andrius
/
stage0-uefi
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

hex0.S: initial working version, still needs some optimizations.

This commit is contained in:
Andrius Štikonas 2022-07-15 22:37:45 +01:00
parent 159d30e184
commit 9895b0da06
2 changed files with 161 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
Development/hex0.c
View File

@ -64,10 +64,9 @@ next_byte:
}
/* Check if it's a comment */
if (c == '#' || c == ';') {
goto loop;
if (c != '#' && c != ';') {
goto not_comment;
}
goto not_comment;
loop:
fin->read(fin, &size, &c);
@ -78,7 +77,7 @@ next_byte:
/* Check if read byte is the end of the comment (i.e. a newline character),
* in that case we continue processing */
if (c == '\n' || c == '\r') {
if (c == '\n') {
goto next_byte;
}
goto loop;
@ -114,8 +113,8 @@ not_comment:
goto next_byte;
terminate:
rootdir->close(fin);
rootdir->close(fout);
fin->close(fin);
fout->close(fout);
return 0;
}

168
amd64/Development/hex0.S
View File

@ -1,9 +1,10 @@
# SPDX-FileCopyrightText: 2022 Andrius Štikonas <andrius@stikonas.eu>
# SPDX-FileCopyrightText: 2017 Jeremiah Orians <jeremiah@pdp10.guru>
#
# SPDX-License-Identifier: GPL-3.0-or-later
# Usage hex0 file.hex0 file
# Does not validate the arguments
# Does not validate the arguments or check for success
# Calling convention:
# First four arguments are passed via registers rcx, rdx, r8, r9 (if they fit in 64-bits)
@ -77,43 +78,186 @@ loop_options2: # Skip argv[1]
mov rcx, [rsp+64] # get rootfs
add rsp, 72 # deallocate stacks
sub rsp, 32 # allocate stack
sub rsp, 24 # allocate stack
lea rdx, [RootDir] # arg2 = &rootdir
call [rcx+8] # rootfs->open_volume(rootfs, &rootdir)
# Open file for writing
add rsp, 32 # deallocate stack
add rsp, 24 # deallocate stack
mov rcx, [RootDir] # arg1 = rootdir
pop r8 # arg3 = out
sub rsp, 48 # allocate stack
lea rdx, [rsp+40] # arg2 = &fout
sub rsp, 40 # allocate stack
lea rdx, [fout] # arg2 = &fout
mov r9, 0x8000000000000003 # arg4 = EFI_FILE_MODE_CREATE| EFI_FILE_MODE_WRITE | EFI_FILE_MODE_READ
mov qword ptr [rsp+32], 0 # arg5 = 0
call [rcx+8] # rootdir->open()
# Open file for reading
mov r12, [rsp+40] # save fout
add rsp, 48 # deallocate stack
add rsp, 40 # deallocate stack
mov rcx, [RootDir] # arg1 = rootdir
pop r8 # arg3 = in
sub rsp, 48 # allocate stack
lea rdx, [rsp+40] # arg2 = &fin
sub rsp, 40 # allocate stack
lea rdx, [fin] # arg2 = &fin
mov r9, 1 # arg4 = EFI_FILE_MODE_READ
mov qword ptr [rsp+32], 1 # arg5 = EFI_FILE_READ_ONLY
call [rcx+8] # rootdir->open()
add rsp, 40 # deallocate stack
mov r13, [rsp+40] # save fin
add rsp, 48 # deallocate stack
Done:
# Our flag for byte processing
mov r15, -1
# temp storage for the sum
mov r14, 0
loop:
# Read a byte
call read_byte
# process byte
call hex
# Deal with -1 values
cmp rax, 0
jl loop
# deal with toggle
cmp r15, 0
jge print
# process first byte of pair
mov r14, rax
mov r15, 0
jmp loop
# process second byte of pair
print:
# update the sum and store in output
shl r14, 4
add rax, r14
mov [output], al
# flip the toggle
mov r15, -1
call write_byte
jmp loop
hex:
# Purge Comment Lines (#)
cmp rax, 35
je purge_comment
# Purge Comment Lines (;)
cmp rax, 59
je purge_comment
# deal all ascii less than 0
cmp rax, 48
jl ascii_other
# deal with 0-9
cmp rax, 58
jl ascii_num
# deal with all ascii less than A
cmp rax, 65
jl ascii_other
# deal with A-F
cmp rax, 71
jl ascii_high
# deal with all ascii less than a
cmp rax, 97
jl ascii_other
# deal with a-f
cmp rax, 103
jl ascii_low
# The rest that remains needs to be ignored
jmp ascii_other
purge_comment:
# Read a byte
call read_byte
# Loop if not LF (works for CR/LF and LF/CR endings too)
cmp rax, 10
jne purge_comment
# Otherwise return -1
mov rax, -1
ret
ascii_num:
sub rax, 48
ret
ascii_low:
sub rax, 87
ret
ascii_high:
sub rax, 55
ret
ascii_other:
mov rax, -1
ret
terminate:
sub rsp, 32 # allocate stack
mov rcx, [fin] # arg1 = fin
call [rcx+16] # fin->close()
mov rcx, [fout] # arg1 = fout
call [rcx+16] # fout->close()
mov rcx, [ImageHandle] # arg1 = ImageHandle
mov rdx, 0 # exit code
mov rax, [SystemBoot]
call [rax+216] # system->boot->exit(ImageHandle, 0)
add rsp, 32 # deallocate stack
read_byte:
sub rsp, 32 # allocate stack
mov qword ptr [size], 1 # size = 1
mov rcx, [fin] # arg1 = fin
lea rdx, [size] # arg2 = &size
lea r8, [input] # arg3 = &input
call [rcx+32] # fin->read()
add rsp, 32 # deallocate stack
# If the file ended (0 bytes read) terminate
cmp qword ptr [size], 0 # if size == 0
je terminate # then we are done
movzx rax, byte ptr [input] # save character to rax
ret # return
write_byte:
sub rsp, 32 # allocate stack
mov qword ptr [size], 1 # size = 1
mov rcx, [fout] # arg1 = fout
lea rdx, [size] # arg2 = &size
lea r8, [output] # arg3 = &output
call [rcx+40] # fout->write()
add rsp, 32 # deallocate stack
ret # return
.data
ImageHandle: .quad 0
SystemBoot: .quad 0
RootDir: .quad 0
fin: .quad 0
fout: .quad 0
size: .quad 0
input: .byte 0
output: .quad 0
# Protocol GUIDs
LOADED_IMAGE_PROTOCOL: