linux/arch/x86/include/uapi/asm/bootparam.h
Juergen Gross ae7e1238e6 x86/boot: Add ACPI RSDP address to setup_header
Xen PVH guests receive the address of the RSDP table from Xen. In order
to support booting a Xen PVH guest via Grub2 using the standard x86
boot entry we need a way for Grub2 to pass the RSDP address to the
kernel.

For this purpose expand the struct setup_header to hold the physical
address of the RSDP address. Being zero means it isn't specified and
has to be located the legacy way (searching through low memory or
EBDA).

While documenting the new setup_header layout and protocol version
2.14 add the missing documentation of protocol version 2.13.

There are Grub2 versions in several distros with a downstream patch
violating the boot protocol by writing past the end of setup_header.
This requires another update of the boot protocol to enable the kernel
to distinguish between a specified RSDP address and one filled with
garbage by such a broken Grub2.

From protocol 2.14 on Grub2 will write the version it is supporting
(but never a higher value than found to be supported by the kernel)
ored with 0x8000 to the version field of setup_header. This enables
the kernel to know up to which field Grub2 has written information
to. All fields after that are supposed to be clobbered.

Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: corbet@lwn.net
Cc: linux-doc@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-10 10:44:22 +02:00

254 lines
7.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _ASM_X86_BOOTPARAM_H
#define _ASM_X86_BOOTPARAM_H
/* setup_data types */
#define SETUP_NONE 0
#define SETUP_E820_EXT 1
#define SETUP_DTB 2
#define SETUP_PCI 3
#define SETUP_EFI 4
#define SETUP_APPLE_PROPERTIES 5
#define SETUP_JAILHOUSE 6
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
/* version flags */
#define VERSION_WRITTEN 0x8000
/* loadflags */
#define LOADED_HIGH (1<<0)
#define KASLR_FLAG (1<<1)
#define QUIET_FLAG (1<<5)
#define KEEP_SEGMENTS (1<<6)
#define CAN_USE_HEAP (1<<7)
/* xloadflags */
#define XLF_KERNEL_64 (1<<0)
#define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
#define XLF_EFI_HANDOVER_32 (1<<2)
#define XLF_EFI_HANDOVER_64 (1<<3)
#define XLF_EFI_KEXEC (1<<4)
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/screen_info.h>
#include <linux/apm_bios.h>
#include <linux/edd.h>
#include <asm/ist.h>
#include <video/edid.h>
/* extensible setup data list node */
struct setup_data {
__u64 next;
__u32 type;
__u32 len;
__u8 data[0];
};
struct setup_header {
__u8 setup_sects;
__u16 root_flags;
__u32 syssize;
__u16 ram_size;
__u16 vid_mode;
__u16 root_dev;
__u16 boot_flag;
__u16 jump;
__u32 header;
__u16 version;
__u32 realmode_swtch;
__u16 start_sys_seg;
__u16 kernel_version;
__u8 type_of_loader;
__u8 loadflags;
__u16 setup_move_size;
__u32 code32_start;
__u32 ramdisk_image;
__u32 ramdisk_size;
__u32 bootsect_kludge;
__u16 heap_end_ptr;
__u8 ext_loader_ver;
__u8 ext_loader_type;
__u32 cmd_line_ptr;
__u32 initrd_addr_max;
__u32 kernel_alignment;
__u8 relocatable_kernel;
__u8 min_alignment;
__u16 xloadflags;
__u32 cmdline_size;
__u32 hardware_subarch;
__u64 hardware_subarch_data;
__u32 payload_offset;
__u32 payload_length;
__u64 setup_data;
__u64 pref_address;
__u32 init_size;
__u32 handover_offset;
__u64 acpi_rsdp_addr;
} __attribute__((packed));
struct sys_desc_table {
__u16 length;
__u8 table[14];
};
/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
struct olpc_ofw_header {
__u32 ofw_magic; /* OFW signature */
__u32 ofw_version;
__u32 cif_handler; /* callback into OFW */
__u32 irq_desc_table;
} __attribute__((packed));
struct efi_info {
__u32 efi_loader_signature;
__u32 efi_systab;
__u32 efi_memdesc_size;
__u32 efi_memdesc_version;
__u32 efi_memmap;
__u32 efi_memmap_size;
__u32 efi_systab_hi;
__u32 efi_memmap_hi;
};
/*
* This is the maximum number of entries in struct boot_params::e820_table
* (the zeropage), which is part of the x86 boot protocol ABI:
*/
#define E820_MAX_ENTRIES_ZEROPAGE 128
/*
* The E820 memory region entry of the boot protocol ABI:
*/
struct boot_e820_entry {
__u64 addr;
__u64 size;
__u32 type;
} __attribute__((packed));
/*
* Smallest compatible version of jailhouse_setup_data required by this kernel.
*/
#define JAILHOUSE_SETUP_REQUIRED_VERSION 1
/*
* The boot loader is passing platform information via this Jailhouse-specific
* setup data structure.
*/
struct jailhouse_setup_data {
