    /*
     * Permission is hereby granted, free of charge, to any person obtaining a copy
     * of this software and associated documentation files (the "Software"), to
     * deal in the Software without restriction, including without limitation the
     * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     * sell copies of the Software, and to permit persons to whom the Software is
     * furnished to do so, subject to the following conditions:
     *
     * The above copyright notice and this permission notice shall be included in
     * all copies or substantial portions of the Software.
     *
     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     * DEALINGS IN THE SOFTWARE.
     *
     * Copyright (c) 2016, Citrix Systems, Inc.
     */

    #ifndef __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__
    #define __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__

    /*
     * Start of day structure passed to PVH guests and to HVM guests in %ebx.
     *
     * NOTE: nothing will be loaded at physical address 0, so a 0 value in any
     * of the address fields should be treated as not present.
     *
     *  0 +----------------+
     *    | magic          | Contains the magic value XEN_HVM_START_MAGIC_VALUE
     *    |                | ("xEn3" with the 0x80 bit of the "E" set).
     *  4 +----------------+
     *    | version        | Version of this structure. Current version is 1. New
     *    |                | versions are guaranteed to be backwards-compatible.
     *  8 +----------------+
     *    | flags          | SIF_xxx flags.
     * 12 +----------------+
     *    | nr_modules     | Number of modules passed to the kernel.
     * 16 +----------------+
     *    | modlist_paddr  | Physical address of an array of modules
     *    |                | (layout of the structure below).
     * 24 +----------------+
     *    | cmdline_paddr  | Physical address of the command line,
     *    |                | a zero-terminated ASCII string.
     * 32 +----------------+
     *    | rsdp_paddr     | Physical address of the RSDP ACPI data structure.
     * 40 +----------------+
     *    | memmap_paddr   | Physical address of the (optional) memory map. Only
     *    |                | present in version 1 and newer of the structure.
     * 48 +----------------+
     *    | memmap_entries | Number of entries in the memory map table. Zero
     *    |                | if there is no memory map being provided. Only
     *    |                | present in version 1 and newer of the structure.
     * 52 +----------------+
     *    | reserved       | Version 1 and newer only.
     * 56 +----------------+
     *
     * The layout of each entry in the module structure is the following:
     *
     *  0 +----------------+
     *    | paddr          | Physical address of the module.
     *  8 +----------------+
     *    | size           | Size of the module in bytes.
     * 16 +----------------+
     *    | cmdline_paddr  | Physical address of the command line,
     *    |                | a zero-terminated ASCII string.
     * 24 +----------------+
     *    | reserved       |
     * 32 +----------------+
     *
     * The layout of each entry in the memory map table is as follows:
     *
     *  0 +----------------+
     *    | addr           | Base address
     *  8 +----------------+
     *    | size           | Size of mapping in bytes
     * 16 +----------------+
     *    | type           | Type of mapping as defined between the hypervisor
     *    |                | and guest. See XEN_HVM_MEMMAP_TYPE_* values below.
     * 20 +----------------|
     *    | reserved       |
     * 24 +----------------+
     *
     * The address and sizes are always a 64bit little endian unsigned integer.
     *
     * NB: Xen on x86 will always try to place all the data below the 4GiB
     * boundary.
     *
     * Version numbers of the hvm_start_info structure have evolved like this:
     *
     * Version 0:  Initial implementation.
     *
     * Version 1:  Added the memmap_paddr/memmap_entries fields (plus 4 bytes of
     *             padding) to the end of the hvm_start_info struct. These new
     *             fields can be used to pass a memory map to the guest. The
     *             memory map is optional and so guests that understand version 1
     *             of the structure must check that memmap_entries is non-zero
     *             before trying to read the memory map.
     */
    #define XEN_HVM_START_MAGIC_VALUE 0x336ec578

    /*
     * The values used in the type field of the memory map table entries are
     * defined below and match the Address Range Types as defined in the "System
     * Address Map Interfaces" section of the ACPI Specification. Please refer to
     * section 15 in version 6.2 of the ACPI spec: http://uefi.org/specifications
     */
    #define XEN_HVM_MEMMAP_TYPE_RAM       1
    #define XEN_HVM_MEMMAP_TYPE_RESERVED  2
    #define XEN_HVM_MEMMAP_TYPE_ACPI      3
    #define XEN_HVM_MEMMAP_TYPE_NVS       4
    #define XEN_HVM_MEMMAP_TYPE_UNUSABLE  5
    #define XEN_HVM_MEMMAP_TYPE_DISABLED  6
    #define XEN_HVM_MEMMAP_TYPE_PMEM      7

    /*
     * C representation of the x86/HVM start info layout.
     *
     * The canonical definition of this layout is above, this is just a way to
     * represent the layout described there using C types.
     */
    struct hvm_start_info {
        uint32_t magic;             /* Contains the magic value 0x336ec578       */
                                    /* ("xEn3" with the 0x80 bit of the "E" set).*/
        uint32_t version;           /* Version of this structure.                */
        uint32_t flags;             /* SIF_xxx flags.                            */
        uint32_t nr_modules;        /* Number of modules passed to the kernel.   */
        uint64_t modlist_paddr;     /* Physical address of an array of           */
                                    /* hvm_modlist_entry.                        */
        uint64_t cmdline_paddr;     /* Physical address of the command line.     */
        uint64_t rsdp_paddr;        /* Physical address of the RSDP ACPI data    */
                                    /* structure.                                */
        /* All following fields only present in version 1 and newer */
        uint64_t memmap_paddr;      /* Physical address of an array of           */
                                    /* hvm_memmap_table_entry.                   */
        uint32_t memmap_entries;    /* Number of entries in the memmap table.    */
                                    /* Value will be zero if there is no memory  */
                                    /* map being provided.                       */
        uint32_t reserved;          /* Must be zero.                             */
    };

    struct hvm_modlist_entry {
        uint64_t paddr;             /* Physical address of the module.           */
        uint64_t size;              /* Size of the module in bytes.              */
        uint64_t cmdline_paddr;     /* Physical address of the command line.     */
        uint64_t reserved;
    };

    struct hvm_memmap_table_entry {
        uint64_t addr;              /* Base address of the memory region         */
        uint64_t size;              /* Size of the memory region in bytes        */
        uint32_t type;              /* Mapping type                              */
        uint32_t reserved;          /* Must be zero for Version 1.               */
    };

    #endif /* __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__ */