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lib32: add .dynsym section
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@mewmew
mewmew committed Mar 19, 2019
1 parent 3fc4757 commit 82632c5
Showing 1 changed file with 83 additions and 47 deletions.
130 changes: 83 additions & 47 deletions lib_elf32.asm
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Original file line number Diff line number Diff line change
Expand Up @@ -172,13 +172,56 @@ db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x01,
; 00000110
db 0x01, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00 ; |................|
; 00000120
db 0x01, 0x00, 0x00, 0x00, 0x89, 0x73, 0x88, 0x0b, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ; |.....s..........|
; 00000130
db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00 ; |................|
; 00000140
db 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x05, 0x00
db 0x01, 0x00, 0x00, 0x00, 0x89, 0x73, 0x88, 0x0b

; 00000140

; --- [ .dynsym section ] ------------------------------------------------------

dynsym_off equ $ - BASE_R_SEG

STT_NOTYPE equ 0 ; Unspecified type.
STT_FUNC equ 2 ; Function.

STB_LOCAL equ 0 ; Local symbol
STB_GLOBAL equ 1 ; Global symbol

STV_DEFAULT equ 0 ; Default visibility (see binding).

; 00000128

dynsym:

; Num: Value Size Type Bind Vis Ndx Name
; 0: 00000000 0 NOTYPE LOCAL DEFAULT UND

.null:
dd dynstr.null_off ; name: String table index of name.
dd 0 ; value: Symbol value.
dd 0 ; size: Size of associated object.
db STB_LOCAL<<4 | STT_NOTYPE ; info: Type and binding information.
db STV_DEFAULT ; other: Reserved (not used).
dw 0 ; shndx: Section index of symbol.

.entsize equ $ - dynsym

; Num: Value Size Type Bind Vis Ndx Name
; 1: 00001000 0 NOTYPE GLOBAL DEFAULT 5 foo

; TODO: figure out why section index 5 (i.e. .eh_frame_idx) is used.

.foo:
dd dynstr.foo_off ; name: String table index of name.
dd 0x1000 ; value: Symbol value.
dd 0 ; size: Size of associated object.
db STB_GLOBAL<<4 | STT_NOTYPE ; info: Type and binding information.
db STV_DEFAULT ; other: Reserved (not used).
dw shdr.eh_frame_idx ; shndx: Section index of symbol.

.foo_idx equ (.foo - dynsym) / .entsize

dynsym.size equ $ - dynsym

; --- [/ .dynsym section ] -----------------------------------------------------

; --- [ .dynstr section ] ------------------------------------------------------

Expand All @@ -194,8 +237,8 @@ dynstr:
.foo:
db "foo", 0

.null_off equ .null - dynstr ; 0
.foo_off equ .foo - dynstr ; 1
.null_off equ .null - dynstr ; 0
.foo_off equ .foo - dynstr ; 1

dynstr.size equ $ - dynstr

Expand Down Expand Up @@ -324,8 +367,6 @@ gnu_hash equ 0x108 ; TODO: remove
; Tag Type Name/Value
; 0x00000006 (SYMTAB) 0x128

dynsym equ 0x128 ; TODO: remove

.symtab:
dd DT_SYMTAB ; tag: Entry type.
dd dynsym ; val: Integer/Address value.
Expand Down Expand Up @@ -374,25 +415,25 @@ shstrtab:
.null:
db 0

.shstrtab_idx equ $ - shstrtab
.shstrtab_off equ $ - shstrtab
db ".shstrtab", 0

.gnu_hash_idx equ $ - shstrtab
.gnu_hash_off equ $ - shstrtab
db ".gnu.hash", 0

.dynsym_idx equ $ - shstrtab
.dynsym_off equ $ - shstrtab
db ".dynsym", 0

.dynstr_idx equ $ - shstrtab
.dynstr_off equ $ - shstrtab
db ".dynstr", 0

.text_idx equ $ - shstrtab
.text_off equ $ - shstrtab
db ".text", 0

.eh_frame_idx equ $ - shstrtab
.eh_frame_off equ $ - shstrtab
db ".eh_frame", 0

.dynamic_idx equ $ - shstrtab
.dynamic_off equ $ - shstrtab
db ".dynamic", 0

shstrtab.size equ $ - shstrtab
Expand Down Expand Up @@ -449,7 +490,7 @@ gnu_hash.size equ 0x20 ; TODO: remove
gnu_hash.entsize equ 4 ; TODO: remove

