qemu/hw/display/edid-generate.c
Anton V. Boyarshinov cd8fef8d4b Arithmetic error in EDID generation fixed
To calculate screen size in centimeters we should calculate:
pixels/dpi*2.54
but not
pixels*dpi/2540

Using wrong formula we actually get 65 DPI and very small fonts.

Signed-off-by: Anton V. Boyarshinov <boyarsh@altlinux.org>
Message-id: 20200226122054.366b9cda@table.localdomain
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2020-03-02 08:20:30 +01:00

439 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 = 1440, .xtra3 = 11, .bit = 5 },
{ .xres = 1920, .yres = 1200, .xtra3 = 10, .bit = 0 },
{ .xres = 1856, .yres = 1392, .xtra3 = 10, .bit = 3 },
{ .xres = 1792, .yres = 1344, .xtra3 = 10, .bit = 5 },
{ .xres = 1600, .yres = 1200, .xtra3 = 9, .bit = 2 },
{ .xres = 1680, .yres = 1050, .xtra3 = 9, .bit = 5 },
{ .xres = 1440, .yres = 1050, .xtra3 = 8, .bit = 1 },
{ .xres = 1440, .yres = 900, .xtra3 = 8, .bit = 5 },
{ .xres = 1360, .yres = 768, .xtra3 = 8, .bit = 7 },
{ .xres = 1280, .yres = 1024, .xtra3 = 7, .bit = 1 },
{ .xres = 1280, .yres = 960, .xtra3 = 7, .bit = 3 },
{ .xres = 1280, .yres = 768, .xtra3 = 7, .bit = 6 },
/* 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 (mode->xtra3 && xtra3) {
xtra3[mode->xtra3] |= (1 << mode->bit);
} else if (std < 54) {
rc = edid_std_mode(edid + std, mode->xres, mode->yres);
if (rc == 0) {
std += 2;
}
}
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 dpi)
{
/* physical display size */
uint32_t xmm = xres * dpi / 254;
uint32_t ymm = yres * dpi / 254;
/* 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;
}
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;
/* =============== set defaults =============== */
if (!info->vendor || strlen(info->vendor) != 3) {
info->vendor = "RHT";
}
if (!info->name) {
info->name = "QEMU Monitor";
}
if (!info->dpi) {
info->dpi = 100;
}
if (!info->prefx) {
info->prefx = 1024;
}
if (!info->prefy) {
info->prefy = 768;
}
/* =============== 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] = info->prefx * 254 / 100 / info->dpi;
edid[22] = info->prefy * 254 / 100 / info->dpi;
/* 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, info->dpi);
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);
}