Bare metal VGA: minor improvements (#608)

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tkchia 2022-09-10 19:28:28 +08:00 committed by GitHub
parent 155b378a39
commit bae7367774
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 79 additions and 101 deletions

View file

@ -93,7 +93,7 @@ static wchar_t *Wcs(struct Tty *tty)
void _StartTty(struct Tty *tty, unsigned short yn, unsigned short xn,
unsigned short starty, unsigned short startx,
void *vccs, wchar_t *wcs) {
unsigned char chr_ht, void *vccs, wchar_t *wcs) {
struct VgaTextCharCell *ccs = vccs;
memset(tty, 0, sizeof(struct Tty));
SetYn(tty, yn);
@ -103,8 +103,11 @@ void _StartTty(struct Tty *tty, unsigned short yn, unsigned short xn,
starty = yn - 1;
if (startx >= xn)
startx = xn - 1;
if (chr_ht > 32)
chr_ht = 32;
tty->y = starty;
tty->x = startx;
tty->chr_ht = chr_ht;
if (SetWcs(tty, wcs)) {
size_t n = (size_t)yn * xn, i;
for (i = 0; i < n; ++i)
@ -143,66 +146,27 @@ static wchar_t *GetXlatLineDrawing(void) {
return xlat;
}
static void XlatAlphabet(wchar_t xlat[128], int a, int b) {
unsigned i;
for (i = 0; i < 128; ++i) {
if ('a' <= i && i <= 'z') {
xlat[i] = i - 'a' + a;
} else if ('A' <= i && i <= 'Z') {
xlat[i] = i - 'A' + b;
} else {
xlat[i] = i;
}
}
}
static wchar_t *GetXlatItalic(void) {
static bool once;
static wchar_t xlat[128];
if (!once) {
XlatAlphabet(xlat, L'𝑎', L'𝐴');
once = true;
}
return xlat;
/* Unimplemented. Simply output normal non-italicized characters for now. */
return GetXlatAscii();
}
static wchar_t *GetXlatBoldItalic(void) {
static bool once;
static wchar_t xlat[128];
if (!once) {
XlatAlphabet(xlat, L'𝒂', L'𝑨');
once = true;
}
return xlat;
/*
* Unimplemented. Simply output high-intensity non-italicized characters
* for now.
*/
return GetXlatAscii();
}
static wchar_t *GetXlatBoldFraktur(void) {
static bool once;
static wchar_t xlat[128];
if (!once) {
XlatAlphabet(xlat, L'𝖆', L'𝕬');
once = true;
}
return xlat;
/* Unimplemented. */
return GetXlatAscii();
}
static wchar_t *GetXlatFraktur(void) {
unsigned i;
static bool once;
static wchar_t xlat[128];
if (!once) {
for (i = 0; i < ARRAYLEN(xlat); ++i) {
if ('A' <= i && i <= 'Z') {
xlat[i] = L"𝔄𝔅𝔇𝔈𝔉𝔊𝔍𝔎𝔏𝔐𝔑𝔒𝔓𝔔𝔖𝔗𝔘𝔙𝔚𝔛𝔜"[i - 'A'];
} else if ('a' <= i && i <= 'z') {
xlat[i] = i - 'a' + L'𝔞';
} else {
xlat[i] = i;
}
}
once = true;
}
return xlat;
/* Unimplemented. */
return GetXlatAscii();
}
static wchar_t *GetXlatDoubleWidth(void) {
@ -258,15 +222,33 @@ static void TtySetCodepage(struct Tty *tty, char id) {
}
}
/**
* Map the currently active foreground & background colors & terminal
* configuration to a VGA text character attribute byte.
*
* @see VGA_USE_BLINK macro (libc/vga/vga.internal.h)
* @see drivers/tty/vt/vt.c in Linux 5.9.14 source code
*/
static uint8_t TtyGetVgaAttr(struct Tty *tty)
{
uint8_t attr = tty->fg | tty->bg << 4;
if ((tty->pr & kTtyBold) != 0)
attr |= 0x08;
uint8_t attr;
if ((tty->pr & kTtyFlip) == 0)
attr = tty->fg | tty->bg << 4;
else
attr = tty->bg | tty->fg << 4;
#ifdef VGA_USE_BLINK
/*
* If blinking is enabled, we can only have the 8 dark background color
* codes (0 to 7). Simply map any bright background color (8 to 15) to
* its corresponding dark color, & call it a day. This is a bit more
* simplistic than what Linux does, but should be enough.
*/
attr &= ~0x80;
if ((tty->pr & kTtyBlink) != 0)
attr |= 0x80;
#endif
if ((tty->pr & kTtyBold) != 0)
