about summary refs log blame commit diff stats
path: root/subx/teensy/test7-global.s
blob: 4cb4e8f34b00b82023e6b958d50a06e0a6ca9ba0 (plain) (tree) 
c1100182 ^


























































1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58


























































                                                                       
; https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
; nasm -f bin test7-global.s -o test7
; chmod +x test7
BITS 32

              org     0x08048000

ehdr:                                                 ; Elf32_Ehdr
              db      0x7F, "ELF", 1, 1, 1, 0         ;   e_ident
      times 8 db      0
              dw      2                               ;   e_type
              dw      3                               ;   e_machine
              dd      1                               ;   e_version
              dd      _start                          ;   e_entry
              dd      phdr1 - $$                      ;   e_phoff
              dd      0                               ;   e_shoff
              dd      0                               ;   e_flags
              dw      ehdrsize                        ;   e_ehsize
              dw      phdrsize                        ;   e_phentsize
              dw      2                               ;   e_phnum
              dw      0                               ;   e_shentsize
              dw      0                               ;   e_shnum
              dw      0                               ;   e_shstrndx
ehdrsize  equ  $ - ehdr

phdr1:                                                ; Elf32_Phdr
              dd      1                               ;   p_type
              dd      0                               ;   p_offset
              dd      $$                              ;   p_vaddr
              dd      $$                              ;   p_paddr
              dd      codesize                        ;   p_filesz
              dd      codesize                        ;   p_memsz
              dd      5                               ;   p_flags = r-x
              dd      0x1000                          ;   p_align
phdrsize  equ  $ - phdr1

phdr2:
              dd      1                               ;   p_type
              dd      _data - $$                      ;   p_offset
              dd      _data                           ;   p_vaddr
              dd      _data                           ;   p_paddr
              dd      datasize                        ;   p_filesz
              dd      datasize                        ;   p_memsz
              dd      6                               ;   p_flags = rw-
              dd      0x1000                          ;   p_align

_start:
  mov ebx, [foo]
  mov eax, 1
  int 0x80

codesize      equ     $ - $$  ; TODO: why include the headers?!

alignb 0x1000
_data:
  foo:        dd      42

datasize      equ     $ - _data
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-08-19 09:35:15 +0000
/span> 9 # > 1 + 3*4 # 13 # > ^D # $ # # Error handling is non-existent. This is just a prototype. fn main -> _/ebx: int { enable-keyboard-immediate-mode var look/esi: grapheme <- copy 0 # lookahead var n/eax: int <- copy 0 # result of each expression print-string 0/screen, "press ctrl-c or ctrl-d to exit\n" # read-eval-print loop { # print prompt print-string 0/screen, "> " # read and eval n, look <- simplify # we explicitly thread 'look' everywhere # if (look == 0) break compare look, 0 break-if-= # print print-int32-decimal 0/screen, n print-string 0/screen, "\n" # loop } enable-keyboard-type-mode return 0 } fn simplify -> _/eax: int, _/esi: grapheme { # prime the pump var look/esi: grapheme <- get-char # do it var result/eax: int <- copy 0 result, look <- expression look return result, look } fn expression _look: grapheme -> _/eax: int, _/esi: grapheme { var look/esi: grapheme <- copy _look # read arg var result/eax: int <- copy 0 result, look <- term look $expression:loop: { # while next non-space char in ['+', '-'] look <- skip-spaces look { var continue?/eax: boolean <- is-add-or-sub? look compare continue?, 0/false break-if-= $expression:loop } # read operator var op/ecx: grapheme <- copy 0 op, look <- operator look # read next arg var second/edx: int <- copy 0 look <- skip-spaces look { var tmp/eax: int <- copy 0 tmp, look <- term look second <- copy tmp } # reduce $expression:perform-op: { { compare op, 0x2b/+ break-if-!= result <- add second break $expression:perform-op } { compare op, 0x2d/minus break-if-!= result <- subtract second break $expression:perform-op } } loop } look <- skip-spaces look return result, look } fn term _look: grapheme -> _/eax: int, _/esi: grapheme { var look/esi: grapheme <- copy _look # read arg look <- skip-spaces look var result/eax: int <- copy 0 result, look <- factor look $term:loop: { # while next non-space char in ['*', '/'] look <- skip-spaces look { var continue?/eax: boolean <- is-mul-or-div? look compare continue?, 0/false break-if-= $term:loop } # read operator var op/ecx: grapheme <- copy 0 op, look <- operator look # read next arg var second/edx: int <- copy 0 look <- skip-spaces look { var tmp/eax: int <- copy 0 tmp, look <- factor look second <- copy tmp } # reduce $term:perform-op: { { compare op, 0x2a/* break-if-!= result <- multiply second break $term:perform-op } #? { #? compare op, 0x2f/slash #? break-if-!= #? result <- divide second # not in Mu yet #? break $term:perform-op #? } } loop } return result, look } fn factor _look: grapheme -> _/eax: int, _/esi: grapheme { var look/esi: grapheme <- copy _look # should be a no-op look <- skip-spaces look # if next char is not '(', parse a number compare look, 0x28/open-paren { break-if-= var result/eax: int <- copy 0 result, look <- num look return result, look } # otherwise recurse look <- get-char # '(' var result/eax: int <- copy 0 result, look <- expression look look <- skip-spaces look look <- get-char # ')' return result, look } fn is-mul-or-div? c: grapheme -> _/eax: boolean { compare c, 0x2a/* { break-if-!= return 1/true } compare c, 0x2f/slash { break-if-!= return 1/true } return 0/false } fn is-add-or-sub? c: grapheme -> _/eax: boolean { compare c, 0x2b/+ { break-if-!= return 1/true } compare c, 0x2d/minus { break-if-!= return 1/true } return 0/false } fn operator _look: grapheme -> _/ecx: grapheme, _/esi: grapheme { var op/ecx: grapheme <- copy _look var look/esi: grapheme <- get-char return op, look } fn num _look: grapheme -> _/eax: int, _/esi: grapheme { var look/esi: grapheme <- copy _look var result/edi: int <- copy 0 { var first-digit/eax: int <- to-decimal-digit look result <- copy first-digit } { look <- get-char # done? var digit?/eax: boolean <- is-decimal-digit? look compare digit?, 0/false break-if-= # result *= 10 { var ten/eax: int <- copy 0xa result <- multiply ten } # result += digit(look) var digit/eax: int <- to-decimal-digit look result <- add digit loop } return result, look } fn skip-spaces _look: grapheme -> _/esi: grapheme { var look/esi: grapheme <- copy _look # should be a no-op { compare look, 0x20 break-if-!= look <- get-char loop } return look } fn get-char -> _/esi: grapheme { var look/eax: grapheme <- read-key-from-real-keyboard print-grapheme-to-real-screen look compare look, 4 { break-if-!= print-string 0/screen, "^D\n" syscall_exit } return look }
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-08-19 09:35:10 +0000