LC_SEGMENT

• LC_SEGMENT
  • 含义：Defines a segment of this file to be mapped into the address space of the process that loads this file. It also includes all the sections contained by the segment.
  • 数据结构定义：segment_command

segment_command定义

• 精简定义

struct segment_command {
  uint32_t  cmd;
  uint32_t  cmdsize;
  char      segname[16];
  uint32_t  vmaddr;
  uint32_t  vmsize;
  uint32_t  fileoff;
  uint32_t  filesize;
  vm_prot_t maxprot;
  vm_prot_t initprot;
  uint32_t  nsects;
  uint32_t  flags;
};

• 完整定义

/*
 * The segment load command indicates that a part of this file is to be
 * mapped into the task's address space.  The size of this segment in memory,
 * vmsize, maybe equal to or larger than the amount to map from this file,
 * filesize.  The file is mapped starting at fileoff to the beginning of
 * the segment in memory, vmaddr.  The rest of the memory of the segment,
 * if any, is allocated zero fill on demand.  The segment's maximum virtual
 * memory protection and initial virtual memory protection are specified
 * by the maxprot and initprot fields.  If the segment has sections then the
 * section structures directly follow the segment command and their size is
 * reflected in cmdsize.
 */
struct segment_command { /* for 32-bit architectures */
    uint32_t    cmd;        /* LC_SEGMENT */
    uint32_t    cmdsize;    /* includes sizeof section structs */
    char        segname[16];    /* segment name */
    uint32_t    vmaddr;        /* memory address of this segment */
    uint32_t    vmsize;        /* memory size of this segment */
    uint32_t    fileoff;    /* file offset of this segment */
    uint32_t    filesize;    /* amount to map from the file */
    vm_prot_t    maxprot;    /* maximum VM protection */
    vm_prot_t    initprot;    /* initial VM protection */
    uint32_t    nsects;        /* number of sections in segment */
    uint32_t    flags;        /* flags */
};