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
>