attr |= 0x08;
return attr;
}
@ -639,37 +621,23 @@ static void TtyCsiN(struct Tty *tty) {
/**
* Map the given (R, G, B) triplet to one of the 16 basic foreground colors
* or one of the 8 (or 16) background colors.
* or one of the 16 background colors.
*
* @see VGA_USE_BLINK macro (libc/vga/vga.internal.h)
* @see drivers/tty/vt/vt.c in Linux 5.9.14 source code
*/
static uint8_t TtyMapTrueColor(uint8_t r, uint8_t g, uint8_t b, bool as_fg)
static uint8_t TtyMapTrueColor(uint8_t r, uint8_t g, uint8_t b)
{
uint8_t hue = 0;
#ifdef VGA_USE_BLINK
if (!as_fg) {
if (r >= 128)
hue |= 4;
if (g >= 128)
hue |= 2;
if (b >= 128)
hue |= 1;
} else
#endif
{
uint8_t max = MAX(MAX(r, g), b);
if (r > max / 2)
hue |= 4;
if (g > max / 2)
hue |= 2;
if (b > max / 2)
hue |= 1;
if (hue == 7 && max <= 0x55)
hue = 8;
else if (max > 0xaa)
hue |= 8;
}
uint8_t hue = 0, max = MAX(MAX(r, g), b);
if (r > max / 2)
hue |= 4;
if (g > max / 2)
hue |= 2;
if (b > max / 2)
hue |= 1;
if (hue == 7 && max <= 0x55)
hue = 8;
else if (max > 0xaa)
hue |= 8;
return hue;
}
@ -679,7 +647,7 @@ static uint8_t TtyMapTrueColor(uint8_t r, uint8_t g, uint8_t b, bool as_fg)
*
* @see drivers/tty/vt/vt.c in Linux 5.9.14 source code
*/
static uint8_t TtyMapXtermColor(uint8_t color, bool as_fg)
static uint8_t TtyMapXtermColor(uint8_t color)
{
uint8_t r, g, b;
if (color < 8) {
@ -699,7 +667,7 @@ static uint8_t TtyMapXtermColor(uint8_t color, bool as_fg)
r = color * 0x55 / 2;
} else
r = g = b = (unsigned)color * 10 - 2312;
return TtyMapTrueColor(r, g, b, as_fg);
return TtyMapTrueColor(r, g, b);
}
static void TtySelectGraphicsRendition(struct Tty *tty) {
@ -822,13 +790,7 @@ static void TtySelectGraphicsRendition(struct Tty *tty) {
break;
case 100 ... 107:
code[0] -= 100 - 40;
#ifndef VGA_USE_BLINK
/*
* If blinking is not enabled in VGA text mode, then we can
* use bright background colors.
*/
code[0] += 8;
#endif
/* fallthrough */
case 40 ... 47:
tty->bg = code[0] - 40;
@ -855,7 +817,7 @@ static void TtySelectGraphicsRendition(struct Tty *tty) {
if (++code[3] == 3) {
code[3] = 0;
t = kSgr;
tty->fg = TtyMapTrueColor(code[0], code[1], code[2], true);
tty->fg = TtyMapTrueColor(code[0], code[1], code[2]);
tty->pr |= kTtyFg;
tty->pr |= kTtyTrue;
}
@ -864,20 +826,20 @@ static void TtySelectGraphicsRendition(struct Tty *tty) {
if (++code[3] == 3) {
code[3] = 0;
t = kSgr;
tty->bg = TtyMapTrueColor(code[0], code[1], code[2], false);
tty->bg = TtyMapTrueColor(code[0], code[1], code[2]);
tty->pr |= kTtyBg;
tty->pr |= kTtyTrue;
}
break;
case kSgrFgXterm:
t = kSgr;
tty->fg = TtyMapXtermColor(code[0], true);
tty->fg = TtyMapXtermColor(code[0]);
tty->pr |= kTtyFg;
tty->pr &= ~kTtyTrue;
break;
case kSgrBgXterm:
t = kSgr;
tty->bg = TtyMapXtermColor(code[0], false);
tty->bg = TtyMapXtermColor(code[0]);
tty->pr |= kTtyBg;
tty->pr &= ~kTtyTrue;
break;
@ -1081,10 +1043,17 @@ static void TtyEscAppend(struct Tty *tty, char c) {
}
static void TtyUpdateHwCursor(struct Tty *tty) {
unsigned char start = tty->chr_ht - 2, end = tty->chr_ht - 1;
unsigned short pos = tty->y * Xn(tty) + tty->x;
outb(CRTPORT, 0x0e);
if ((tty->conf & kTtyNocursor))
start |= 1 << 5;
outb(CRTPORT, 0x0A);
outb(CRTPORT + 1, start);
outb(CRTPORT, 0x0B);
outb(CRTPORT + 1, end);
outb(CRTPORT, 0x0E);
outb(CRTPORT + 1, (unsigned char)(pos >> 8));
outb(CRTPORT, 0x0f);
outb(CRTPORT, 0x0F);
outb(CRTPORT + 1, (unsigned char)pos);
}

