qemu/hw/display/edid-generate.c
Gerd Hoffmann 40c503079f edid: prefer standard timings
Windows guests using the "Basic Display Adapter" don't parse the
"Established timings III" block.  They also don't parse any edid
extension.

So prefer the "Standard Timings" block to store the display resolutions
in edid_fill_modes().  Also reorder the mode list, so more exotic
resolutions (specifically the ones which are not supported by vgabios)
are moved down and the remaining ones have a better chance to get one of
the eight slots in the "Standard Timings" block.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210316143812.2363588-6-kraxel@redhat.com>
2021-03-23 12:37:13 +01:00

454 lines
11 KiB
C

/*
* QEMU EDID generator.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/bswap.h"
#include "hw/display/edid.h"
static const struct edid_mode {
uint32_t xres;
uint32_t yres;
uint32_t byte;
uint32_t xtra3;
uint32_t bit;
uint32_t dta;
} modes[] = {
/* dea/dta extension timings (all @ 50 Hz) */
{ .xres = 5120, .yres = 2160, .dta = 125 },
{ .xres = 4096, .yres = 2160, .dta = 101 },
{ .xres = 3840, .yres = 2160, .dta = 96 },
{ .xres = 2560, .yres = 1080, .dta = 89 },
{ .xres = 2048, .yres = 1152 },
{ .xres = 1920, .yres = 1080, .dta = 31 },
/* additional standard timings 3 (all @ 60Hz) */
{ .xres = 1920, .yres = 1200, .xtra3 = 10, .bit = 0 },
{ .xres = 1600, .yres = 1200, .xtra3 = 9, .bit = 2 },
{ .xres = 1680, .yres = 1050, .xtra3 = 9, .bit = 5 },
{ .xres = 1440, .yres = 900, .xtra3 = 8, .bit = 5 },
{ .xres = 1280, .yres = 1024, .xtra3 = 7, .bit = 1 },
{ .xres = 1280, .yres = 960, .xtra3 = 7, .bit = 3 },
{ .xres = 1280, .yres = 768, .xtra3 = 7, .bit = 6 },
{ .xres = 1920, .yres = 1440, .xtra3 = 11, .bit = 5 },
{ .xres = 1856, .yres = 1392, .xtra3 = 10, .bit = 3 },
{ .xres = 1792, .yres = 1344, .xtra3 = 10, .bit = 5 },
{ .xres = 1440, .yres = 1050, .xtra3 = 8, .bit = 1 },
{ .xres = 1360, .yres = 768, .xtra3 = 8, .bit = 7 },
/* established timings (all @ 60Hz) */
{ .xres = 1024, .yres = 768, .byte = 36, .bit = 3 },
{ .xres = 800, .yres = 600, .byte = 35, .bit = 0 },
{ .xres = 640, .yres = 480, .byte = 35, .bit = 5 },
};
static void edid_ext_dta(uint8_t *dta)
{
dta[0] = 0x02;
dta[1] = 0x03;
dta[2] = 0x05;
dta[3] = 0x00;
/* video data block */
dta[4] = 0x40;
}
static void edid_ext_dta_mode(uint8_t *dta, uint8_t nr)
{
dta[dta[2]] = nr;
dta[2]++;
dta[4]++;
}
static int edid_std_mode(uint8_t *mode, uint32_t xres, uint32_t yres)
{
uint32_t aspect;
if (xres == 0 || yres == 0) {
mode[0] = 0x01;
mode[1] = 0x01;
return 0;
} else if (xres * 10 == yres * 16) {
aspect = 0;
} else if (xres * 3 == yres * 4) {
aspect = 1;
} else if (xres * 4 == yres * 5) {
aspect = 2;
} else if (xres * 9 == yres * 16) {
aspect = 3;
} else {
return -1;
}
if ((xres / 8) - 31 > 255) {
return -1;
}
mode[0] = (xres / 8) - 31;
mode[1] = ((aspect << 6) | (60 - 60));
return 0;
}
static void edid_fill_modes(uint8_t *edid, uint8_t *xtra3, uint8_t *dta,
uint32_t maxx, uint32_t maxy)
{
const struct edid_mode *mode;
int std = 38;
int rc, i;
for (i = 0; i < ARRAY_SIZE(modes); i++) {
mode = modes + i;
if ((maxx && mode->xres > maxx) ||
(maxy && mode->yres > maxy)) {
continue;
}
if (mode->byte) {
edid[mode->byte] |= (1 << mode->bit);
} else if (std < 54) {
rc = edid_std_mode(edid + std, mode->xres, mode->yres);
if (rc == 0) {
std += 2;
}
} else if (mode->xtra3 && xtra3) {
xtra3[mode->xtra3] |= (1 << mode->bit);
}
if (dta && mode->dta) {
edid_ext_dta_mode(dta, mode->dta);
}
}
while (std < 54) {
edid_std_mode(edid + std, 0, 0);
std += 2;
}
}
static void edid_checksum(uint8_t *edid)
{
uint32_t sum = 0;
int i;
for (i = 0; i < 127; i++) {
sum += edid[i];
}
sum &= 0xff;
if (sum) {
edid[127] = 0x100 - sum;
}
}
static void edid_desc_type(uint8_t *desc, uint8_t type)
{
desc[0] = 0;
desc[1] = 0;
desc[2] = 0;
desc[3] = type;
desc[4] = 0;
}
static void edid_desc_text(uint8_t *desc, uint8_t type,
const char *text)
{
size_t len;
edid_desc_type(desc, type);
memset(desc + 5, ' ', 13);
len = strlen(text);
if (len > 12) {
len = 12;
}
memcpy(desc + 5, text, len);
desc[5 + len] = '\n';
}
static void edid_desc_ranges(uint8_t *desc)
{
edid_desc_type(desc, 0xfd);
/* vertical (50 -> 125 Hz) */
desc[5] = 50;
desc[6] = 125;
/* horizontal (30 -> 160 kHz) */
desc[7] = 30;
desc[8] = 160;
/* max dot clock (1200 MHz) */
desc[9] = 1200 / 10;
/* no extended timing information */
desc[10] = 0x01;
/* padding */
desc[11] = '\n';
memset(desc + 12, ' ', 6);
}
/* additional standard timings 3 */
static void edid_desc_xtra3_std(uint8_t *desc)
{
edid_desc_type(desc, 0xf7);
desc[5] = 10;
}
static void edid_desc_dummy(uint8_t *desc)
{
edid_desc_type(desc, 0x10);
}
static void edid_desc_timing(uint8_t *desc,
uint32_t xres, uint32_t yres,
uint32_t xmm, uint32_t ymm)
{
/* pull some realistic looking timings out of thin air */
uint32_t xfront = xres * 25 / 100;
uint32_t xsync = xres * 3 / 100;
uint32_t xblank = xres * 35 / 100;
uint32_t yfront = yres * 5 / 1000;
uint32_t ysync = yres * 5 / 1000;
uint32_t yblank = yres * 35 / 1000;
uint32_t clock = 75 * (xres + xblank) * (yres + yblank);
stl_le_p(desc, clock / 10000);
desc[2] = xres & 0xff;
desc[3] = xblank & 0xff;
desc[4] = (((xres & 0xf00) >> 4) |
((xblank & 0xf00) >> 8));
desc[5] = yres & 0xff;
desc[6] = yblank & 0xff;
desc[7] = (((yres & 0xf00) >> 4) |
((yblank & 0xf00) >> 8));
desc[8] = xfront & 0xff;
desc[9] = xsync & 0xff;
desc[10] = (((yfront & 0x00f) << 4) |
((ysync & 0x00f) << 0));
desc[11] = (((xfront & 0x300) >> 2) |
((xsync & 0x300) >> 4) |
((yfront & 0x030) >> 2) |
((ysync & 0x030) >> 4));
desc[12] = xmm & 0xff;
desc[13] = ymm & 0xff;
desc[14] = (((xmm & 0xf00) >> 4) |
((ymm & 0xf00) >> 8));
desc[17] = 0x18;
}
static uint32_t edid_to_10bit(float value)
{
return (uint32_t)(value * 1024 + 0.5);
}
static void edid_colorspace(uint8_t *edid,
float rx, float ry,
float gx, float gy,
float bx, float by,
float wx, float wy)
{
uint32_t red_x = edid_to_10bit(rx);
uint32_t red_y = edid_to_10bit(ry);
uint32_t green_x = edid_to_10bit(gx);
uint32_t green_y = edid_to_10bit(gy);
uint32_t blue_x = edid_to_10bit(bx);
uint32_t blue_y = edid_to_10bit(by);
uint32_t white_x = edid_to_10bit(wx);
uint32_t white_y = edid_to_10bit(wy);
edid[25] = (((red_x & 0x03) << 6) |
((red_y & 0x03) << 4) |
((green_x & 0x03) << 2) |
((green_y & 0x03) << 0));
edid[26] = (((blue_x & 0x03) << 6) |
((blue_y & 0x03) << 4) |
((white_x & 0x03) << 2) |
((white_y & 0x03) << 0));
edid[27] = red_x >> 2;
edid[28] = red_y >> 2;
edid[29] = green_x >> 2;
edid[30] = green_y >> 2;
edid[31] = blue_x >> 2;
edid[32] = blue_y >> 2;
edid[33] = white_x >> 2;
edid[34] = white_y >> 2;
}
