https://github.com/akkartik/mu/blob/main/305keyboard.subx
  1 # Primitives for keyboard control.
  2 # Require Linux and a modern terminal.
  3 
  4 == code
  5 
  6 enable-keyboard-immediate-mode:
  7     # . prologue
  8     55/push-ebp
  9     89/<- %ebp 4/r32/esp
 10     # . save registers
 11     50/push-eax
 12     51/push-ecx
 13     52/push-edx
 14     53/push-ebx
 15     56/push-esi
 16     57/push-edi
 17     #
 18     (_maybe-open-terminal)
 19     # var terminal-info/esi: (addr termios)
 20     # termios is a type from the Linux kernel. We don't care how large it is.
 21     81 5/subop/subtract %esp 0x100/imm32
 22     89/<- %esi 4/r32/esp
 23     # ioctl(*Terminal-file-descriptor, TCGETS, terminal-info)
 24     89/<- %edx 6/r32/esi
 25     b9/copy-to-ecx 0x5401/imm32/TCGETS
 26     8b/-> *Terminal-file-descriptor 3/r32/ebx
 27     e8/call syscall_ioctl/disp32
 28     # terminal-info->c_iflags &= Keyboard-immediate-mode-iflags
 29 #?     (write-buffered Stderr "iflags before: ")
 30 #?     (write-int32-hex-buffered Stderr *esi)
 31 #?     (write-buffered Stderr Newline)
 32 #?     (flush Stderr)
 33     8b/-> *esi 0/r32/eax  # Termios-c_iflag
 34     23/and *Keyboard-immediate-mode-iflags 0/r32/eax
 35     89/<- *esi 0/r32/eax  # Termios-c_iflag
 36 #?     (write-buffered Stderr "iflags after: ")
 37 #?     (write-int32-hex-buffered Stderr *esi)
 38 #?     (write-buffered Stderr Newline)
 39 #?     (flush Stderr)
 40     # terminal-info->c_lflags &= Keyboard-immediate-mode-lflags
 41 #?     (write-buffered Stderr "lflags before: ")
 42 #?     (write-int32-hex-buffered Stderr *(esi+0xc))
 43 #?     (write-buffered Stderr Newline)
 44 #?     (flush Stderr)
 45     8b/-> *(esi+0xc) 0/r32/eax  # Termios-c_lflag
 46     23/and *Keyboard-immediate-mode-lflags 0/r32/eax
 47     89/<- *(esi+0xc) 0/r32/eax  # Termios-c_lflag
 48 #?     (write-buffered Stderr "lflags after: ")
 49 #?     (write-int32-hex-buffered Stderr *(esi+0xc))
 50 #?     (write-buffered Stderr Newline)
 51 #?     (flush Stderr)
 52     # ioctl(*Terminal-file-descriptor, TCSETS, terminal-info)
 53     89/<- %edx 6/r32/esi
 54     b9/copy-to-ecx 0x5402/imm32/TCSETS
 55     8b/-> *Terminal-file-descriptor 3/r32/ebx
 56     e8/call syscall_ioctl/disp32
 57 $enable-keyboard-immediate-mode:end:
 58     # . reclaim locals
 59     81 0/subop/add %esp 0x100/imm32
 60     # . restore registers
 61     5f/pop-to-edi
 62     5e/pop-to-esi
 63     5b/pop-to-ebx
 64     5a/pop-to-edx
 65     59/pop-to-ecx
 66     58/pop-to-eax
 67     # . epilogue
 68     89/<- %esp 5/r32/ebp
 69     5d/pop-to-ebp
 70     c3/return
 71 
 72 enable-keyboard-type-mode:
 73     # . prologue
 74     55/push-ebp
 75     89/<- %ebp 4/r32/esp
 76     # . save registers
 77     50/push-eax
 78     51/push-ecx
 79     52/push-edx
 80     53/push-ebx
 81     56/push-esi
 82     57/push-edi
 83     #
 84     (_maybe-open-terminal)
 85     # var terminal-info/esi: (addr termios)
 86     # termios is a type from the Linux kernel. We don't care how large it is.
 87     81 5/subop/subtract %esp 0x100/imm32
 88     89/<- %esi 4/r32/esp
 89     # ioctl(*Terminal-file-descriptor, TCGETS, terminal-info)
 90     89/<- %edx 6/r32/esi
 91     b9/copy-to-ecx 0x5401/imm32/TCGETS
 92     8b/-> *Terminal-file-descriptor 3/r32/ebx
 93     e8/call syscall_ioctl/disp32
 94     # terminal-info->c_iflags |= Keyboard-type-mode-iflags
 95     8b/-> *esi 0/r32/eax  # Termios-c_iflag
 96     0b/or *Keyboard-type-mode-iflags 0/r32/eax
 97     89/<- *esi 0/r32/eax  # Termios-c_iflag
 98     # terminal-info->c_lflags |= Keyboard-type-mode-lflags
 99     8b/-> *(esi+0xc) 0/r32/eax  # Termios-c_lflag
100     0b/or *Keyboard-type-mode-lflags 0/r32/eax
101     89/<- *(esi+0xc) 0/r32/eax  # Termios-c_lflag
102     # ioctl(*Terminal-file-descriptor, TCSETS, terminal-info)
103     89/<- %edx 6/r32/esi
104     b9/copy-to-ecx 0x5402/imm32/TCSETS
105     8b/-> *Terminal-file-descriptor 3/r32/ebx
106     e8/call syscall_ioctl/disp32
107 $enable-keyboard-type-mode:end:
108     # . reclaim locals
109     81 0/subop/add %esp 0x100/imm32
110     # . restore registers
111     5f/pop-to-edi
112     5e/pop-to-esi
113     5b/pop-to-ebx
114     5a/pop-to-edx
115     59/pop-to-ecx
116     58/pop-to-eax
117     # . epilogue
118     89/<- %esp 5/r32/ebp
119     5d/pop-to-ebp
120     c3/return
121 
122 # read keys or escapes up to 4 bytes
123 #
124 # fun fact: terminal escapes and graphemes in utf-8 don't conflict!
