从GRUB2获取ELF符号的热点

Question

我在内核中使用multiboot2，并试图从GRUB2获取ELF符号，但我不知道如何做到这一点。

我在boot.s中设置了.long MULTIBOOT_TAG_TYPE_ELF_SECTIONS，还从grub2中获得了elf的类型、大小、数量、entsize和shndx。

.section .multiboot_header
.align 8
multiboot_header:
  .long MULTIBOOT2_HEADER_MAGIC
  .long MULTIBOOT_ARCHITECTURE_I386
  .long multiboot_header_end - multiboot_header
  .long -(MULTIBOOT2_HEADER_MAGIC + MULTIBOOT_ARCHITECTURE_I386 + multiboot_header_end - multiboot_header)

# multiboot2 information request
.align 8
mbi_tag_start:
  .short MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST
  .short MULTIBOOT_HEADER_TAG_OPTIONAL
  .long mbi_tag_end - mbi_tag_start
  .long MULTIBOOT_TAG_TYPE_CMDLINE
  .long MULTIBOOT_TAG_TYPE_MODULE
  .long MULTIBOOT_TAG_TYPE_BOOTDEV
  .long MULTIBOOT_TAG_TYPE_MMAP
  .long MULTIBOOT_TAG_TYPE_ELF_SECTIONS
  .long MULTIBOOT_TAG_TYPE_APM
.align 8
mbi_tag_end:
    .short MULTIBOOT_HEADER_TAG_END
  .short 0
  .long 8
multiboot_header_end:

struct multiboot_tag_elf_sections {
    multiboot_uint32_t type;
    multiboot_uint32_t size;
    multiboot_uint32_t num;
    multiboot_uint32_t entsize;
    multiboot_uint32_t shndx;
    char sections[0];
};

Answer 1

在多引导信息中搜索带有type=9的标记。