Port hex0.S optimizations from stage0-posix.
This commit is contained in:
parent
85e3b0caef
commit
7f27324a5b
|
|
@ -9,12 +9,15 @@
|
|||
# Calling convention:
|
||||
# First four arguments are passed via registers rcx, rdx, r8, r9 (if they fit in 64-bits)
|
||||
# but we need to leave stack space
|
||||
# rax, rcx, rdx, r8, r9, r10 and r11 are volatile and can be changed by called function
|
||||
|
||||
# Registers:
|
||||
# r12 in/fin: input file name, later reused for handle
|
||||
# r13 out/fout: output file name, later reused for handle
|
||||
# r14 system->boot->open_protocol from UEFI, later reused for hex0 algorithm, later reused for rootdir
|
||||
# r15 image_handle from UEFI, later reused for hex0 algorithm
|
||||
# r14 system->boot->open_protocol from UEFI, later reused for rootdir
|
||||
# r15 image_handle from UEFI
|
||||
|
||||
# hex0 algorithm mostly follows stage0-posix version but uses rdi instead of rbp
|
||||
|
||||
.global _start
|
||||
.text
|
||||
|
|
@ -118,10 +121,10 @@ loop_options2: # Skip argv[1]
|
|||
|
||||
# Our flag for byte processing
|
||||
push -1
|
||||
pop r15 # r15 = -1
|
||||
pop rbx # rbx = -1
|
||||
|
||||
# temp storage for the sum
|
||||
xor r14d, r14d # r14 = 0
|
||||
xor edi, edi # edi = 0
|
||||
|
||||
loop:
|
||||
# Read a byte
|
||||
|
|
@ -131,27 +134,26 @@ loop:
|
|||
call hex
|
||||
|
||||
# Deal with -1 values
|
||||
test rax, rax
|
||||
test eax, eax
|
||||
jl loop
|
||||
|
||||
# deal with toggle
|
||||
test r15, r15
|
||||
test ebx, ebx # jump if ebx >= 0
|
||||
jge print
|
||||
|
||||
# process first byte of pair
|
||||
mov r14, rax
|
||||
xor r15d, r15d # r15 = 0
|
||||
mov edi, eax
|
||||
xor ebx, ebx # ebx = 0
|
||||
jmp loop
|
||||
|
||||
# process second byte of pair
|
||||
print:
|
||||
# update the sum and store in output
|
||||
shl r14, 4
|
||||
add rax, r14
|
||||
shl edi, 4
|
||||
add eax, edi
|
||||
|
||||
# flip the toggle
|
||||
push -1
|
||||
pop r15 # r15 = -1
|
||||
dec ebx # rbx = -1
|
||||
|
||||
call write_byte
|
||||
|
||||
|
|
@ -159,35 +161,35 @@ print:
|
|||
|
||||
hex:
|
||||
# Purge Comment Lines (#)
|
||||
cmp rax, 35
|
||||
cmp al, 35
|
||||
je purge_comment
|
||||
|
||||
# Purge Comment Lines (;)
|
||||
cmp rax, 59
|
||||
cmp al, 59
|
||||
je purge_comment
|
||||
|
||||
# deal all ascii less than 0
|
||||
cmp rax, 48
|
||||
cmp al, 48
|
||||
jl ascii_other
|
||||
|
||||
# deal with 0-9
|
||||
cmp rax, 58
|
||||
cmp al, 58
|
||||
jl ascii_num
|
||||
|
||||
# deal with all ascii less than A
|
||||
cmp rax, 65
|
||||
cmp al, 65
|
||||
jl ascii_other
|
||||
|
||||
# deal with A-F
|
||||
cmp rax, 71
|
||||
cmp al, 71
|
||||
jl ascii_high
|
||||
|
||||
# deal with all ascii less than a
|
||||
cmp rax, 97
|
||||
cmp al, 97
|
||||
jl ascii_other
|
||||
|
||||
# deal with a-f
|
||||
cmp rax, 103
|
||||
cmp al, 103
|
||||
jl ascii_low
|
||||
|
||||
# The rest that remains needs to be ignored
|
||||
|
|
@ -198,62 +200,26 @@ purge_comment:
|
|||
call read_byte
|
||||
|
||||
# Loop if not LF (works for CR/LF and LF/CR endings too)
|
||||
cmp rax, 10
|
||||
cmp al, 10
|
||||
jne purge_comment
|
||||
|
||||
# Otherwise return -1
|
||||
push -1
|
||||
pop rax # rax = -1
|
||||
ret
|
||||
|
||||
ascii_num:
|
||||
sub rax, 48
|
||||
ret
|
||||
|
||||
ascii_low:
|
||||
sub rax, 87
|
||||
ret
|
||||
|
||||
ascii_high:
|
||||
sub rax, 55
|
||||
ret
|
||||
|
||||
ascii_other:
|
||||
push -1
|
||||
pop rax # rax = -1
|
||||
pop rax # return = -1
|
||||
ret
|
||||
|
||||
terminate:
|
||||
push rbx # allocate stack
|
||||
mov rcx, r12 # arg1 = fin
|
||||
call [rcx+16] # fin->close()
|
||||
mov rcx, r13 # arg1 = fin
|
||||
call [rcx+16] # fout->close()
|
||||
abort: # used for debugging only
|
||||
mov rsp, rbp # restore stack
|
||||
ret # return to UEFI
|
||||
ascii_num:
|
||||
sub al, 48
|
||||
ret
|
||||
|
||||
read_byte:
|
||||
mov rcx, r12 # arg1 = fin
|
||||
push 1 # size = 1
|
||||
mov rdx, rsp # arg2 = &size
|
||||
push rbx # 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+32] # fin->read()
|
||||
pop rax # deallocate stack
|
||||
pop rax # deallocate stack
|
||||
pop rax # deallocate stack
|
||||
pop rax # save input to rax
|
||||
pop rbx # save size to rbx
|
||||
ascii_low:
|
||||
sub al, 32 # convert to uppercase
|
||||
|
||||
# If the file ended (0 bytes read) terminate
|
||||
test rbx, rbx # if size == 0
|
||||
je terminate # then we are done
|
||||
|
||||
ret # return
|
||||
ascii_high:
|
||||
sub al, 55
|
||||
ret
|
||||
|
||||
# Writes byte stored in al
|
||||
write_byte:
|
||||
|
|
@ -269,6 +235,39 @@ write_byte:
|
|||
add rsp, 40 # deallocate stack
|
||||
|
||||
ret # return
|
||||
|
||||
read_byte:
|
||||
mov rcx, r12 # arg1 = fin
|
||||
push 1 # size = 1
|
||||
mov rdx, rsp # arg2 = &size
|
||||
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+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) terminate
|
||||
test rsi, rsi # if size == 0
|
||||
je terminate # then we are done
|
||||
|
||||
ret # return
|
||||
|
||||
terminate:
|
||||
push rbx # allocate stack
|
||||
mov rcx, r12 # arg1 = fin
|
||||
call [rcx+16] # fin->close()
|
||||
mov rcx, r13 # arg1 = fin
|
||||
call [rcx+16] # fout->close()
|
||||
abort: # used for debugging only
|
||||
mov rsp, rbp # restore stack
|
||||
ret # return to UEFI
|
||||
|
||||
.data
|
||||
|
||||
# Protocol GUIDs
|
||||
|
|
|
|||
Loading…
Reference in New Issue