# SPDX-FileCopyrightText: 2022 Andrius Štikonas # SPDX-FileCopyrightText: 2019 Jeremiah Orians # # SPDX-License-Identifier: GPL-3.0-or-later :PE32_base # DOS MZ header 4D 5A # Signature 00 00 # Number of bytes in the last page. 00 00 # Number of whole/partial pages 00 00 # Number of entries in the relocation table. 00 00 # Header size 00 00 # Minimum allocation 00 00 # Maximum allocation 00 00 # Relocatable segment address for SS 00 00 # Initial value for SP 00 00 # Checksum (I don't think is looked at) 00 00 # Initial value for IP (Seems ignored) 00 00 # Relocatable segment address for CS (Seems ignored) 00 00 # The (absolute) offset to the relocation table. 00 00 # Value used for overlay management. If zero, this is the main executable 00 00 00 00 00 00 00 00 # Reserved in PE 00 00 # OEM identifier 00 00 # OEM info 00 00 00 00 00 00 00 00 00 00 # The required reserved 20 bytes of NULLS 00 00 00 00 00 00 00 00 00 00 40 00 00 00 # Starting address of the PE header # [0x40] :PE_header 50 45 00 00 # Signature "PE" 64 86 # Machine 01 00 # number of sections 00 00 00 00 # Timestamp supposedly 00 00 00 00 # PointerToSymbolTable 00 00 00 00 # number of symbols @OptionalHeader_end>PE_header # SizeOfOptionalHeader 00 00 # 'Characteristics' # [0x58] # COFF header bits 0B 02 # Magic PE32+ (64 bit) 00 00 # Linker version 00 00 00 00 # size of code 00 00 00 00 # sizeOfInitializedData 00 00 00 00 # SizeOfUninitializedData 00 10 00 00 # AddressOfEntryPoint 00 00 00 00 # BaseOfCode 00 00 00 00 00 00 00 00 # ImageBase 01 00 00 00 # SectionAlignment 01 00 00 00 # FileAlignment 00 00 00 00 # OperatingSystemVersion 00 00 00 00 # ImageVersion 00 00 00 00 # SubsystemVersion 00 00 00 00 # Win32VersionValue 00 00 10 00 # SizeOfImage %PE32_text>PE32_base # SizeOfHeaders 00 00 00 00 # CheckSum (isn't used at all) 0A 00 # Subsystem 00 00 # DllCharacteristics 00 00 00 00 # SizeOfStackReserve 00 00 00 00 # SizeOfStackCommit 00 00 00 00 # SizeOfHeapReserve 00 00 00 00 # SizeOfHeapCommit 00 00 00 00 # LoaderFlags 00 00 00 00 # NumberOfRvaAndSizes # [0xB8] # Data directories (has to be 16 entries always 16bytes per entry) 00 00 00 00 # Export Table 00 00 00 00 # Size of Export Table 00 00 00 00 # Import Table 10 00 00 00 # Size of Import Table 00 00 00 00 # Resource Table 00 00 00 00 # Size of Resource Table 00 00 00 00 # Exception Table 00 00 00 00 # Size of Exception Table 00 00 00 00 # Certificate Table 00 00 00 00 # Size of Certificate Table 00 00 00 00 # Base Relocation Table 00 00 00 00 # Size of Base Relocation Table 00 00 00 00 # Debug Table 00 00 00 00 # Size of Debug Table 00 00 00 00 # Architecture Data Table 00 00 00 00 # Size of Architecture Data Table 00 00 00 00 # Global Pointer 00 00 00 00 # NULL 00 00 00 00 # TLS Table 00 00 00 00 # Size of TLS Table 00 00 00 00 # Load Config Table 00 00 00 00 # Size of Load Config Table 00 00 00 00 # Bound Import Table 00 00 00 00 # Size of Bound Import Table 00 00 00 00 # Import Address Table 00 00 00 00 # Size of Import Address Table 00 00 00 00 # Delay Import Descriptor Table 00 00 00 00 # Size of Delay Import Descriptor Table 00 00 00 00 # CLR Runtime header table 00 00 00 00 # Size of CLR Runtime Header table # [0x130] :OptionalHeader_end 00 00 00 00 00 00 00 00 # MUST BE NULL # no idea what it is yet 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # [0x148] # Start of section headers 2E 74 65 78 74 00 00 00 ; Name of the section: ".text" %ELF_end>PE32_text ; VirtualSize 00 10 00 00 ; VirtualAddress %ELF_end>PE32_text ; SizeOfRawData 70 01 00 00 ; PointerToRawData 00 00 00 00 ; PointerToRelocations 00 00 00 00 ; PointerToLinenumbers 00 00 ; NumberOfRelocations 00 00 ; NumberOfLinenumbers 00 00 00 00 ; 'Characteristics' # [0x170] :PE32_text # efi_main(void *image_handle, struct efi_system_table *system) :_start # Save non-volatile registers 55 ; push_rbp 53 ; push_rbx 57 ; push_rdi 56 ; push_rsi 4154 ; push_r12 4155 ; push_r13 4156 ; push_r14 4157 ; push_r15 4889E5 ; mov_rbp,rsp # save stack pointer 4989CC ; mov_r12,rcx # save image_handle 4C8B72 60 ; mov_r14,[rdx+BYTE] !96 # save system->boot # Open Loaded Image protocol 4D89E1 ; mov_r9,r12 # arg4 = image_handle 488D15 %LOADED_IMAGE_PROTOCOL ; lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # guid = &LOADED_IMAGE_PROTOCOL 4C89E1 ; mov_rcx,r12 # arg1 = image_handle E8 %open_protocol ; call %open_protocol # open protocol 4889C7 ; mov_rdi,rax # save image # Get root file system 4D89E1 ; mov_r9,r12 # arg4 = image_handle 488D15 %SIMPLE_FS_PROTOCOL ; lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # guid = &SIMPLE_FS_PROTOCOL 488B4F 18 ; mov_rcx,[rdi+BYTE] !24 # arg1 = root_device = image->device 48890D %root_device ; mov_[rip+DWORD],rcx %root_device # save root_device E8 %open_protocol ; call %open_protocol # open protocol 4889C1 ; mov_rcx,rax # get rootfs # Get root directory 488D15 %rootdir ; lea_rdx,[rip+DWORD] %rootdir # arg2 = &rootdir 4883EC 28 ; sub_rsp, !40 # allocate shadow stack space for UEFI function FF51 08 ; call_[rcx+BYTE] !8 # rootfs->open_volume(rootfs, &rootdir) 4883C4 28 ; add_rsp, !40 # deallocate stack # Push command line arguments onto stack 488B5F 38 ; mov_rbx,[rdi+BYTE] !56 # options = image->load_options 4889DA ; mov_rdx,rbx # save beginning of load_options 48035F 30 ; add_rbx,[rdi+BYTE] !48 # go to the end of load_options 6A 00 ; push !0 # Save end of arguments (NULL) onto stack :loop_options 4839D3 ; cmp_rbx,rdx # Check if we are done 74 !loop_options_done ; je !loop_options_done # We are done 4883EB 02 ; sub_rbx, !2 # --options 8A03 ; mov_al,[rbx] # *options 3C 20 ; cmp_al, !0x20 # if *options != ' ' 75 !loop_options ; jne !loop_options # then continue looping C603 00 ; mov_[rbx], !0 # zero it 4883C3 02 ; add_rbx, !2 # ++options 53 ; push_rbx # push another argument onto stack EB !loop_options ; jmp !loop_options # next argument :loop_options_done 4158 ; pop_r8 # get output file 4D85C0 ; test_r8,r8 # if no output file 0F84 %exit_early ; je32 %exit_early # then exit # Open file for writing 52 ; push_rdx # allocate stack for fout 4889E2 ; mov_rdx,rsp # arg2 = &fout 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 # align stack 6A 00 ; push !0 # arg5 = 0 6A 07 ; push !7 # to get 0x8000000000000003 we set the rightmost 3 bits 4159 ; pop_r9 # and then do right rotation by 1 49D1C9 ; ror_r9 # arg4 = EFI_FILE_MODE_CREATE| EFI_FILE_MODE_WRITE | EFI_FILE_MODE_READ 488B0D %rootdir ; mov_rcx,[rip+DWORD] %rootdir # arg1 = rootdir 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function FF51 08 ; call_[rcx+BYTE] !8 # rootdir->open() 488B6424 38 ; mov_rsp,[rsp+BYTE] !56 # deallocate stack 415F ; pop_r15 # get fout 48C7C2 00001000 ; mov_rdx, %0x100000 # Allocate 1MB E8 %allocate_pool ; call %allocate_pool # Get memory pool 4889C3 ; mov_rbx,rax # Save it :core 4158 ; pop_r8 # Get the actual input name 4983F8 00 ; cmp_r8, !0 # Check for null string 74 !done ; je !done # We are done if null string E8 %open_file ; call %open_file # Open file as read only 85C0 ; test_eax,eax # check if successfully opened 75 !core ; jne !core # Else go to another file 4989F5 ; mov_r13,rsi # Protect fin :keep 48C7C2 00001000 ; mov_rdx, %0x100000 # set the size of chars we want E8 %read ; call %read # read them 50 ; push_rax # Protect the number of bytes read 4889C2 ; mov_rdx,rax # number of bytes to write E8 %write ; call %write # write them 58 ; pop_rax # Get bytes read 483D 00001000 ; cmp_rax, %0x100000 # Check if buffer was fully used 74 !keep ; je !keep # Keep looping if it was full 4C89E9 ; mov_rcx,r13 # fin E8 %close_file ; call %close_file # close file EB !core ; jmp !core # Move to next file :done 4C89F9 ; mov_rcx,r15 # Get output file E8 %close_file ; call %close_file # close it 4889D9 ; mov_rcx,rbx # Get buffer E8 %free_pool ; call %free_pool # release it :exit_early 488B0D %rootdir ; mov_rcx,[rip+DWORD] %rootdir # Get rootdir E8 %close_file ; call %close_file # close it 4D89E0 ; mov_r8,r12 # arg3 = image_handle 488D15 %SIMPLE_FS_PROTOCOL ; lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID 488B0D %root_device ; mov_rcx,[rip+DWORD] %root_device # arg1 = root_device E8 %close_protocol ; call %close_protocol # close protocol 4D89E0 ; mov_r8,r12 # arg3 = image_handle 488D15 %LOADED_IMAGE_PROTOCOL ; lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # EFI_LOADED_IMAGE_PROTOCOL_GUID 4C89E1 ; mov_rcx,r12 # arg1 = image_handle E8 %close_protocol ; call %close_protocol # close protocol # Restore non-volatile registers 4889EC ; mov_rsp,rbp 415F ; pop_r15 415E ; pop_r14 415D ; pop_r13 415C ; pop_r12 5E ; pop_rsi 5F ; pop_rdi 5B ; pop_rbx 5D ; pop_rbp C3 ; ret # return to UEFI # r8: input file name # returns input file handle in rsi, status in rax :open_file # Open file for reading 52 ; push_rdx # allocate stack for fin 4889E2 ; mov_rdx,rsp # arg2 = &fin 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 # align stack 6A 01 ; push !1 # arg5 = EFI_FILE_READ_ONLY 6A 01 ; push !1 # prepare to set arg4 to EFI_FILE_MODE_READ 4159 ; pop_r9 # arg4 = EFI_FILE_MODE_READ 488B0D %rootdir ; mov_rcx,[rip+DWORD] %rootdir # arg1 = rootdir 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function FF51 08 ; call_[rcx+BYTE] !8 # rootdir->open() 488B6424 38 ; mov_rsp,[rsp+BYTE] !56 # deallocate stack 5E ; pop_rsi # get fin C3 ; ret # rcx: file handle :close_file 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 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function FF51 10 ; call_[rcx+BYTE] !16 # file_handle->close(file_handle) 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack C3 ; ret # rcx: handle # rdx: &guid # r9: agent_handle # returns interface :open_protocol 50 ; push_rax # allocate stack for interface 4989E0 ; mov_r8,rsp # arg3 = &interface 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 6A 01 ; push !1 # arg6 = EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL 6A 00 ; push !0 # arg5 = NULL 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function 41FF96 18010000 ; call_[r14+DWORD] %280 # system->boot->open_protocol(handle, &guid, &interface, agent_handle, 0, EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL) 488B6424 38 ; mov_rsp,[rsp+BYTE] !56 # deallocate stack 58 ; pop_rax # get interface C3 ; ret # rcx: handle # rdx: &guid # r8: agent_handle :close_protocol 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 4D31C9 ; xor_r9,r9 # arg4 = NULL 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function 41FF96 20010000 ; call_[r14+DWORD] %288 # system->boot->close_protocol(handle, &guid, agent_handle, 0) 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack C3 ; ret # rdx: number of bytes to allocate # r14: system->boot # returns pointer in rax :allocate_pool 52 ; push_rdx # allocate stack for pool pointer 4989E0 ; mov_r8,rsp # arg3 = &pool 6A 02 ; push !2 59 ; pop_rcx # arg1 = EFI_LOADER_DATA 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 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function 41FF56 40 ; call_[r14+BYTE] !64 # system->boot->allocate_pool(EFI_LOADER_DATA, 2048, &pool) 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack 58 ; pop_rax # get pool C3 ; ret # rcx: memory pool # r14: system->boot :free_pool 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 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function 41FF56 48 ; call_[r14+BYTE] !72 # system->boot->free_pool(pool) 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack C3 ; ret # rdx: number of bytes to read # rbx: buffer # r13: input file handle # returns number of bytes read in rax :read 4C89E9 ; mov_rcx,r13 # arg1 = fin 52 ; push_rdx # set size 4889E2 ; mov_rdx,rsp # arg2 = &size 4989D8 ; mov_r8,rbx # arg3 = buffer 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 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function FF51 20 ; call_[rcx+BYTE] !32 # fin->read() 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack 58 ; pop_rax # save size to rax C3 ; ret # rdx: number of bytes to write # rbx: buffer # r14: output file handle # returns number of bytes written in rax :write 4C89F9 ; mov_rcx,r15 # arg1 = fout 52 ; push_rdx # set size 4889E2 ; mov_rdx,rsp # arg2 = &size 4989D8 ; mov_r8,rbx # arg3 = buffer 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 4883EC 20 ; sub_rsp, !32 # allocate shadow stack space for UEFI function FF51 28 ; call_[rcx+BYTE] !40 # fin->write() 488B6424 28 ; mov_rsp,[rsp+BYTE] !40 # deallocate stack 58 ; pop_rax # save size to rax C3 ; ret # Protocol GUIDs :LOADED_IMAGE_PROTOCOL 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 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 :rootdir 00000000 00000000 :root_device 00000000 00000000 :ELF_end