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Reduce size of hex0 by 3 bytes.

This commit is contained in:
Andrius Štikonas 2023-12-09 19:54:44 +00:00
parent daba916619
commit 4a1f2ba310
4 changed files with 28 additions and 40 deletions
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13
amd64/Development/hex0.M1
View File

@ -320,25 +320,22 @@ DEFINE xor_r9,r9 4D31C9
ret # return
:read_byte
push_rsp # align stack to 16 bytes
push_[rsp] # align stack to 16 bytes
and_rsp, !-16 # align stack to 16 bytes
push_rax # make sure next call is aligned to 16 bytes
mov_rcx,r12 # arg1 = fin
push !1 # size = 1
mov_rdx,rsp # arg2 = &size
push !0 # allocate stack
mov_r8,rsp # arg3 = &input
push_rsp # align stack to 16 bytes
push_[rsp] # align stack to 16 bytes
and_rsp, !-16 # align stack to 16 bytes
push_rax # make sure next call is aligned to 16 bytes
push_rax # allocate shadow stack space for UEFI function
push_rax # allocate shadow stack space for UEFI function
push_rax # allocate shadow stack space for UEFI function
call_[rcx+BYTE] !32 # fin->read()
pop_rax # deallocate stack
pop_rax # deallocate stack
pop_rax # deallocate stack
mov_rsp,[rsp+BYTE] !40 # deallocate stack
pop_rax # save input to rax
pop_rsi # save size to rsi
mov_rsp,[rsp+BYTE] !16 # deallocate stack
# If the file ended (0 bytes read) terminate
test_esi,esi # if size = 0

13
amd64/Development/hex0.S
View File

@ -243,26 +243,23 @@ write_byte:
ret # return
read_byte:
push rsp # align stack to 16 bytes
push [rsp] # align stack to 16 bytes
and rsp, -16 # align stack to 16 bytes
push rax # make sure next call is aligned to 16 bytes
mov rcx, r12 # arg1 = fin
push 1 # size = 1
mov rdx, rsp # arg2 = &size
xor esi, esi # zero rsi
push rsi # allocate stack
mov r8, rsp # arg3 = &input
push rsp # align stack to 16 bytes
push [rsp] # align stack to 16 bytes
and rsp, -16 # align stack to 16 bytes
push rax # make sure next call is aligned to 16 bytes
push rax # allocate shadow stack space for UEFI function
push rax # allocate shadow stack space for UEFI function
push rax # allocate shadow stack space for UEFI function
call [rcx+32] # fin->read()
pop rax # deallocate stack
pop rax # deallocate stack
pop rax # deallocate stack
mov rsp, [rsp+40] # deallocate stack
pop rax # save input to rax
pop rsi # save size to rsi
mov rsp, [rsp+16] # deallocate stack
# If the file ended (0 bytes read) terminate
test esi, esi # if size == 0

13
amd64/Development/hex0.hex2
View File

@ -239,25 +239,22 @@
C3 ; ret # return
:read_byte
54 ; push_rsp # align stack to 16 bytes
FF3424 ; push_[rsp] # align stack to 16 bytes
4883E4 F0 ; and_rsp, !-16 # align stack to 16 bytes
50 ; push_rax # make sure next call is aligned to 16 bytes
4C89E1 ; mov_rcx,r12 # arg1 = fin
6A 01 ; push !1 # size = 1
4889E2 ; mov_rdx,rsp # arg2 = &size
6A 00 ; push !0 # allocate stack
4989E0 ; mov_r8,rsp # arg3 = &input
54 ; push_rsp # align stack to 16 bytes
FF3424 ; push_[rsp] # align stack to 16 bytes
4883E4 F0 ; and_rsp, !-16 # align stack to 16 bytes
50 ; push_rax # make sure next call is aligned to 16 bytes
50 ; push_rax # allocate shadow stack space for UEFI function
50 ; push_rax # allocate shadow stack space for UEFI function
50 ; push_rax # allocate shadow stack space for UEFI function
FF51 20 ; call_[rcx+BYTE] !32 # fin->read()
58 ; pop_rax # deallocate stack
58 ; pop_rax # deallocate stack
58 ; pop_rax # deallocate stack
488B6424 10 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack
58 ; pop_rax # save input to rax
5E ; pop_rsi # save size to rsi
488B6424 10 ; mov_rsp,[rsp+BYTE] !16 # deallocate stack
# If the file ended (0 bytes read) terminate
85F6 ; test_esi,esi # if size = 0

