In some scenario, we need to build initrd with kernel in a single image.
This can simplify system deployment process by downloading the whole system
once, such as in IC verification.
This patch adds support to override ACPI tables from built-in initrd.
Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com>
[ rjw: Minor cleanups ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
via upgrading the ACPI tables provided by the BIOS with an instrumented,
modified, more recent version one, or installing brand new ACPI tables.
+When building initrd with kernel in a single image, option
+ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD should also be true for this
+feature to work.
+
For a full list of ACPI tables that can be upgraded/installed, take a look
at the char *table_sigs[MAX_ACPI_SIGNATURE]; definition in
drivers/acpi/tables.c.
initrd, therefore it's safe to say Y.
See Documentation/acpi/initrd_table_override.txt for details
+config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
+ bool "Override ACPI tables from built-in initrd"
+ depends on ACPI_TABLE_UPGRADE
+ depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION=""
+ help
+ This option provides functionality to override arbitrary ACPI tables
+ from built-in uncompressed initrd.
+
+ See Documentation/acpi/initrd_table_override.txt for details
+
config ACPI_DEBUG
bool "Debug Statements"
help
void __init acpi_table_upgrade(void)
{
- void *data = (void *)initrd_start;
- size_t size = initrd_end - initrd_start;
+ void *data;
+ size_t size;
int sig, no, table_nr = 0, total_offset = 0;
long offset = 0;
struct acpi_table_header *table;
char cpio_path[32] = "kernel/firmware/acpi/";
struct cpio_data file;
+ if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
+ data = __initramfs_start;
+ size = __initramfs_size;
+ } else {
+ data = (void *)initrd_start;
+ size = initrd_end - initrd_start;
+ }
+
if (data == NULL || size == 0)
return;
extern unsigned long phys_initrd_size;
extern unsigned int real_root_dev;
+
+extern char __initramfs_start[];
+extern unsigned long __initramfs_size;