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prepare for selective buildLoader

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committer: jreiser <jreiser> 978897024 +0000
This commit is contained in:
John Reiser 2001-01-07 19:50:24 +00:00
parent ce1b58d293
commit 7bffc86777
1 changed files with 131 additions and 69 deletions
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200
src/stub/l_lx_elf86.asm
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@ -81,20 +81,26 @@ _start:
;;
call main ; push address of decompress subroutine
decompress:
;__LXMRU000__
jmps decompr0
;; 2+ address of decompress subroutine
;; unfilter(upx_byte *, length)
pop edx ; return address
pop eax ; upx_byte *, same as addvalue
pop ecx ; length
pusha
xchg eax,edi ; edi= pointer
pusha ; save C-convention ebx, ebp, esi, edi; also eax, edx
xchg eax, edi ; edi= pointer
push dword ('?'<<8) | 0x0f ; cto8_0f (cto8 byte is modified)
mov ebx, 'NMRU' ; modified
%ifdef __MRUBYTE0__
xor ebx, ebx ; zero
%else ;__MRUARB00__ (also __MRUBITS0__)
mov ebx, 'NMRU' ; modified N_MRU or N_MRU -1
%endif ;__LXMRU010__
xor edx,edx
xor edx, edx ; zero
jmp unf0
;__LXELF010__
; /*************************************************************************
; // C callable decompressor
@ -143,32 +149,44 @@ decompr0:
popa
ret
;__LXMRU020__
;; continuation of entry prolog for unfilter
unf0:
push edx ; tail
push ebx ; n_mru
push edx ; tail
push ebx ; n_mru or n_mru1
mov esi,esp
%define n_mru [esi]
%define n_mru1 [esi]
%define tail [esi + 4*1]
%define cto8_0f [esi + 4*2]
%define cto8 [esi + 4*2 +1]
%define addvalue [esi + 4*3 + 7*4]
%ifdef __MRUBITS1__
inc ebx ; n_mru1 ==> n_mru
%endif ;__LXMRU030__
unf1: ; allocate and clear mru[]
push edx
push edx ; zero
%ifdef __MRUBYTE1__
dec bl
%else ;__MRUARB10__
dec ebx
%endif ;__LXMRU040__
jnz unf1 ; leaves 0=='hand'
%define tmp ebp
%define jc eax
%define hand ebx
%define kh edx
%define jc eax
%define hand ebx
%define hand_l al
%define kh edx
%define kh_l dl
calltrickloop:
mov al, [edi]
inc edi
%ifndef __LXNJMP00__
sub al, 0x80 ; base of Jcc <d32>
cmp al, 0x8f - 0x80 ; span of Jcc <d32>
ja ct2 ; not Jcc <d32>
@ -180,75 +198,32 @@ calltrickloop:
dec ecx
mov byte [edi], al ; Jcc opcode
inc edi
jmps ct4
jmps mru2
ct2:
sub al, 0xE8 - 0x80 ; base of JMP/CALL <d32>
cmp al, 0xE9 - 0xE8 ; span of JMP/CALL <d32>
sub al, 0xE8 - 0x80 ; base of JMP/CALL <d32>
cmp al, 0xE9 - 0xE8 ; span of JMP/CALL <d32>
%else ;__LXNJMP10__
sub al, 0xE8 ; base of JMP/CALL <d32>
cmp al, 0xE9 - 0xE8 ; span of JMP/CALL <d32>
%endif ;__LXMRU050__
ja unfcount
ct3:
mov al, [edi]
cmp al, cto8
jnz unfcount
ct4:
mov eax, [edi]
shr ax, 8
rol eax, 16
