Hi, Rafael,
I think "override" is more accurate. I just follow the existing
description of "ACPI_TABLE_UPGRADE" in drivers/acpi/Kconfig.
Should I change all upgrade/UPGRADE to "override/OVERRIDE" in this patch?
Thanks.
Shunyong.
On 2018/12/17 17:03, Rafael J. Wysocki wrote:
> On Mon, Dec 17, 2018 at 3:40 AM Shunyong Yang
> <shunyong.yang@xxxxxxxxxxxxxxxx> wrote:
>>
>> 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 upgrade ACPI tables from built-in initrd.
>
> What do you mean by "upgrade"?
>
>>
>> Cc: Joey Zheng <yu.zheng@xxxxxxxxxxxxxxxx>
>> Signed-off-by: Shunyong Yang <shunyong.yang@xxxxxxxxxxxxxxxx>
>> ---
>> drivers/acpi/Kconfig | 9 +++++++++
>> drivers/acpi/tables.c | 12 ++++++++++--
>> include/linux/initrd.h | 3 +++
>> 3 files changed, 22 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>> index 7cea769c37df..30976496fe77 100644
>> --- a/drivers/acpi/Kconfig
>> +++ b/drivers/acpi/Kconfig
>> @@ -357,6 +357,15 @@ config ACPI_TABLE_UPGRADE
>> initrd, therefore it's safe to say Y.
>> See Documentation/acpi/initrd_table_override.txt for details
>>
>> +config ACPI_TABLE_UPGRADE_VIA_BUILTIN_INITRD
>> + bool "Upgrade ACPI tables from built-in initrd"
>> + depends on ACPI_TABLE_UPGRADE
>> + depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION=""
>> + def_bool n
>> + help
>> + This option provides functionality to upgrade arbitrary ACPI tables
>> + from built-in uncompressed initrd.
>> +
>> config ACPI_DEBUG
>> bool "Debug Statements"
>> help
>> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
>> index 61203eebf3a1..88e3a34443da 100644
>> --- a/drivers/acpi/tables.c
>> +++ b/drivers/acpi/tables.c
>> @@ -473,14 +473,22 @@ static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
>>
>> 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_UPGRADE_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;
>>
>> diff --git a/include/linux/initrd.h b/include/linux/initrd.h
>> index 84b423044088..02d94aae54c7 100644
>> --- a/include/linux/initrd.h
>> +++ b/include/linux/initrd.h
>> @@ -22,3 +22,6 @@
>> extern void free_initrd_mem(unsigned long, unsigned long);
>>
>> extern unsigned int real_root_dev;
>> +
>> +extern char __initramfs_start[];
>> +extern unsigned long __initramfs_size;
>> --
>> 1.8.3.1
>>
>
