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fix fatal bug in data, get prefix down, start work on awaiting_label, add debug function, more

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andromeda
2026-04-02 00:13:47 +02:00
parent 395c42dff4
commit 18125e6b20
2 changed files with 165 additions and 36 deletions
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28
twasm/README.md
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@@ -95,15 +95,15 @@ label definitions are stored and recalled from this table. The memory addresses
```
16 bytes
+---------+
| 127 64 |
+---------+
| address |
+---------+
| 63 0 |
+---------+
| hash |
+---------+
+----------+---------+
| 127 96 | 95 64 |
+----------+---------+
| reserved | address |
+----------+---------+
| 63 0 |
+--------------------+
| hash |
+--------------------+
```
#### awaiting label table (ALT)
@@ -113,7 +113,7 @@ forward references are stored in this table to be filled in after assembly is ot
```
16 bytes
+----------+----------+------------------+---------+
| 127 105 | 104 104 | 103 96 | 95 64 |
| 127 101 | 100 | 99 96 | 95 64 |
+----------+----------+------------------+---------+
| reserved | abs flag | # bytes reserved | address |
+----------+----------+------------------+---------+
@@ -263,7 +263,7 @@ entries are as follows:
| 63 56 | 55 48 | 47 40 | 39 32 |
+----------+---------------+---------------+------------------+
| opcode | opcode | opcode | opcode |
| dst=rel8 | dest=rel | dst=imm8 | dst=imm |
| dst=rel8 | dst=rel | dst=imm8 | dst=imm |
+----------+---------------+---------------+------------------+
| 31 24 | 23 16 | 15 0 |
+----------+---------------+----------------------------------+
@@ -319,7 +319,8 @@ rel ; rel 16/32
rel8 ; rel 8
opX&8 ; low 8 bits are the operator flag that goes with opcode at offset X from
; the first opcode in the table entry
; the first opcode in the table entry. High bit is (somewhat confusingly)
; a flag for whether or not the operator comes with an `0F` prefix
```
note much room to expand. If an opcode doesn't exist, it should be 0x00
@@ -431,8 +432,7 @@ supported tokens are listed below
| db | 0x0100 | pseudo-operator |
| | 0x10XX | some memory address; `XX` is as specified below |
| | 0x20XX | some constant; `XX` is as specified below |
| | 0x3XXX | some label definition; `XXX` is its entry index in the label table |
| | 0x4XXX | some label reference; `XXX` is its entry index in the label table
| | 0x3XXX | some label; `XXX` is its entry index in the label table |
| | 0xFEXX | used to pass some raw value `XX` in place of a token id to a couple of functions that mention this as a feature. If the function doesn't mention it, it will lead to undefined behaviour |
| | 0xFFFF | unrecognised token |

173
twasm/asm/main.asm
View File

@@ -112,16 +112,23 @@ assemble:
jmp .unexpected_token ; otherwise, fail
dq 0,0,0 ; TODO figure out why this does anything and fix it :shrug:
.label:
push rsi
mov rsi, .msg_label
call print.debug
pop rsi
mov esi, [.next_output_byte]
sub esi, OUTPUT_ADDR ; esi = relative address of label to start of program
and edi, 0xFFF ; edi = index to add address hash to
call add_label_address
jmp .loop_next_token
.operator:
push rdi
; di = tte of operator
call get_tte_typed_metadata
; al = tte typed metadata
pop rdi ; di = tte of operator
cmp al, UNRECOGNISED_ID_METADATA ; make sure token has metadata on record
je .unexpected_token ; if not, fail
@@ -144,8 +151,9 @@ assemble:
call print.debug
pop rsi
; di = tte of operator
mov sil, 0b ; opcode
; di = tte of operator