xchg al, ah
shr jc, 1 ; eax= jc, or mru index
jnc ct6 ; not 1st time for this jc
dec hand
jge ct5
add hand, n_mru
ct5:
mov [esp + 4*hand], jc ; 1st time: mru[hand] = jc
jmps ct_store
ct6: ; not 1st time for this jc
lea kh, [jc + hand] ; kh = jc + hand
cmp kh, n_mru
jb ct7
sub kh, n_mru
ct7:
mov jc, [esp + 4*kh] ; jc = mru[kh]
dec hand
jge ct8
add hand, n_mru
ct8:
mov tmp, [esp + 4*hand] ; tmp = mru[hand]
push jc ; ran out of registers
test tmp,tmp
jnz ctmp1
mov eax, tail
dec eax
jge ct9
add eax, n_mru
ct9:
xor tmp,tmp
mov tail, eax
xchg [4+ esp + 4*eax], tmp ; tmp = mru[tail]; mru[tail] = 0
ctmp1:
pop jc
mov [esp + 4*kh ], tmp ; mru[kh] = tmp
mov [esp + 4*hand], jc ; mru[hand] = jc
ct_store:
sub eax, edi
sub ecx, byte 4
add eax, addvalue
mov [edi], eax
add edi, byte 4
je mru2
unfcount:
dec ecx
;; jg calltrickloop
db 0x0f, 0x8f
dd calltrickloop - unfdone
unfdone:
jg calltrickloop
mov edi,esp ; clear mru[] portion of stack
%ifdef __MRUBYTE2__
mov ecx, 3+ 256 ; unused, tail, ct8_0f
%elifdef __MRUBITS2__
mov ecx, n_mru1
add ecx, byte 1+ 3 ; n_mru1, tail, ct8_0f
%else ;__MRUARB20__
mov ecx, n_mru
add ecx, byte 3 ; n_mru, tail, ct8_0f
%endif ;__LXMRU060__
xor eax,eax
rep
stosd
@ -259,6 +234,93 @@ unfdone:
push edx
ret
mru2:
mov eax, [edi]
shr ax, 8
rol eax, 16
xchg al, ah
shr jc, 1 ; eax= jc, or mru index
jnc mru4 ; not 1st time for this jc
%ifdef __MRUBYTE3__
dec hand_l
%else ;__MRUARB30__
dec hand
%ifdef __MRUBITS3__
and hand, n_mru1
%else ;__MRUARB40__
jge mru3
add hand, n_mru
mru3:
%endif
%endif ;__LXMRU070__
mov [esp + 4*hand], jc ; 1st time: mru[hand] = jc
jmps mru_store
mru4: ; not 1st time for this jc
lea kh, [jc + hand] ; kh = jc + hand
%ifdef __MRUBYTE4__
movzbl kh, kh_l
%elifdef __MRUBITS4__
and kh, n_mru1
%else ;__MRUARB50__
cmp kh, n_mru
jb mru5
sub kh, n_mru
mru5:
%endif ;__LXMRU080__
mov jc, [esp + 4*kh] ; jc = mru[kh]
%ifdef __MRUBYTE5__
dec hand_l
%else ;__MRUARB60__
dec hand
%ifdef __MRUBITS5__
and hand, n_mru1
%else ;__MRUARB70__
jge mru6
add hand, n_mru
mru6:
%endif
%endif ;__LXMRU090__
mov tmp, [esp + 4*hand] ; tmp = mru[hand]
test tmp,tmp
jnz mru8
push jc ; ran out of registers
mov eax, tail
%ifdef __MRUBYTE6__
dec al
%else ;__MRUARB80__
dec eax
%ifdef __MRUBITS6__
and eax, n_mru1
%else ;__MRUARB90__
jge mru7
add eax, n_mru
mru7:
%endif
%endif ;__LXMRU100__
xor tmp,tmp
mov tail, eax
xchg [4+ esp + 4*eax], tmp ; tmp = mru[tail]; mru[tail] = 0
pop jc
mru8:
mov [esp + 4*kh ], tmp ; mru[kh] = tmp
mov [esp + 4*hand], jc ; mru[hand] = jc
mru_store:
sub eax, edi
sub ecx, byte 4
add eax, addvalue
mov [edi], eax
add edi, byte 4
jmps unfcount
;__LXELF020__
%define PAGE_MASK (~0<<12)
%define PAGE_SIZE ( 1<<12)