static uint32_t qemu_edid_dpi_from_mm(uint32_t mm, uint32_t res)
{
return res * 254 / 10 / mm;
}
uint32_t qemu_edid_dpi_to_mm(uint32_t dpi, uint32_t res)
{
return res * 254 / 10 / dpi;
}
void qemu_edid_generate(uint8_t *edid, size_t size,
qemu_edid_info *info)
{
uint32_t desc = 54;
uint8_t *xtra3 = NULL;
uint8_t *dta = NULL;
uint32_t width_mm, height_mm;
uint32_t dpi = 100; /* if no width_mm/height_mm */
/* =============== set defaults =============== */
if (!info->vendor || strlen(info->vendor) != 3) {
info->vendor = "RHT";
}
if (!info->name) {
info->name = "QEMU Monitor";
}
if (!info->prefx) {
info->prefx = 1024;
}
if (!info->prefy) {
info->prefy = 768;
}
if (info->width_mm && info->height_mm) {
width_mm = info->width_mm;
height_mm = info->height_mm;
dpi = qemu_edid_dpi_from_mm(width_mm, info->prefx);
} else {
width_mm = qemu_edid_dpi_to_mm(dpi, info->prefx);
height_mm = qemu_edid_dpi_to_mm(dpi, info->prefy);
}
/* =============== extensions =============== */
if (size >= 256) {
dta = edid + 128;
edid[126]++;
edid_ext_dta(dta);
}
/* =============== header information =============== */
/* fixed */
edid[0] = 0x00;
edid[1] = 0xff;
edid[2] = 0xff;
edid[3] = 0xff;
edid[4] = 0xff;
edid[5] = 0xff;
edid[6] = 0xff;
edid[7] = 0x00;
/* manufacturer id, product code, serial number */
uint16_t vendor_id = ((((info->vendor[0] - '@') & 0x1f) << 10) |
(((info->vendor[1] - '@') & 0x1f) << 5) |
(((info->vendor[2] - '@') & 0x1f) << 0));
uint16_t model_nr = 0x1234;
uint32_t serial_nr = info->serial ? atoi(info->serial) : 0;
stw_be_p(edid + 8, vendor_id);
stw_le_p(edid + 10, model_nr);
stl_le_p(edid + 12, serial_nr);
/* manufacture week and year */
edid[16] = 42;
edid[17] = 2014 - 1990;
/* edid version */
edid[18] = 1;
edid[19] = 4;
/* =============== basic display parameters =============== */
/* video input: digital, 8bpc, displayport */
edid[20] = 0xa5;
/* screen size: undefined */
edid[21] = width_mm / 10;
edid[22] = height_mm / 10;
/* display gamma: 2.2 */
edid[23] = 220 - 100;
/* supported features bitmap: std sRGB, preferred timing */
edid[24] = 0x06;
/* =============== chromaticity coordinates =============== */
/* standard sRGB colorspace */
edid_colorspace(edid,
0.6400, 0.3300, /* red */
0.3000, 0.6000, /* green */
0.1500, 0.0600, /* blue */
0.3127, 0.3290); /* white point */
/* =============== established timing bitmap =============== */
/* =============== standard timing information =============== */
/* both filled by edid_fill_modes() */
/* =============== descriptor blocks =============== */
edid_desc_timing(edid + desc, info->prefx, info->prefy,
width_mm, height_mm);
desc += 18;
edid_desc_ranges(edid + desc);
desc += 18;
if (info->name) {
edid_desc_text(edid + desc, 0xfc, info->name);
desc += 18;
}
if (info->serial) {
edid_desc_text(edid + desc, 0xff, info->serial);
desc += 18;
}
if (desc < 126) {
xtra3 = edid + desc;
edid_desc_xtra3_std(xtra3);
desc += 18;
}
while (desc < 126) {
edid_desc_dummy(edid + desc);
desc += 18;
}
/* =============== finish up =============== */
edid_fill_modes(edid, xtra3, dta, info->maxx, info->maxy);
edid_checksum(edid);
if (dta) {
edid_checksum(dta);
}
}
size_t qemu_edid_size(uint8_t *edid)
{
uint32_t exts;
if (edid[0] != 0x00 ||
edid[1] != 0xff) {
/* doesn't look like a valid edid block */
return 0;
}
exts = edid[126];
return 128 * (exts + 1);
}