izaya/collapseos
1
1
Fork 0
Code Issues Pull Requests Releases Wiki Activity

kbd: support shifted characters

Browse Source
This commit is contained in:
Virgil Dupras 2019-07-21 17:30:50 -04:00
parent 52e5f5b5bf
commit f43241a5a0
1 changed files with 58 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
kernel/kbd.asm
View File

@ -36,19 +36,31 @@ kbdGetC:
; Do we need to skip it?
ex af, af' ; save fetched KC
ld a, (KBD_PREV_KC)
; Whatever the KC, the new A becomes our prev. The easiest way to do
; this is to do it now.
ex af, af' ; restore KC
ld (KBD_PREV_KC), a
ex af, af' ; restore prev KC
; If F0 (break code) or E0 (extended code), we skip this code
cp KBD_KC_BREAK
jr z, .skip
jr z, .break
cp KBD_KC_EXT
jr z, .skip
jr z, .ignore
ex af, af' ; restore saved KC
ld (KBD_PREV_KC), a
cp 0x80
jr nc, .outOfBounds
; No need to skip, code within bounds, we have something! Let's see if
; there's a ASCII code associated to it.
jr nc, .ignore
; No need to skip, code within bounds, we have something!
call .isShift
jr z, .shiftPressed
; Let's see if there's a ASCII code associated to it.
push hl ; --> lvl 1
ld hl, kbdScanCodes
ld hl, KBD_SHIFT_ON
bit 0, (hl)
ld hl, kbdScanCodes ; no flag changed
jr z, .shiftNotPressed
; Shift is being pressed. Use Shifted table.
ld hl, kbdScanCodesS
.shiftNotPressed:
call addHL
ld a, (hl)
pop hl ; <-- lvl 1
@ -57,13 +69,22 @@ kbdGetC:
; We have something!
cp a ; ensure Z
ret
.outOfBounds:
; A scan code over 0x80 is out of bounds. Ignore.
.shiftPressed:
ld a, 1
ld (KBD_SHIFT_ON), a
jr .ignore ; to actual char to return
.break:
ex af, af' ; restore saved KC
call .isShift
jr nz, .ignore
; We had a shift break, update status
xor a
jp unsetZ
.skip:
ld (KBD_SHIFT_ON), a
; continue to .ignore
.ignore:
; A scan code over 0x80 is out of bounds or prev KC tell us we should
; skip. Ignore.
xor a
ld (KBD_PREV_KC), a
jp unsetZ
.nothing:
; We have nothing. Before we go further, we'll wait a bit to give our
@ -77,6 +98,12 @@ kbdGetC:
djnz .wait
pop bc
jp unsetZ
; Whether KC in A is L or R shift
.isShift:
cp KBD_KC_LSHIFT
ret z
cp KBD_KC_RSHIFT
ret
; A list of the values associated with the 0x80 possible scan codes of the set
; 2 of the PS/2 keyboard specs. 0 means no value. That value is a character than
@ -98,3 +125,22 @@ kbdScanCodes:
.db 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0
; 0x70 27 = ESC
.db 0, 0, 0, 0, 0, 0, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0
; Same values, but shifted
kbdScanCodesS:
; 0x00 1 2 3 4 5 6 7 8 9 a b c d e f
.db 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9,'~', 0
; 0x10 9 = TAB
.db 0, 0, 0, 0, 0,'Q','!', 0, 0, 0,'Z','S','A','W','@', 0
; 0x20 32 = SPACE
.db 0,'C','X','D','E','$','#', 0, 0, 32,'V','F','T','R','%', 0
; 0x30
.db 0,'N','B','H','G','Y','^', 0, 0, 0,'M','J','U','&','*', 0
; 0x40 59 = ;
.db 0,'<','K','I','O',')','(', 0, 0,'>','?','L',':','P','_', 0
; 0x50 13 = RETURN 39 = '
.db 0, 0, 39, 0,'{','+', 0, 0, 0, 0, 13,'}', 0,'|', 0, 0
; 0x60 8 = BKSP
.db 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0
; 0x70 27 = ESC
.db 0, 0, 0, 0, 0, 0, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0