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refine pseudo-sections

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committer: jreiser <jreiser> 978901287 +0000
This commit is contained in:
John Reiser 2001-01-07 21:01:27 +00:00
parent 7bffc86777
commit c9a36d51c4
1 changed files with 24 additions and 12 deletions
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32
src/stub/l_lx_elf86.asm
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@ -54,6 +54,14 @@
%include "ident.ash" %include "ident.ash"
;;;; names of pseudo-sections for addLoader:
;; LXUNFnnn Linux unfilter
;; LXNJMPnn omit filtering of 6-byte Jxx (0x0f 0x80..0x8f)
;; LXMRUnnn MostRecentlyUsed recoding of destinations
;; MRUARBnn arbitrary number of entries in wheel
;; MRUBITSn power of 2 entries in wheel (smaller code)
;; MRUBYTEn 256 entries in wheel (smallest code)
; /************************************************************************* ; /*************************************************************************
; // program entry point ; // program entry point
; // see glibc/sysdeps/i386/elf/start.S ; // see glibc/sysdeps/i386/elf/start.S
@ -81,7 +89,7 @@ _start:
;; ;;
call main ; push address of decompress subroutine call main ; push address of decompress subroutine
decompress: decompress:
;__LXMRU000__ ;__LXUNF000__
jmps decompr0 jmps decompr0
;; 2+ address of decompress subroutine ;; 2+ address of decompress subroutine
;; unfilter(upx_byte *, length) ;; unfilter(upx_byte *, length)
@ -99,7 +107,8 @@ decompress:
%endif ;__LXMRU010__ %endif ;__LXMRU010__
xor edx, edx ; zero xor edx, edx ; zero
jmp unf0 ;__LXUNF010__
jmpn unf0
;__LXELF010__ ;__LXELF010__
; /************************************************************************* ; /*************************************************************************
@ -149,11 +158,13 @@ decompr0:
popa popa
ret ret
;__LXMRU020__ ;__LXUNF020__
;; continuation of entry prolog for unfilter ;; continuation of entry prolog for unfilter
unf0: unf0:
;__LXMRU020__
push edx ; tail push edx ; tail
push ebx ; n_mru or n_mru1 push ebx ; n_mru or n_mru1
;__LXUNF025__
mov esi, esp mov esi, esp
%define n_mru [esi] %define n_mru [esi]
@ -183,6 +194,7 @@ unf1: ; allocate and clear mru[]
%define kh edx %define kh edx
%define kh_l dl %define kh_l dl
;__LXUNF030__
calltrickloop: calltrickloop:
mov al, [edi] mov al, [edi]
inc edi inc edi
@ -198,7 +210,7 @@ calltrickloop:
dec ecx dec ecx
mov byte [edi], al ; Jcc opcode mov byte [edi], al ; Jcc opcode
inc edi inc edi
jmps mru2 jmps lxunf
ct2: ct2:
sub al, 0xE8 - 0x80 ; base of JMP/CALL <d32> sub al, 0xE8 - 0x80 ; base of JMP/CALL <d32>
cmp al, 0xE9 - 0xE8 ; span of JMP/CALL <d32> cmp al, 0xE9 - 0xE8 ; span of JMP/CALL <d32>
@ -209,7 +221,7 @@ ct2:
ja unfcount ja unfcount
mov al, [edi] mov al, [edi]
cmp al, cto8 cmp al, cto8
je mru2 je lxunf
unfcount: unfcount:
dec ecx dec ecx
jg calltrickloop jg calltrickloop
@ -234,12 +246,12 @@ unfcount:
push edx push edx
ret ret
mru2: lxunf:
mov eax, [edi] mov eax, [edi]
shr ax, 8 shr ax, 8
rol eax, 16 rol eax, 16
xchg al, ah xchg al, ah
;__LXMRU065__
shr jc, 1 ; eax= jc, or mru index shr jc, 1 ; eax= jc, or mru index
jnc mru4 ; not 1st time for this jc jnc mru4 ; not 1st time for this jc
%ifdef __MRUBYTE3__ %ifdef __MRUBYTE3__
@ -256,7 +268,7 @@ mru3:
%endif ;__LXMRU070__ %endif ;__LXMRU070__
mov [esp + 4*hand], jc ; 1st time: mru[hand] = jc mov [esp + 4*hand], jc ; 1st time: mru[hand] = jc
jmps mru_store jmps unf_store
mru4: ; not 1st time for this jc mru4: ; not 1st time for this jc
lea kh, [jc + hand] ; kh = jc + hand lea kh, [jc + hand] ; kh = jc + hand
@ -311,8 +323,8 @@ mru7:
mru8: mru8:
mov [esp + 4*kh ], tmp ; mru[kh] = tmp mov [esp + 4*kh ], tmp ; mru[kh] = tmp
mov [esp + 4*hand], jc ; mru[hand] = jc mov [esp + 4*hand], jc ; mru[hand] = jc
;__LXUNF040__
mru_store: unf_store:
sub eax, edi sub eax, edi
sub ecx, byte 4 sub ecx, byte 4
add eax, addvalue add eax, addvalue