asinfo

The asinfo section consists of an array of the following structure. Each entry describes the attributes of one section of address space on the machine.

struct asinfo_entry {
    uint64_t            start;
    uint64_t            end;
    uint16_t            owner;
    uint16_t            name;
    uint16_t            attr;
    uint16_t            priority;
    int                 (*alloc_checker)(struct syspage_entry *__sp, 
                                     uint64_t   *__base,
                                     uint64_t   *__len,
                                     size_t     __size,
                                     size_t     __align);
    uint32_t            spare;
};

Member	Description
`start`	Gives the first physical address of the range being described.
`end`	Gives the last physical address of the range being described. Note that this is the actual last byte, not one beyond the end.
`owner`	An offset from the start of the section giving the owner of this entry (its "parent" in the tree). It's set to AS_NULL_OFF if the entry doesn't have an owner (it's at the "root" of the address space tree).
`name`	An offset from the start of the `strings` section of the system page giving the string name of this entry.
`attr`	Contains several bits affecting the address range (see below).
`priority`	Indicates the speed of the memory in the address range. Lower numbers mean slower memory. The macro AS_PRIORITY_DEFAULT is defined to use a default value for this field (currently defined as 100).

Note: The alloc_checker isn't currently used. When implemented, it will let you provide finer-grain control over how the system allocates memory (e.g. making sure that ISA memory used for DMA doesn't cross 64 KB boundaries).