mov sil, 0b ; opcode
xor ebx, ebx ; no flags
call get_opcode
; al = opcode
; dl = 0x00
@@ -158,18 +166,45 @@ assemble:
call print.debug
pop rsi
; di = tte of operator
mov sil, 0b ; dst=r/m
push rdi
call .next_token
jge .break
call .get_next_tte
mov rcx, rdi ; cx = operand tte
pop rdi
push rcx
; di = tte of operator
mov sil, 0 ; dst=r/m
xor ebx, ebx ; no flags
shr ecx, 12
and ecx, 0xF
cmp ecx, 0x3
je .operator_1_get_opcode_label
jmp .operator_1_get_opcode_continue
.operator_1_get_opcode_label:
mov sil, 4 ; dst=rel
.operator_1_get_opcode_continue:
call get_opcode
; al = opcode
; dl = op flag
push rdx
and dl, 1000b
cmp dl, 1000b
jne .operator_1_write_prefix_continue
.operator_1_write_prefix
push rax
mov al, 0x0F
call .write_byte
pop rax ; al = opcode
.operator_1_write_prefix_continue
call .write_byte
pop rdx ; dl = op flag
call .next_token
jge .break
call .get_next_tte
pop rdi ; di = next tte
push rdi
and di, 0xFF00
@@ -177,15 +212,20 @@ assemble:
pop rdi ; di = next tte
je .operator_1_memory
push rdi
push rdx
; di = next tte
call get_tte_type
; al = type of token
pop rdx ; dl = op flag
pop rdi ; di = next tte
cmp al, 0x02 ; type: register
je .operator_1_register
cmp al, 0x04 ; type: label reference
je .operator_1_label
jmp .unexpected_token
.operator_1_memory:
push rsi
@@ -227,13 +267,34 @@ assemble:
.operator_1_register_no_prefix:
mov si, di ; si = `R/M` tte
and edx, 0xFF
or edx, 0xFE00 ; pass di as direct value
mov edi, edx ; di = op flag
mov edx, 11b ; dl = mod bits
or edx, 0xFE00 ; pass di as direct value
mov edi, edx ; di = op flag
mov edx, 11b ; dl = mod bits
call get_ModRM
; al = Mod R/M byte
call .write_byte
jmp .loop_next_token
.operator_1_label:
push rsi
mov rsi, .msg_operator_1_label
call print.debug
pop rsi
mov esi, [.next_output_byte]
sub esi, OUTPUT_ADDR ; esi = relative address of label reference to start
; of program
mov eax, 0x04 ; al = first 4 bits: # bytes reserved
; 5th bit: abs flag
and edi, 0xFFF ; edi = index of hash
call add_awaiting_label
mov al, 0xFF ; reserve space
call .write_byte
call .write_byte
call .write_byte
call .write_byte
jmp .loop_next_token
.operator_2:
push rsi
@@ -274,6 +335,7 @@ assemble:
mov edi, ecx ; di = tte of operator
xor esi, esi ; dst=r/m; src=r
xor ebx, ebx ; no flags
call get_opcode
; al = opcode
; dl = op flag
@@ -435,7 +497,7 @@ assemble:
push rsi
mov di, cx ; di = tte of operator
mov sil, 1 ; dst = reg
mov bl, 1 ; bl = operator flag byte
; bl = operator flag byte
call get_opcode
; al = opcode
; dl = op flag
@@ -614,7 +676,6 @@ assemble:
mov di, cx ; di = tte of operator
mov sil, 2 ; dst=r/m,src=imm
; bl = operator flag byte
; TODO change sil based on whether bl is 8 bit or not
push rbx
and ebx, 1
cmp bl, 1 ; bit8 flag
@@ -629,7 +690,14 @@ assemble:
; dl = op flag
; TODO do something if the op flag is present
call .write_byte
pop rsi ; si = tte
mov edi, edx ; si = op flag
and edi, 0xFF
or edi, 0xFE00
pop rsi ; si = r/m; dst tte
mov edx, 11b ; dl = mod bits
call get_ModRM
; al = Mod R/M byte
call .write_byte
call .next_token
jge .break
@@ -834,6 +902,7 @@ assemble:
.msg_operator_1 db "operator_1", 0x0A, 0x00
.msg_operator_1_memory db "operator_1_memory", 0x0A, 0x00
.msg_operator_1_register db "operator_1_register", 0x0A, 0x00
.msg_operator_1_label db "operator_1_label", 0x0A, 0x00
.msg_operator_2 db "operator_2", 0x0A, 0x00
.msg_operator_2_memory db "operator_2_memory", 0x0A, 0x00
.msg_operator_2_memory_register db "operator_2_memory_register", 0x0A, 0x00
@@ -1014,7 +1083,9 @@ get_ModRM:
;
; returned:
; al = opcode; the rest of rax is zeroed.
