# SPDX-FileCopyrightText: 2022 Andrius Štikonas # SPDX-FileCopyrightText: 2017 Jeremiah Orians # # SPDX-License-Identifier: GPL-3.0-or-later DEFINE add_rbx, 4883C3 DEFINE add_rsp, 4883C4 DEFINE add_r13, 4981C5 DEFINE add_rax,rcx 4801C8 DEFINE add_rax,r14 4C01F0 DEFINE add_rbx,[rdi+BYTE] 48035F DEFINE call E8 DEFINE call_[rcx+BYTE] FF51 DEFINE call_[r14+BYTE] 41FF56 DEFINE call_[r14+DWORD] 41FF96 DEFINE cmp_al, 3C DEFINE cmp_rax, 483D DEFINE cmp_r15, 4981FF DEFINE cmp_rbx,rdx 4839D3 DEFINE je 0F84 DEFINE je8 74 DEFINE jl 0F8C DEFINE jmp E9 DEFINE jmp8 EB DEFINE jne 0F85 DEFINE jne8 75 DEFINE lea_rdx,[rip+DWORD] 488D15 DEFINE mov_dh, B6 DEFINE mov_rax, 48C7C0 DEFINE mov_rdx, 48C7C2 DEFINE mov_r13, 49C7C5 DEFINE mov_r14, 49C7C6 DEFINE mov_r15, 49C7C7 DEFINE mov_rbp,rsp 4889E5 DEFINE mov_rcx,rbx 4889D9 DEFINE mov_rcx,rdi 4889F9 DEFINE mov_rcx,rsi 4889F1 DEFINE mov_rcx,r8 4C89C1 DEFINE mov_rcx,r9 4C89C9 DEFINE mov_rcx,r13 4C89E9 DEFINE mov_rdx,rbx 4889DA DEFINE mov_rdx,rsp 4889E2 DEFINE mov_rsp,rbp 4889EC DEFINE mov_r8,rsp 4989E0 DEFINE mov_r8,r15 4D89F8 DEFINE mov_r9,r15 4D89F9 DEFINE mov_r13,rcx 4989CD DEFINE mov_r14,rax 4989C6 DEFINE mov_r15,rcx 4989CF DEFINE mov_al,[rbx] 8A03 DEFINE mov_rax,[rax] 488B00 DEFINE mov_[rbx], C603 DEFINE mov_rbx,[rdi+BYTE] 488B5F DEFINE mov_rcx,[rdi+BYTE] 488B4F DEFINE mov_rcx,[rsp+BYTE] 488B4C24 DEFINE mov_rdi,[rsp+BYTE] 488B7C24 DEFINE mov_r14,[rdx+BYTE] 4C8B72 DEFINE mov_[rax],r13 4C8928 DEFINE not_r15 49F7D7 DEFINE pop_rax 58 DEFINE pop_rbx 5B DEFINE pop_rcx 59 DEFINE pop_rdi 5F DEFINE pop_rsi 5E DEFINE pop_r8 4158 DEFINE pop_r9 4159 DEFINE pop_r13 415D DEFINE pop_r14 415E DEFINE pop_r15 415F DEFINE push 6A DEFINE push_rax 50 DEFINE push_rbx 53 DEFINE push_rdx 52 DEFINE push_rsi 56 DEFINE push_r13 4155 DEFINE push_r14 4156 DEFINE push_r15 4157 DEFINE ret C3 DEFINE ror_r9 49D1C9 DEFINE shl_rax, 48C1E0 DEFINE shl_r14, 49C1E6 DEFINE sub_rax, 4883E8 DEFINE sub_rbx, 4883EB DEFINE sub_rsp, 4883EC DEFINE sub_rax,r13 4C29E8 DEFINE test_esi,esi 85F6 DEFINE xor_edx,edx 31D2 DEFINE xor_esi,esi 31F6 DEFINE xor_r9,r9 4D31C9 # efi_main(void *image_handle, struct efi_system_table *system) :_start mov_rbp,rsp # save stack pointer mov_r15,rcx # save image_handle mov_r14,[rdx+BYTE] !96 # system->boot # Open Loaded Image protocol mov_r9,r15 # arg4 = image_handle lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # guid = &LOADED_IMAGE_PROTOCOL mov_rcx,r9 # arg1 = image_handle push_rax # allocate stack for image mov_r8,rsp # arg3 = &image push !1 # arg6 = EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL push !0 # arg5 = NULL sub_rsp, !32 # allocate shadow stack space for UEFI function call_[r14+DWORD] %280 # system->boot->open_protocol(image_handle, &guid, &image, image_handle, 0, EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL) mov_rdi,[rsp+BYTE] !48 # save image # Get root file system mov_r9,r15 # arg4 = image_handle lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # guid = &SIMPLE_FS_PROTOCOL mov_rcx,[rdi+BYTE] !24 # arg1 = root_device = image->device mov_r13,rcx # save root_device push_rax # allocate stack for rootfs mov_r8,rsp # arg3 = &rootfs push !1 # arg6 = EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL push !0 # arg5 = NULL sub_rsp, !32 # allocate shadow stack space for UEFI function call_[r14+DWORD] %280 # system->boot->open_protocol(root_device, &guid, &rootfs, image_handle, 0, EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL) mov_rcx,[rsp+BYTE] !48 # get rootfs # Get root directory push_rax # allocate stack for rootdir mov_rdx,rsp # arg2 = &rootdir push_rax # allocate shadow stack space for UEFI function push_rax # allocate shadow stack space for UEFI function call_[rcx+BYTE] !8 # rootfs->open_volume(rootfs, &rootdir) pop_rax # deallocate stack pop_rax # deallocate stack pop_rsi # get rootdir # Push command line arguments onto stack mov_rbx,[rdi+BYTE] !56 # options = image->load_options mov_rdx,rbx # save beginning of load_options add_rbx,[rdi+BYTE] !48 # go to the end of load_options push !0 # Save end of arguments (NULL) onto stack :loop_options cmp_rbx,rdx # Check if we are done je8 !loop_options_done # We are done sub_rbx, !2 # --options mov_al,[rbx] # *options cmp_al, !0x20 # if *options != ' ' jne8 !loop_options # then continue looping mov_[rbx], !0 # zero it add_rbx, !2 # ++options push_rbx # push another argument onto stack jmp8 !loop_options # next argument :loop_options_done # Open file for reading pop_r8 # arg3 = in push_rdx # allocate stack for fin mov_rdx,rsp # arg2 = &fin push !1 # arg5 = EFI_FILE_READ_ONLY push !1 # prepare to set arg4 to EFI_FILE_MODE_READ pop_r9 # arg4 = EFI_FILE_MODE_READ mov_rcx,rsi # arg1 = rootdir sub_rsp, !32 # allocate shadow stack space for UEFI function call_[rcx+BYTE] !8 # rootdir->open() add_rsp, !40 # deallocate stack pop_rdi # get fin # Open file for writing pop_r8 # arg3 = out push_rdx # allocate stack for fout mov_rdx,rsp # arg2 = &fout push !0 # arg5 = 0 push !7 # to get 0x8000000000000003 we set the rightmost 3 bits pop_r9 # and then do right rotation by 1 ror_r9 # arg4 = EFI_FILE_MODE_CREATE| EFI_FILE_MODE_WRITE | EFI_FILE_MODE_READ mov_rcx,rsi # arg1 = rootdir sub_rsp, !32 # allocate shadow stack space for UEFI function call_[rcx+BYTE] !8 # rootdir->open() add_rsp, !40 # deallocate stack pop_rbx # get fout # Save variables that are needed for cleanup push_r13 # save root_device push_r14 # save system->boot push_r15 # save image_handle push_rsi # save rootdir # Allocate pool for single-character label table # pointer to table will be stored at the top of the stack push_rdx # allocate stack for table mov_r8,rsp # arg3 = &table xor_edx,edx # zero rdx mov_dh, !0x8 # arg2 = 256 * 8 = 2048 = 0x800 push !2 pop_rcx # arg1 = EFI_LOADER_DATA sub_rsp, !24 # allocate shadow stack space for UEFI function call_[r14+BYTE] !64 # system->boot->allocate_pool(EFI_LOADER_DATA, 2048, &table) add_rsp, !24 # deallocate stack mov_r15, %-1 # Our flag for byte processing mov_r14, %0 # temp storage for the sum mov_r13, %0 # Our starting IP call %First_pass # Process it # rewind input file mov_rcx,rdi # Using our input file xor_edx,edx # Offset Zero push_rax # allocate shadow stack space for UEFI function push_rax # allocate shadow stack space for UEFI function call_[rcx+BYTE] !56 # fin->set_position(fin, 0) pop_rax # deallocate stack pop_rax # deallocate stack mov_r15, %-1 # Our flag for byte processing mov_r14, %0 # temp storage for the sum mov_r13, %0 # Our starting IP call %Second_pass # Process it jmp %Done :First_pass call %Read_byte # Deal with EOF cmp_rax, %-4 je %First_pass_done # Check for : cmp_rax, %0x3a jne %First_pass_0 # Deal with label call %StoreLabel :First_pass_0 # Check for % cmp_rax, %0x25 je %First_pass_pointer # Deal with everything else call %hex # Process our char # Deal with EOF cmp_rax, %-4 je %First_pass_done # deal with -1 values cmp_rax, %0 jl %First_pass # deal with toggle cmp_r15, %0 je %First_pass_1 add_r13, %1 # Increment IP :First_pass_1 not_r15 jmp %First_pass :First_pass_pointer # Deal with Pointer to label call %Read_byte # Drop the char add_r13, %4 # Increment IP jmp %First_pass # Loop again :First_pass_done ret :hex # deal with EOF cmp_rax, %-4 je %EOF # deal with line comments starting with # cmp_rax, %0x23 je %ascii_comment # deal with line comments starting with ; cmp_rax, %0x3b je %ascii_comment # deal all ascii less than 0 cmp_rax, %0x30 jl %ascii_other # deal with 0-9 cmp_rax, %0x3a jl %ascii_num # deal with all ascii