29
amd64/hex0.hex0
View File

@ -129,9 +129,9 @@ F0 00 # SizeOfOptionalHeader
# [0x148]
# Start of section headers
00 00 00 00 00 00 00 00 ; Name of the section (empty) but could set to ".text"
09 02 00 00 ; VirtualSize
06 02 00 00 ; VirtualSize
00 10 00 00 ; VirtualAddress
09 02 00 00 ; SizeOfRawData
06 02 00 00 ; SizeOfRawData
70 01 00 00 ; PointerToRawData
00 00 00 00 ; PointerToRelocations
00 00 00 00 ; PointerToLinenumbers
@ -159,7 +159,7 @@ F0 00 # SizeOfOptionalHeader
# Open Loaded Image protocol
4D89F9 ; mov_r9,r15 # arg4 = image_handle
488D15 C9010000 ; lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # guid = &LOADED_IMAGE_PROTOCOL
488D15 C6010000 ; lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # guid = &LOADED_IMAGE_PROTOCOL
4C89C9 ; mov_rcx,r9 # arg1 = image_handle
50 ; push_rax # allocate stack for image
4989E0 ; mov_r8,rsp # arg3 = &image
@ -172,7 +172,7 @@ F0 00 # SizeOfOptionalHeader
# Get root file system
4D89F9 ; mov_r9,r15 # arg4 = image_handle
488D15 B4010000 ; lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # guid = &SIMPLE_FS_PROTOCOL
488D15 B1010000 ; lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # guid = &SIMPLE_FS_PROTOCOL
488B4F 18 ; mov_rcx,[rdi+BYTE] !24 # arg1 = root_device = image->device
4989CD ; mov_r13,rcx # save root_device
50 ; push_rax # allocate stack for rootfs
@ -368,25 +368,22 @@ F0 00 # SizeOfOptionalHeader
C3 ; ret # return
# :read_byte [_start+0x160]
54 ; push_rsp # align stack to 16 bytes
FF3424 ; push_[rsp] # align stack to 16 bytes
4883E4 F0 ; and_rsp, !-16 # align stack to 16 bytes
50 ; push_rax # make sure next call is aligned to 16 bytes
4C89E1 ; mov_rcx,r12 # arg1 = fin
6A 01 ; push !1 # size = 1
4889E2 ; mov_rdx,rsp # arg2 = &size
6A 00 ; push_rsi # allocate stack
4989E0 ; mov_r8,rsp # arg3 = &input
54 ; push_rsp # align stack to 16 bytes
FF3424 ; push_[rsp] # align stack to 16 bytes
4883E4 F0 ; and_rsp, !-16 # align stack to 16 bytes
50 ; push_rax # make sure next call is aligned to 16 bytes
50 ; push_rax # allocate shadow stack space for UEFI function
50 ; push_rax # allocate shadow stack space for UEFI function
50 ; push_rax # allocate shadow stack space for UEFI function
FF51 20 ; call_[rcx+BYTE] !32 # fin->read()
58 ; pop_rax # deallocate stack
58 ; pop_rax # deallocate stack
58 ; pop_rax # deallocate stack
488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack
58 ; pop_rax # save input to rax
5E ; pop_rsi # save size to rsi
488B6424 10 ; mov_rsp,[rsp+BYTE] !16 # deallocate stack
# If the file ended (0 bytes read) terminate
85F6 ; test_esi,esi # if size = 0
@ -394,7 +391,7 @@ F0 00 # SizeOfOptionalHeader
C3 ; ret # return
# :terminate [_start+0x18B]
# :terminate [_start+0x188]
4C89FC ; mov_rsp,r15 # restore stack location for cleanup
5E ; pop_rsi # restore rootdir
415F ; pop_r15 # restore image_handle
@ -437,16 +434,16 @@ F0 00 # SizeOfOptionalHeader
# Protocol GUIDs
# :LOADED_IMAGE_PROTOCOL [_start+0x1E9]
# :LOADED_IMAGE_PROTOCOL [_start+0x1E6]
A1 31 1B 5B ; %0x5b1b31a1
62 95 ; $0x9562
D2 11 ; $0x11d2
8E 3F 00 A0 C9 69 72 3B ; !0x8e !0x3f !0 !0xa0 !0xc9 !0x69 !0x72 !0x3b
# :SIMPLE_FS_PROTOCOL [_start+0x1F9]
# :SIMPLE_FS_PROTOCOL [_start+0x1F6]
22 5B 4E 96 ; %0x964e5b22
59 64 ; $0x6459
D2 11 ; $0x11d2
8E 39 00 A0 C9 69 72 3B ; !0x8e !0x39 !0 !0xa0 !0xc9 !0x69 !0x72 !0x3b
# :ELF_end [_start+0x209]
# :ELF_end [_start+0x206]