; dl = lower 3 bits: op flag, if applicable. The rest of rdx is zeroed.
; dl = lower 3 bits: op flag, if applicable.
; 4th bit: 0x0F prefix flag
; the rest of rdx is zeroed.
; ------------------------------------------------------------------------------
get_opcode:
@@ -1112,6 +1183,7 @@ get_reg_bits:
; rax = number of tokens processed
; ------------------------------------------------------------------------------
align 16 ; idk, fixes some alignment bug sometimes :/
tokenise:
; rdi -> current byte of program
add rsi, rdi ; rsi -> last byte of program
@@ -1952,6 +2024,25 @@ print:
.test_msg db 0x1B, "[1;33m", "[TEST]: ", 0x1B, "[0m", 0x00
.warn_msg db 0x1B, "[1;35m", "[WARN]: ", 0x1B, "[0m", 0x00
; ------------------------------------------------------------------------------
; print_least_4_bits
;
; description:
; prints the least significant 4 bits of rax for debugging reasons
; ------------------------------------------------------------------------------
print_least_4_bits:
push rax
push rsi
add eax, 0x30
mov [.byte], al
mov rsi, .byte
call print.warn
pop rsi
pop rax
ret
.byte db 0x00, 0x0A, 0x00
; ------------------------------------------------------------------------------
; halt
;
@@ -2123,7 +2214,7 @@ add_label_hash:
;
; parameters
; rdi = lower 3 bytes: index of label table to add the address to
; rsi = 64-bit address to be added, relative to start of program
; esi = 32-bit address to be added, relative to start of program
;
; returned
; rax = return value: 0 = success
@@ -2133,16 +2224,52 @@ add_label_hash:
add_label_address:
and edi, 0xFFF
shl rdi, 4 ; rdi * 16
mov rax, [LABEL_TABLE_ADDR + rdi]
cmp rax, 0
mov eax, [LABEL_TABLE_ADDR + 8 + rdi]
cmp eax, 0
jne .ret_1
mov [LABEL_TABLE_ADDR + 16 + rdi], rsi
mov [LABEL_TABLE_ADDR + 8 + rdi], esi
xor eax, eax
ret
.ret_1:
mov eax, 1
ret
; ------------------------------------------------------------------------------
; add_awaiting_label
;
; description:
; adds metadata of a forward reference to be completed in a later pass
;
; parameters
; rdi = lower 3 bytes: index of label table this forward reference is awaiting
; esi = 32-bit address of reference, relative to start of program
; al = lower 4 bytes: # bytes reserved at [OUTPUT_ADDR + esi] for the reference
; byte 5: abs flag if the reference is absolute
; ------------------------------------------------------------------------------
add_awaiting_label:
and edi, 0xFFF
and esi, esi
and eax, 0x1F
push rax
xor eax, eax
.loop:
cmp rax, AWAITING_LABEL_TABLE_SIZE
jge .break
mov rcx, [AWAITING_LABEL_TABLE_SIZE + rax]
cmp rcx, 0 ; empty slot
je .break
add rax, 16
jmp .loop
.break:
pop rcx ; cl = bits passed to al
shl rdi, 4
mov rdx, [LABEL_TABLE_ADDR + rdi]
mov [AWAITING_LABEL_TABLE_ADDR + rax], rdx ; hash
mov [AWAITING_LABEL_TABLE_ADDR + 8 + rax], esi ; address
mov [AWAITING_LABEL_TABLE_ADDR + 13 + rax], cl ; bits passed to al
ret
; ------------------------------------------------------------------------------
; clear_token_table
;
@@ -2818,6 +2945,8 @@ opcodes:
; 00:
; 01: bit8 flag
dd 0x00000000
; jmp
dw 0x005C
db 0xFF ; r/m
@@ -2840,12 +2969,12 @@ opcodes:
dw 0x0000
dw 0x0000
db 0x00 ; TODO figure out the 0x0F prefix this will need
db 0x84 ; rel16/32
db 0x74 ; rel8
dd 0x00000000 ; 00000:
; 0: rel8
; 00:
dd 0x00080000 ; 0000:
; 8: rel16/32 0x0F flag
; 000:
dd 0x00000000