.gnu_hash:
dd shstrtab.gnu_hash_idx ; name: Section name (index into the section header string table).
dd shstrtab.gnu_hash_off ; name: Section name (index into the section header string table).
dd SHT_GNU_HASH ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd gnu_hash ; addr: Address in memory image.
Expand All @@ -463,43 +504,38 @@ gnu_hash.entsize equ 4 ; TODO: remove
; [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
; [ 2] .dynsym DYNSYM 00000128 000128 000020 10 A 3 1 4

dynsym equ 0x128 ; TODO: remove
dynsym_off equ 0x128 ; TODO: remove
dynsym.size equ 0x20 ; TODO: remove
dynsym.entsize equ 0x10 ; TODO: remove

.dynsym:
dd shstrtab.dynsym_idx ; name: Section name (index into the section header string table).
dd SHT_DYNSYM ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd dynsym ; addr: Address in memory image.
dd dynsym_off ; off: Offset in file.
dd dynsym.size ; size: Size in bytes.
dd shdr.dynstr_idx ; link: Index of a related section.
dd shdr.gnu_hash_idx ; info: Depends on section type.
dd 0x4 ; addralign: Alignment in bytes.
dd dynsym.entsize ; entsize: Size of each entry in section.
dd shstrtab.dynsym_off ; name: Section name (index into the section header string table).
dd SHT_DYNSYM ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd dynsym ; addr: Address in memory image.
dd dynsym_off ; off: Offset in file.
dd dynsym.size ; size: Size in bytes.
dd shdr.dynstr_idx ; link: Index of a related section.
dd shdr.gnu_hash_idx ; info: Depends on section type.
dd 0x4 ; addralign: Alignment in bytes.
dd dynsym.entsize ; entsize: Size of each entry in section.

; [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
; [ 3] .dynstr STRTAB 00000148 000148 000005 00 A 0 0 1

.dynstr:
dd shstrtab.dynstr_idx ; name: Section name (index into the section header string table).
dd SHT_STRTAB ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd dynstr ; addr: Address in memory image.
dd dynstr_off ; off: Offset in file.
dd dynstr.size ; size: Size in bytes.
dd 0 ; link: Index of a related section.
dd 0 ; info: Depends on section type.
dd 0x1 ; addralign: Alignment in bytes.
dd 0 ; entsize: Size of each entry in section.
dd shstrtab.dynstr_off ; name: Section name (index into the section header string table).
dd SHT_STRTAB ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd dynstr ; addr: Address in memory image.
dd dynstr_off ; off: Offset in file.
dd dynstr.size ; size: Size in bytes.
dd 0 ; link: Index of a related section.
dd 0 ; info: Depends on section type.
dd 0x1 ; addralign: Alignment in bytes.
dd 0 ; entsize: Size of each entry in section.

; [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
; [ 4] .text PROGBITS 00001000 001000 000006 00 AX 0 0 16

.text:
dd shstrtab.text_idx ; name: Section name (index into the section header string table).
dd shstrtab.text_off ; name: Section name (index into the section header string table).
dd SHT_PROGBITS ; type: Section type.
dd SHF_ALLOC | SHF_EXECINSTR ; flags: Section flags.
dd text ; addr: Address in memory image.
Expand All @@ -514,7 +550,7 @@ dynsym.entsize equ 0x10 ; TODO: remove
; [ 5] .eh_frame PROGBITS 00002000 002000 000000 00 A 0 0 4

.eh_frame:
dd shstrtab.eh_frame_idx ; name: Section name (index into the section header string table).
dd shstrtab.eh_frame_off ; name: Section name (index into the section header string table).
dd SHT_PROGBITS ; type: Section type.
dd SHF_ALLOC ; flags: Section flags.
dd eh_frame ; addr: Address in memory image.
Expand All @@ -529,7 +565,7 @@ dynsym.entsize equ 0x10 ; TODO: remove
; [ 6] .dynamic DYNAMIC 00002fa0 002fa0 000060 08 WA 3 0 4

.dynamic:
dd shstrtab.dynamic_idx ; name: Section name (index into the section header string table).
dd shstrtab.dynamic_off ; name: Section name (index into the section header string table).
dd SHT_DYNAMIC ; type: Section type.
dd SHF_WRITE | SHF_ALLOC ; flags: Section flags.
dd dynamic ; addr: Address in memory image.
Expand All @@ -544,7 +580,7 @@ dynsym.entsize equ 0x10 ; TODO: remove
; [ 7] .shstrtab STRTAB 00000000 003000 00003e 00 0 0 1

.shstrtab:
dd shstrtab.shstrtab_idx ; name: Section name (index into the section header string table).
dd shstrtab.shstrtab_off ; name: Section name (index into the section header string table).
dd SHT_STRTAB ; type: Section type.
dd 0x0 ; flags: Section flags.
dd 0 ; addr: Address in memory image.
Expand Down

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