Add description of elf dump file in IMPLEMENTATION.
Signed-off-by: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>
---
IMPLEMENTATION | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 88 insertions(+), 0 deletions(-)
diff --git a/IMPLEMENTATION b/IMPLEMENTATION
index 2f4cfd6..0e5ad1f 100644
--- a/IMPLEMENTATION
+++ b/IMPLEMENTATION
@@ -112,3 +112,91 @@
unsigned long long page_flags; /* page flags */
} page_desc_t;
+
+* The ELF format
+ There are two different ELF format(ELF32, ELF64) for K-bit architectures (K=32,64).
+ Since they almost have the same behaviour in this situation, the following will use
+ ELF32 as a example.
+
+ - The file structure
+
+ +---------------------------------+
+ | elf_header (struct elf32_hdr) |
+ |---------------------------------+
+ | PT_NOTE (struct elf32_phdr) |
+ |---------------------------------+
+ | PT_LOAD(1) (struct elf32_phdr) |
+ | PT_LOAD(2) (struct elf32_phdr) |
+ | : |
+ | PT_LOAD(Z) (struct elf32_phdr) |
+ |---------------------------------+
+ | NOTE |
+ |---------------------------------+
+ | segment(1) |
+ | segment(2) |
+ | : |
+ | segment(Z) |
+ +---------------------------------+
+
+ - elf_header
+ This header is almost the same as a normal elf_header. The difference is that the
+ e_flags is used for indicating whether the dump file is complete or not.
+ 0x0 : complete,
+ 0x1 : incomplete
+
+ typedef struct elf32_hdr{
+ unsigned char e_ident[EI_NIDENT];
+ Elf32_Half e_type;
+ Elf32_Half e_machine;
+ Elf32_Word e_version;
+ Elf32_Addr e_entry;
+ Elf32_Off e_phoff;
+ Elf32_Off e_shoff;
+ Elf32_Word e_flags;
+ Elf32_Half e_ehsize;
+ Elf32_Half e_phentsize;
+ Elf32_Half e_phnum;
+ Elf32_Half e_shentsize;
+ Elf32_Half e_shnum;
+ Elf32_Half e_shstrndx;
+ } Elf32_Ehdr;
+
+ - PT_NOTE and PT_LOAD
+ PT_NOTE corresponds to NOTE and PT_LOAD to segment.
+ They present the corresponding NOTE and segments information.
+
+
+ typedef struct elf32_phdr{
+ Elf32_Word p_type;
+ Elf32_Off p_offset;
+ Elf32_Addr p_vaddr;
+ Elf32_Addr p_paddr;
+ Elf32_Word p_filesz;
+ Elf32_Word p_memsz;
+ Elf32_Word p_flags;
+ Elf32_Word p_align;
+ } Elf32_Phdr;
+
+ - note
+ The note structure
+
+ +------------------------------------+
+ | note header 1 (struct elf32_note) |
+ | note header 2 (struct elf32_note) |
+ | : |
+ | note header N (struct elf32_note) |
+ |------------------------------------+
+ | note data 1 |
+ | note data 2 |
+ | : |
+ | note data N |
+ +------------------------------------+
+
+ typedef struct elf32_note {
+ Elf32_Word n_namesz; /* Name size */
+ Elf32_Word n_descsz; /* Content size */
+ Elf32_Word n_type; /* Content type */
+ } Elf32_Nhdr;
+
+ - segments
+ The data dumped are all stored in segments and notes.
--
1.7.1
