elf형식 파일 읽기 기능 추가

23.12.03 최초 작성

• /ui/input.h : Elf64Hdr 구조체 추가

---

#include <stdint.h>

typedef struct {
  uint8_t     e_ident[16];         /* Magic number and other info */
  uint16_t    e_type;              /* Object file type */
  uint16_t    e_machine;           /* Architecture */
  uint32_t    e_version;           /* Object file version */
  uint64_t    e_entry;             /* Entry point virtual address */
  uint64_t    e_phoff;             /* Program header table file offset */
  uint64_t    e_shoff;             /* Section header table file offset */
  uint32_t    e_flags;             /* Processor-specific flags */
  uint16_t    e_ehsize;            /* ELF header size in bytes */
  uint16_t    e_phentsize;         /* Program header table entry size */
  uint16_t    e_phnum;             /* Program header table entry count */
  uint16_t    e_shentsize;         /* Section header table entry size */
  uint16_t    e_shnum;             /* Section header table entry count */
  uint16_t    e_shstrndx;          /* Section header string table index */
} Elf64Hdr;

---

• /ui/input.c : elf 명령 입력 시 ./sample/sample.elf파일의 형식 모니터에 출력하는 코드 추가

---

#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <execinfo.h>

...

int toy_read_elf_header(char **args);

...

char *builtin_str[] = {
    "send",
    "mu",
    "sh",
    "mq",
    "elf",
    "exit"
};

int (*builtin_func[]) (char **) = {
    &toy_send,
    &toy_mutex,
    &toy_shell,
    &toy_message_queue,
    &toy_read_elf_header,
    &toy_exit
};

...
//	지정된 경로의 elf파일을 읽어 모니터에 출력하는 코드
int toy_read_elf_header(char **args)
{
    int mqretcode;
    toy_msg_t msg;
    int in_fd;
    char *contents = NULL;
    size_t contents_sz;
    struct stat st;
    Elf64Hdr *map;

    in_fd = open("./sample/sample.elf", O_RDONLY);

	if ( in_fd < 0 ) {
        perror("File is not available");
        return 0;
    }
    if (fstat(in_fd, &st) == 0) {

        map = (Elf64Hdr *)mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, in_fd, 0);
        if(map == MAP_FAILED){
            perror("mmap failed : read_elf");
            exit(0);
        }
        printf("file type : %d\n", map->e_type);
        printf("Architecture : %d\n", map->e_machine);
        printf("file version : %d\n", map->e_version);
        printf("virtual address : %ld\n", map->e_entry);
        printf("header table file offset : %ld\n", map->e_phoff);
        munmap(map, contents_sz);
    }


    return 1;
}

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