View file

@ -109,7 +109,7 @@ struct Tty {
uint32_t u8;
uint32_t n8;
uint32_t pr;
uint8_t fg, bg;
uint8_t fg, bg, chr_ht;
uint32_t conf;
unsigned short savey, savex;
struct VgaTextCharCell *ccs;
@ -134,7 +134,8 @@ struct Tty {
};
void _StartTty(struct Tty *, unsigned short, unsigned short,
unsigned short, unsigned short, void *, wchar_t *);
unsigned short, unsigned short, unsigned char,
void *, wchar_t *);
ssize_t _TtyRead(struct Tty *, void *, size_t);
ssize_t _TtyWrite(struct Tty *, const void *, size_t);
ssize_t _TtyWriteInput(struct Tty *, const void *, size_t);

View file

@ -58,15 +58,23 @@ ssize_t sys_writev_vga(struct Fd *fd, const struct iovec *iov, int iovlen) {
__attribute__((__constructor__)) static textstartup void _vga_init(void) {
void * const vid_buf = (void *)(BANE + 0xb8000ull);
/* Get the initial cursor position from the BIOS data area. */
/*
* Get the initial cursor position from the BIOS data area. Also get
* the height (in scan lines) of each character; this is used to set the
* cursor shape.
*/
typedef struct {
unsigned char col, row;
} bios_curs_pos_t;
bios_curs_pos_t pos = *(bios_curs_pos_t *)(BANE + 0x0450ull);
uint8_t chr_ht = *(uint8_t *)(BANE + 0x0485ull),
chr_ht_hi = *(uint8_t *)(BANE + 0x0486ull);
if (chr_ht_hi != 0 || chr_ht > 32)
chr_ht = 32;
/*
* Initialize our tty structure from the current screen contents & current
* cursor position.
* Initialize our tty structure from the current screen contents, current
* cursor position, & character height.
*/
_StartTty(&vga_tty, VGA_TTY_HEIGHT, VGA_TTY_WIDTH, pos.row, pos.col,
vid_buf, vga_wcs);
chr_ht, vid_buf, vga_wcs);
}