222 lines
5.2 KiB
NASM
222 lines
5.2 KiB
NASM
LOAD_ADDR equ 0x00010000 ; address this program is loaded at
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TOKEN_TABLE_ADDR equ 0x00060000 ; address the token table is loaded at
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TOKEN_TABLE_SIZE equ 0x1000 ; max length of table
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TEST_ARENA_ADDR equ 0x00060000 ; address to run tests at
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TEST_ARENA_SIZE equ 0x1000 ; maximum size tests can use
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OUTPUT_ADDR equ 0x00070000 ; address of outputed binary
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OUTPUT_SIZE equ 0x1000 ; max length of outputed binary
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[bits 64]
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[org LOAD_ADDR]
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start:
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mov rsi, msg_welcome
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call print
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call run_tests
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jmp halt
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; ------------------------------------------------------------------------------
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; tokenising
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; ------------------------------------------------------------------------------
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; ------------------------------------------------------------------------------
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; copy_token
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;
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; description:
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; copies a token from one spot in memory to another
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;
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; parameters:
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; rdi -> start of buffer to be read
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; rsi -> start of buffer to be written
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;
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; returned:
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; rax -> last byte read
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; rdx -> last byte written
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; ------------------------------------------------------------------------------
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copy_token:
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.loop:
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mov al, [rdi] ; check if next char is a space
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cmp al, " "
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je .break
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call copy_byte ; copy the next byte if not
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inc rdi ; increment read- and write-pointers
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inc rsi
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jmp .loop ; and loop again
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.break:
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mov rax, rdi ; return values
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mov rdx, rsi
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ret
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.msg db "yo loop copy_token", 0x0D, 0x0A, 0x00
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; ------------------------------------------------------------------------------
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; copy_byte
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;
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; description:
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; copies a byte from one spot in memory to another
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;
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; parameters:
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; rdi -> word to be read
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; rsi -> word to be written
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;
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; returned:
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; rax = byte that was read
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; ------------------------------------------------------------------------------
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copy_byte:
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xor rax, rax ; zero out so it returns fine
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mov al, [rdi]
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mov [rsi], al
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ret
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; ------------------------------------------------------------------------------
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; utilities
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; ------------------------------------------------------------------------------
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; ------------------------------------------------------------------------------
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; print
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;
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; description:
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; prints a null-terminated string
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;
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; parameters:
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; rsi -> start of null-terminated string
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; ------------------------------------------------------------------------------
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print:
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push rdx
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mov rdx, 0x3F8
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.loop:
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mov al, [rsi]
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test al, al
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jz .done
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out dx, al
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inc rsi
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jmp .loop
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.done:
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pop rdx
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ret
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; ------------------------------------------------------------------------------
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; halt
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;
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; description:
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; halts the program, silly :)
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; ------------------------------------------------------------------------------
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halt:
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mov rsi, msg_halt
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call print
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hlt
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jmp halt
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; ------------------------------------------------------------------------------
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; tests
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; ------------------------------------------------------------------------------
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; ------------------------------------------------------------------------------
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; run_tests
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;
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; description:
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; runs all tests
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; ------------------------------------------------------------------------------
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run_tests:
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mov rsi, .msg
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call print
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call test_copy_byte
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call test_copy_token
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ret
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.msg db "running test suite...", 0x0D, 0x0A, 0x00
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; ------------------------------------------------------------------------------
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; test_copy_byte
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;
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; description:
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; tests copy_byte's described functionality
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; ------------------------------------------------------------------------------
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test_copy_byte:
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mov rsi, .msg
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call print
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mov rdi, test_byte ; byte to be copied
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mov rsi, TEST_ARENA_ADDR ; location of test
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call copy_byte
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mov cx, [rsi]
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and ax, 0xFF ; only compare bottom byte
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and cx, 0xFF
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cmp ax, cx ; compare returned byte to copied byte
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jne .fail
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cmp al, [test_byte] ; compare returned byte to expected byte
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jne .fail
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.pass:
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mov rsi, msg_pass
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call print
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ret
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.fail:
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mov rsi, msg_fail
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call print
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ret
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.msg db "test_copy_byte...", 0x00
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; ------------------------------------------------------------------------------
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; test_copy_token
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;
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; description:
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; tests copy_token described functionality
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; ------------------------------------------------------------------------------
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test_copy_token:
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mov rsi, .msg
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call print
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mov rdi, test_token ; read buffer
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mov rsi, TEST_ARENA_ADDR ; write buffer
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call copy_token
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; check reported final indicies with the expected final indicies
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cmp rax, test_token + 8 ; last byte read
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jne .fail
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cmp rdx, TEST_ARENA_ADDR + 8 ; last byte written
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jne .fail
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mov rsi, TEST_ARENA_ADDR
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mov rcx, [rsi]
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cmp rcx, [test_token] ; compare copied token to expected token
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jne .fail
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.pass:
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mov rsi, msg_pass
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call print
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ret
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.fail:
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mov rsi, msg_fail
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call print
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ret
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.msg db "test_copy_token...", 0x00
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; ------------------------------------------------------------------------------
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; data
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; ------------------------------------------------------------------------------
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msg_welcome db "Welcome to Twasm", 0x0D, 0x0A, 0x00
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msg_halt db "halted.", 0x0D, 0x0A, 0x00
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msg_pass db "passed.", 0x0D, 0x0A, 0x00
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msg_fail db "failed.", 0x0D, 0x0A, 0x00
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test_byte db "T"
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test_token db "TestTokn " ; followed by space. Quad word
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