less than A cmp_rax, %0x41 jl %ascii_other # deal with A-F cmp_rax, %0x47 jl %ascii_high # deal with all ascii less than a cmp_rax, %0x61 jl %ascii_other # deal with a-f cmp_rax, %0x67 jl %ascii_low # The rest that remains needs to be ignored jmp %ascii_other :Second_pass call %Read_byte # Deal with EOF cmp_rax, %-4 je %Second_pass_done # Simply drop the label cmp_rax, %0x3a jne %Second_pass_0 call %Read_byte jmp %Second_pass :Second_pass_0 # Deal with % pointer cmp_rax, %0x25 jne %Second_pass_1 call %StorePointer jmp %Second_pass :Second_pass_1 # Deal with everything else call %hex # Process our char # Deal with EOF cmp_rax, %-4 je %Second_pass_done # deal with -1 values cmp_rax, %0 jl %Second_pass # deal with toggle cmp_r15, %0 je %print # process first byte of pair mov_r14,rax mov_r15, %0 jmp %Second_pass :Second_pass_done :EOF ret :ascii_num sub_rax, !0x30 ret :ascii_low sub_rax, !0x57 ret :ascii_high sub_rax, !0x37 ret :ascii_other mov_rax, %-1 ret :ascii_comment call %Read_byte cmp_rax, %0xd je %ascii_comment_cr cmp_rax, %0xa jne %ascii_comment :ascii_comment_cr mov_rax, %-1 ret # process second byte of pair :print # update the sum and store in output shl_r14, !4 add_rax,r14 # flip the toggle not_r15 # R15 = -1 mov_rdx, %1 # set the size of chars we want call %print_chars add_r13, %1 # Increment IP jmp %Second_pass :Read_byte mov_rcx,rdi # 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_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 pop_rax # save input to rax pop_rsi # save size to rsi # If the file ended (0 bytes read) return EOF test_esi,esi # if size = 0 jne8 !Read_byte_1 mov_rax, %-4 # Put EOF in rax :Read_byte_1 ret # return # Writes bytes stored in rax :print_chars mov_rcx,rbx # arg1 = fout push_rdx # set size mov_rdx,rsp # arg2 = &size push_rax # allocate stack mov_r8,rsp # arg3 = &output 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] !40 # fout->write() add_rsp, !40 # deallocate stack ret # return :Get_table_target call %Read_byte # Get single char label shl_rax, !3 # Each label in table takes 8 bytes to store mov_rcx,[rsp+BYTE] !24 # Get table add_rax,rcx # Calculate offset ret :StoreLabel call %Get_table_target mov_[rax],r13 # Write out pointer to table ret :StorePointer add_r13, %4 # Increment IP call %Get_table_target # Get address of pointer mov_rax,[rax] # Get pointer sub_rax,r13 # target - ip mov_rdx, %4 # set the size of chars we want call %print_chars ret :Done pop_rcx # restore table pop_rsi # restore rootdir pop_r15 # restore image_handle pop_r14 # restore system->boot pop_r13 # restore root_device # Free pool # arg1 = table push_rax # allocate shadow stack space for UEFI function call_[r14+BYTE] !72 # system->boot->free_pool(table) mov_rcx,rdi # arg1 = fin call_[rcx+BYTE] !16 # fin->close() mov_rcx,rbx # arg1 = fout call_[rcx+BYTE] !16 # fout->close() mov_rcx,rsi # arg1 = rootdir call_[rcx+BYTE] !16 # rootdir->close() mov_r8,r15 # arg3 = image_handle lea_rdx,[rip+DWORD] %SIMPLE_FS_PROTOCOL # guid = &SIMPLE_FS_PROTOCOL mov_rcx,r13 # arg1 = root_device xor_r9,r9 # arg4 = NULL sub_rsp, !32 # allocate shadow stack space for UEFI function call_[r14+DWORD] %288 # system->boot->close_protocol(root_device, &guid, image_handle, 0) mov_r8,r15 # arg3 = image_handle lea_rdx,[rip+DWORD] %LOADED_IMAGE_PROTOCOL # guid = &LOADED_IMAGE_PROTOCOL mov_rcx,r8 # arg1 = image_handle xor_r9,r9 # arg4 = NULL call_[r14+DWORD] %288 # system->boot->close_protocol(image_handle, &guid, image_handle, 0) mov_rsp,rbp # restore stack ret # return to UEFI # Protocol GUIDs :LOADED_IMAGE_PROTOCOL %0x5b1b31a1 @0x9562 @0x11d2 !0x8e !0x3f !0 !0xa0 !0xc9 !0x69 !0x72 !0x3b :SIMPLE_FS_PROTOCOL %0x0964e5b22 @0x6459 @0x11d2 !0x8e !0x39 !0 !0xa0 !0xc9 !0x69 !0x72 !0x3b :PE32_end