__u16 version;
__u16 compatible_version;
__u16 pm_timer_address;
__u16 num_cpus;
__u64 pci_mmconfig_base;
__u32 tsc_khz;
__u32 apic_khz;
__u8 standard_ioapic;
__u8 cpu_ids[255];
} __attribute__((packed));
/* The so-called "zeropage" */
struct boot_params {
struct screen_info screen_info; /* 0x000 */
struct apm_bios_info apm_bios_info; /* 0x040 */
__u8 _pad2[4]; /* 0x054 */
__u64 tboot_addr; /* 0x058 */
struct ist_info ist_info; /* 0x060 */
__u8 _pad3[16]; /* 0x070 */
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
__u8 hd1_info[16]; /* obsolete! */ /* 0x090 */
struct sys_desc_table sys_desc_table; /* obsolete! */ /* 0x0a0 */
struct olpc_ofw_header olpc_ofw_header; /* 0x0b0 */
__u32 ext_ramdisk_image; /* 0x0c0 */
__u32 ext_ramdisk_size; /* 0x0c4 */
__u32 ext_cmd_line_ptr; /* 0x0c8 */
__u8 _pad4[116]; /* 0x0cc */
struct edid_info edid_info; /* 0x140 */
struct efi_info efi_info; /* 0x1c0 */
__u32 alt_mem_k; /* 0x1e0 */
__u32 scratch; /* Scratch field! */ /* 0x1e4 */
__u8 e820_entries; /* 0x1e8 */
__u8 eddbuf_entries; /* 0x1e9 */
__u8 edd_mbr_sig_buf_entries; /* 0x1ea */
__u8 kbd_status; /* 0x1eb */
__u8 secure_boot; /* 0x1ec */
__u8 _pad5[2]; /* 0x1ed */
/*
* The sentinel is set to a nonzero value (0xff) in header.S.
*
* A bootloader is supposed to only take setup_header and put
* it into a clean boot_params buffer. If it turns out that
* it is clumsy or too generous with the buffer, it most
* probably will pick up the sentinel variable too. The fact
* that this variable then is still 0xff will let kernel
* know that some variables in boot_params are invalid and
* kernel should zero out certain portions of boot_params.
*/
__u8 sentinel; /* 0x1ef */
__u8 _pad6[1]; /* 0x1f0 */
struct setup_header hdr; /* setup header */ /* 0x1f1 */
__u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
__u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
struct boot_e820_entry e820_table[E820_MAX_ENTRIES_ZEROPAGE]; /* 0x2d0 */
__u8 _pad8[48]; /* 0xcd0 */
struct edd_info eddbuf[EDDMAXNR]; /* 0xd00 */
__u8 _pad9[276]; /* 0xeec */
} __attribute__((packed));
/**
* enum x86_hardware_subarch - x86 hardware subarchitecture
*
* The x86 hardware_subarch and hardware_subarch_data were added as of the x86
* boot protocol 2.07 to help distinguish and support custom x86 boot
* sequences. This enum represents accepted values for the x86
* hardware_subarch. Custom x86 boot sequences (not X86_SUBARCH_PC) do not
* have or simply *cannot* make use of natural stubs like BIOS or EFI, the
* hardware_subarch can be used on the Linux entry path to revector to a
* subarchitecture stub when needed. This subarchitecture stub can be used to
* set up Linux boot parameters or for special care to account for nonstandard
* handling of page tables.
*
* These enums should only ever be used by x86 code, and the code that uses
* it should be well contained and compartamentalized.
*
* KVM and Xen HVM do not have a subarch as these are expected to follow
* standard x86 boot entries. If there is a genuine need for "hypervisor" type
* that should be considered separately in the future. Future guest types
* should seriously consider working with standard x86 boot stubs such as
* the BIOS or EFI boot stubs.
*
* WARNING: this enum is only used for legacy hacks, for platform features that
* are not easily enumerated or discoverable. You should not ever use
* this for new features.
*
* @X86_SUBARCH_PC: Should be used if the hardware is enumerable using standard
* PC mechanisms (PCI, ACPI) and doesn't need a special boot flow.
* @X86_SUBARCH_LGUEST: Used for x86 hypervisor demo, lguest, deprecated
* @X86_SUBARCH_XEN: Used for Xen guest types which follow the PV boot path,
* which start at asm startup_xen() entry point and later jump to the C
* xen_start_kernel() entry point. Both domU and dom0 type of guests are
* currently supportd through this PV boot path.
* @X86_SUBARCH_INTEL_MID: Used for Intel MID (Mobile Internet Device) platform
* systems which do not have the PCI legacy interfaces.
* @X86_SUBARCH_CE4100: Used for Intel CE media processor (CE4100) SoC for
* for settop boxes and media devices, the use of a subarch for CE4100
* is more of a hack...
*/
enum x86_hardware_subarch {
X86_SUBARCH_PC = 0,
X86_SUBARCH_LGUEST,
X86_SUBARCH_XEN,
X86_SUBARCH_INTEL_MID,
X86_SUBARCH_CE4100,
X86_NR_SUBARCHS,
};
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_BOOTPARAM_H */