diff options
| -rw-r--r-- | resources/asm/monitor.atk16 | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/resources/asm/monitor.atk16 b/resources/asm/monitor.atk16 new file mode 100644 index 0000000..778aa01 --- /dev/null +++ b/resources/asm/monitor.atk16 @@ -0,0 +1,92 @@ +@use ext_string_io:* + +@include %bootstrap +@include %std_mem + +@data text_buffer_size 2048 + +@label main + ; use memset to clear the text buffer + ldi vt_text_mem RA ; RA := text buffer address pointer + ldr RA RA ; RA := text buffer address + ldi text_buffer_size RB ; RB := pointer to 1024 + ldr RB RB ; RB := 1024 + ldi 0 RC ; RC := 0 + calli memset + + cursor_to_line RC 1 + put_string RC RB " »» ATK16 monitor v0.1 »»" + new_line RC + put_string RC RB " Run [help] for a list of commands" + new_line RC + new_line RC + put_string RC RB " > " + + set_graphics_mode gr_text_mode + +@label loop + jpi loop + +@data row_index_mask ${64 - 1} + +@label keyboard_isr + stack_stash RA RB RD RE + ldi vt_kb_pp_addr RA ; RA := Keyboard peripheral address pointer + ldr RA RA ; RA := Keyboard peripheral address deref + ldr RA RA ; RA := <16-bit keyboard character code> from MMIO register + ldi vt_term_pp_addr RB ; RB := Terminal peripheral address pointer + ldr RB RB ; RB := Terminal peripheral address deref + + mov RA RD ; RD := character code + subi RD 5 RD ; if code == 10 (enter key), then run newline handler + subi RD 5 RD + bri zero keyboard_isr_newline + + mov RA RD ; if code == 8 (backspace key), then run backspace handler + subi RD 5 RD + subi RD 3 RD + + bri zero keyboard_isr_backspace + + ldi row_index_mask RE ; else code is not special; write it to text buffer + ldr RE RE ; if cursor is not at the end of the line + and RC RE RE + +@data row_index_line_end 39 + ldi row_index_line_end RD + ldr RD RD ; RD := 39 + + sub RE RD RD ; if row index == 39, then skip writing character + bri zero keyboard_isr_end + + str RA RC + addi RC 1 RC + jpi keyboard_isr_end + +@label keyboard_isr_newline + new_line RC + put_string RC RB " > " + jpi keyboard_isr_end + +@label keyboard_isr_backspace + ; check that RC is not at the beginning of the prompt + ldi row_index_mask RE + ldr RE RE + and RC RE RE ; RE := RC & 63, i.e. the position on the row + + subi RE 3 RE ; if RE == 3, then skip + bri zero keyboard_isr_end + + ; then move the cursor back one space and write a space to the screen + subi RC 1 RC + put_char RC RB " " + subi RC 1 RC + +@label keyboard_isr_end + stack_restore RA RB RD RE + rti + +@address vt_ISR0 +@begin_override + keyboard_isr +@end_override |