMMAND_ALLOCATE = 0x1,
BIOS_LINKER_LOADER_COMMAND_ADD_POINTER = 0x2,
BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
};
enum {
BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1,
BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2,
};
GArray *bios_linker_loader_init(void)
{
return g_array_new(false, true /* clear */, 1);
}
/* Free linker wrapper and return the linker array. */
void *bios_linker_loader_cleanup(GArray *linker)
{
return g_array_free(linker, false);
}
void bios_linker_loader_alloc(GArray *linker,
const char *file,
uint32_t alloc_align,
bool alloc_fseg)
{
BiosLinkerLoaderEntry entry;
memset(&entry, 0, sizeof entry);
strncpy(entry.alloc.file, file, sizeof entry.alloc.file - 1);
entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ALLOCATE);
entry.alloc.align = cpu_to_le32(alloc_align);
entry.alloc.zone = cpu_to_le32(alloc_fseg ?
BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG :
BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH);
/* Alloc entries must come first, so prepend them */
g_array_prepend_vals(linker, &entry, sizeof entry);
}
void bios_linker_loader_add_checksum(GArray *linker, const char *file,
void *table,
void *start, unsigned size,
uint8_t *checksum)
{
BiosLinkerLoaderEntry entry;
memset(&entry, 0, sizeof entry);
strncpy(entry.cksum.file, file, sizeof entry.cksum.file - 1);
entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM);
entry.cksum.offset = cpu_to_le32(checksum - (uint8_t *)table);
entry.cksum.start = cpu_to_le32((uint8_t *)start - (uint8_t *)table);
entry.cksum.length = cpu_to_le32(size);
g_array_append_vals(linker, &entry, sizeof entry);
}
void bios_linker_loader_add_pointer(GArray *linker,
const char *dest_file,
const char *src_file,
GArray *table, void *pointer,
uint8_t pointer_size)
{
BiosLinkerLoaderEntry entry;
memset(&entry, 0, sizeof entry);
strncpy(entry.pointer.dest_file, dest_file,
sizeof entry.pointer.dest_file - 1);
strncpy(entry.pointer.src_file, src_file,
sizeof entry.pointer.src_file - 1);
entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_POINTER);
entry.pointer.offset = cpu_to_le32((gchar *)pointer - table->data);
entry.pointer.size = pointer_size;
assert(pointer_size == 1 || pointer_size == 2 ||
pointer_size == 4 || pointer_size == 8);
g_array_append_vals(linker, &entry, sizeof entry);
}