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JUMP command

This commit is contained in:
Sarah Jamie Lewis 2021-11-12 22:03:26 -08:00
parent 23c5195365
commit 9a1ce420ed
4 changed files with 136 additions and 9 deletions
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55
kernel.asm
View File

@ -7,6 +7,7 @@
$0000000 ; RAX
$0000000 ; R2 - Temp Scratch
$0000000 ; R3 - Temp Scratch
label ARG1
$0000000 ; R4 - ARG 1
$0000000 ; R5 - ARG 2
$0000000 ; R6 - ARG 3
@ -27,6 +28,8 @@
@ $4B0C0:
hlt
import display.asm ; setpos
import charset.asm ; charset + hex strings
import strings.asm ; draw_char, draw_string
@ -47,6 +50,7 @@ data image boo_os_small.png booos-small.png
data image wallpaper.png wallpaper.png
data ascii quit_label QUIT
data ascii diss_label JUMP
data buffer command_line_input 64
@ -57,20 +61,32 @@ meta
; strcmp compares 2 strings in a byte-by-byte manner, incrementing ptrs as it goes. Returns 1 if both bytes
; point to 0. Returns 0 (fail) if it encounters 2 different bytes
; clobbers $1 $2 $4 $5
; clobbers $1 $2 $3 $4 $5
label strcmp:
loadi $3 $0
label strcmp_loop:
rload $4 $1
rload $5 $2
jeq +3 ; if either of these differ then return 0 to indicate these strings don't match
loadi $1 0
ret
loadi $2 0
jneq +3 ; if both are 0 then we have reached the end of the string
loadi $1 1
ret
inc $4
inc $5
inc $3
tx $1 $3 ;check expected length
tx $2 $6 ;check max length
jneq +3 ; if expected_length == max_length
loadi $1 1 ; return true
ret
jmp strcmp_loop
@ -92,6 +108,34 @@ label shift_terminal:
ret
label disassemble:
call string_to_num
ijmp $1 ;;lol
ret
label do_shell:
loadi $4 @command_line_input
loadi $5 quit_label
loadi $6 4
call strcmp
loadi $2 1
jneq +2 ; if the command is QUIT, then hlt the machine!! A shell is born
hlt
loadi $4 @command_line_input
loadi $5 diss_label
loadi $6 4
call strcmp
loadi $2 1
jneq +5 ; if the command is QUIT, then hlt the machine!! A shell is born
loadi $4 @command_line_input
loadi $5 5
add $4 $5 $4
call disassemble
ret
label handle_keypress:
; Check for Backspace
@ -104,13 +148,8 @@ label handle_keypress:
; Check for Return
loadi $1 $0A
tx $2 $4
jneq +9
loadi $4 @command_line_input
loadi $5 quit_label
call strcmp
loadi $2 1
jneq +2 ; if the command is QUIT, then hlt the machine!! A shell is born
hlt
jneq +4
call do_shell
call shift_terminal
ret

24
src/assembler.rs
View File

@ -125,6 +125,18 @@ impl ImageAssembler {
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"jlt" => {
let addr = self.parse_addr(command_parts[1]);
self.memory[self.ptr] = 0xE4000000 + addr;
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"jgt" => {
let addr = self.parse_addr(command_parts[1]);
self.memory[self.ptr] = 0xE3000000 + addr;
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"call" => {
let addr = self.parse_addr(command_parts[1]);
self.memory[self.ptr] = 0xC1000000 + addr;
@ -137,6 +149,12 @@ impl ImageAssembler {
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"ijmp" => {
let addr = self.parse_addr(command_parts[1]);
self.memory[self.ptr] = 0xEF000000 + addr;
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"import" => {
self.assemble(command_parts[1]);
}
@ -251,6 +269,12 @@ impl ImageAssembler {
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"lshift" => {
self.memory[self.ptr] =
(0xa7 << 24) + (a_reg << 16) + (b_reg << 8) + result_reg;
println!("{:X}: {:X}", self.ptr, self.memory[self.ptr]);
self.ptr += 1;
}
"shift" => {
self.memory[self.ptr] =
(0xa5 << 24) + (a_reg << 16) + (b_reg << 8) + result_reg;

28
src/lib.rs
View File

@ -193,6 +193,16 @@ impl Machine {
let result = source & bits;
self.memory[REGISTER_PAGE + dest_reg] = result;
}
// LSHIFT A >> B => C
0xA7 => {
let source_reg = ((instruction & 0x00FF0000) >> 16) as usize;
let bit_reg = ((instruction & 0x0000FF00) >> 8) as usize;
let dest_reg = (instruction & 0xFF) as usize;
let source = self.memory[REGISTER_PAGE + source_reg];
let bits = self.memory[REGISTER_PAGE + bit_reg];
let result = source << bits;
self.memory[REGISTER_PAGE + dest_reg] = result;
}
op => {
unimplemented!("0x0 Addition Instruction {}", op)
}
@ -276,6 +286,24 @@ impl Machine {
self.memory[REGISTER_PAGE] = mem - 1;
}
}
0xE3 => {
// JMP ADDR if R(1) > R(2)
if self.memory[REGISTER_PAGE + 1] > self.memory[REGISTER_PAGE + 2] {
let mem = instruction & 0x00FFFFFF;
self.memory[REGISTER_PAGE] = mem - 1;
}
}
0xE4 => {
// JMP ADDR if R(1) > R(2)
if self.memory[REGISTER_PAGE + 1] < self.memory[REGISTER_PAGE + 2] {
let mem = instruction & 0x00FFFFFF;
self.memory[REGISTER_PAGE] = mem - 1;
}
}
0xEf => {
let mem = instruction & 0x0000FF;
self.memory[REGISTER_PAGE] = self.memory[REGISTER_PAGE+mem as usize]-1;
}
op => {
unimplemented!("0x0 JMP Instruction {}", op)
}

38
strings.asm
View File

@ -148,4 +148,40 @@ label num_to_char:
loadi $2 char_space
add $2 $1 $1 ; Add to Char Space
tx $4 $1
ret
ret
; $4 contains pointer to a null terminated hex string
; outputs num in $1
label string_to_num:
loadi $3 0
loadi $5 4 ; bits to shift each time
label string_to_num_inner:
rload $4 $1 ; load char at $4 into $1
loadi $2 $0 ; check that it isn't a null terminator
jneq +3
tx $1 $3
ret
; check this is a valid char
loadi $2 20
jgt +3
loadi $1 0
ret
; sub 0x30 from char to get a normalized number
loadi $2 $30
sub $1 $2 $1
loadi $2 $A
jlt +3
loadi $2 $7
sub $1 $2 $1
lshift $3 $5 $3
add $1 $3 $3
inc $4
jmp string_to_num_inner
ret