125 # - in graphemes all but the first/lowest byte will have a 1 in the MSB (be
126 #   greater than 0x7f)
127 # - in escapes every byte will have a 0 in the MSB
128 # the two categories overlap only when the first/lowest byte is 0x1b or 'esc'
129 #
130 # Only use this in immediate mode; in type (typewriter) mode 4 bytes may get
131 # parts of multiple keys.
132 read-key-from-real-keyboard:  # -> result/eax: grapheme
133     # . prologue
134     55/push-ebp
135     89/<- %ebp 4/r32/esp
136     # . save registers
137     51/push-ecx
138     # var buf/ecx: (stream byte 4)
139     68/push 0/imm32/data
140     68/push 4/imm32/size
141     68/push 0/imm32/read
142     68/push 0/imm32/write
143     89/<- %ecx 4/r32/esp
144     #
145     (read 0 %ecx)  # => eax
146     8b/-> *(ecx+0xc) 0/r32/eax
147 $read-key-from-real-keyboard:end:
148     # . reclaim locals
149     81 0/subop/add %esp 0x10/imm32
150     # . restore registers
151     59/pop-to-ecx
152     # . epilogue
153     89/<- %esp 5/r32/ebp
154     5d/pop-to-ebp
155     c3/return
156 
157 # use this in type mode
158 read-line-from-real-keyboard:  # out: (addr stream byte)
159     # . prologue
160     55/push-ebp
161     89/<- %ebp 4/r32/esp
162     #
163     (read-line-buffered Stdin *(ebp+8))
164 $read-line-from-real-keyboard:end:
165     # . epilogue
166     89/<- %esp 5/r32/ebp
167     5d/pop-to-ebp
168     c3/return
169 
170 == data
171 
172 # iflags:   octal     hex
173 #  IGNBRK  0000001   0x0001
174 #  BRKINT  0000002   0x0002
175 #  IGNPAR  0000004   0x0004
176 #  PARMRK  0000010   0x0008
177 #  INPCK   0000020   0x0010
178 #  ISTRIP  0000040   0x0020
179 #  INLCR   0000100   0x0040
180 #  IGNCR   0000200   0x0080
181 #  ICRNL   0000400   0x0100
182 #  IUCLC   0001000   0x0200
183 #  IXON    0002000   0x0400
184 #  IXANY   0004000   0x0800
185 #  IXOFF   0010000   0x1000
186 #  IMAXBEL 0020000   0x2000
187 #  IUTF8   0040000   0x4000
188 
189 # lflags:
190 #  ISIG   0000001     0x0001
191 #  ICANON 0000002     0x0002
192 #  ECHO   0000010     0x0008
193 #  ECHOE  0000020     0x0010
194 #  ECHOK  0000040     0x0020
195 #  ECHONL 0000100     0x0040
196 #  NOFLSH 0000200     0x0080
197 #  TOSTOP 0000400     0x0100
198 #  IEXTEN 0100000     0x8000
199 
200 # recipe for raw mode according to the termios.3 manpage on Linux:
201 #   termios_p->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
202 #   termios_p->c_oflag &= ~OPOST;
203 #   termios_p->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
204 #   termios_p->c_cflag &= ~(CSIZE | PARENB);
205 #   termios_p->c_cflag |= CS8;
206 
207 Keyboard-immediate-mode-iflags:  # (addr tcflag_t)
208 #?     0xfffffa14  # ~IGNBRK & ~BRKINT & ~PARMRK & ~ISTRIP & ~INLCR & ~IGNCR & ~ICRNL & ~IXON
209     0xffffffff/imm32
210 
211 Keyboard-immediate-mode-lflags:  # (addr tcflag_t)
212 #?     0xffff7fb4/imm32  # ~ICANON & ~ISIG & ~IEXTEN & ~ECHO & ~ECHONL
213     0xffffffb5/imm32  # ~ICANON & ~ECHO & ~ECHONL
214 
215 Keyboard-type-mode-iflags:  # (addr tcflag_t)
216     0x00000000/imm32  # ~Keyboard-immediate-mode-iflags
217 
218 Keyboard-type-mode-lflags:  # (addr tcflag_t)
219     0x0000004a/imm32  # ~Keyboard-immediate-mode-lflags