[PATCH v2 01/16] x86: Update the bootparam header

[Bin Meng]

+Andy Shevchenko

On Sun, Aug 30, 2020 at 5:42 AM Simon Glass <sjg at chromium.org> wrote:
>
> This header is missing a few of the newer features from the specification.
> Add these as well as a link to the spec. Also use the BIT() macros where
> appropriate.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
> ---
>
> (no changes since v1)
>
>  arch/x86/include/asm/bootparam.h | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
> index d961dddc9e1..7a3c1f51554 100644
> --- a/arch/x86/include/asm/bootparam.h
> +++ b/arch/x86/include/asm/bootparam.h
> @@ -24,6 +24,11 @@ struct setup_data {
>         __u8 data[0];
>  };
>
> +/**
> + * struct setup_header - Information needed by Linux to boot
> + *
> + * See https://www.kernel.org/doc/html/latest/x86/boot.html

Now I am confused. This kernel document says:

Protocol 2.14 BURNT BY INCORRECT COMMIT
ae7e1238e68f2a472a125673ab506d49158c1889 (x86/boot: Add ACPI RSDP
address to setup_header) DO NOT USE!!! ASSUME SAME AS 2.13.

However in U-Boot there was a commit from Andy saying that:

commit d905aa8a4277e200e11fdf6d73a7c76d0e6f34a4 (<=== U-Boot commit)
Author: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Date:   Fri Sep 13 18:42:00 2019 +0300

    x86: zImage: Propagate acpi_rsdp_addr to kernel via boot parameters

...

    after upstream got eventually the Linux kernel

    commit e6e094e053af75cbc164e950814d3d084fb1e698
    Author: Juergen Gross <jgross at suse.com>
    Date:   Tue Nov 20 08:25:29 2018 +0100

        x86/acpi, x86/boot: Take RSDP address from boot params if available

So there are 2 commits in the Linux kernel that do the same thing, one
in boot_params, the other one in setup_header?

e6e094e053af75cbc164e950814d3d084fb1e698 : x86/acpi, x86/boot: Take
RSDP address from boot params if available
ae7e1238e68f2a472a125673ab506d49158c1889 : x86/boot: Add ACPI RSDP
address to setup_header

> + */
>  struct setup_header {
>         __u8    setup_sects;
>         __u16   root_flags;
> @@ -43,15 +48,16 @@ struct setup_header {
>         __u16   kernel_version;
>         __u8    type_of_loader;
>         __u8    loadflags;
> -#define LOADED_HIGH    (1<<0)
> -#define QUIET_FLAG     (1<<5)
> -#define KEEP_SEGMENTS  (1<<6)
> -#define CAN_USE_HEAP   (1<<7)
> +#define LOADED_HIGH    BIT(0)
> +#define KASLR_FLAG     BIT(1)
> +#define QUIET_FLAG     BIT(5)
> +#define KEEP_SEGMENTS  BIT(6)          /* Obsolete */
> +#define CAN_USE_HEAP   BIT(7)
>         __u16   setup_move_size;
>         __u32   code32_start;
>         __u32   ramdisk_image;
>         __u32   ramdisk_size;
> -       __u32   bootsect_kludge;
> +       __u32   bootsect_kludge;        /* Obsolete */
>         __u16   heap_end_ptr;
>         __u8    ext_loader_ver;
>         __u8    ext_loader_type;
> @@ -59,7 +65,13 @@ struct setup_header {
>         __u32   initrd_addr_max;
>         __u32   kernel_alignment;
>         __u8    relocatable_kernel;
> -       __u8    _pad2[3];
> +       u8      min_alignment;
> +#define XLF_KERNEL_64                  BIT(0)
> +#define XLF_CAN_BE_LOADED_ABOVE_4G     BIT(1)
> +#define XLF_EFI_HANDOVER_32            BIT(2)
> +#define XLF_EFI_HANDOVER_64            BIT(3)
> +#define XLF_EFI_KEXEC                  BIT(4)
> +       u16     xloadflags;
>         __u32   cmdline_size;
>         __u32   hardware_subarch;
>         __u64   hardware_subarch_data;
> @@ -69,6 +81,7 @@ struct setup_header {
>         __u64   pref_address;
>         __u32   init_size;
>         __u32   handover_offset;
> +       u32     kernel_info_offset;
>  } __attribute__((packed));
>
>  struct sys_desc_table {

Regards,
Bin