Qemu patch to allow generating EDID information for 5k resolution

qemu-edid-5k.diff

diff --git a/hw/display/edid-generate.c b/hw/display/edid-generate.c
index b0ce583d436..9941fd59aab 100644
--- a/hw/display/edid-generate.c
+++ b/hw/display/edid-generate.c
@@ -129,17 +129,17 @@ static void edid_fill_modes(uint8_t *edid, uint8_t *xtra3, uint8_t *dta,
     }
 }
 
-static void edid_checksum(uint8_t *edid)
+static void edid_checksum(uint8_t *edid, size_t len)
 {
     uint32_t sum = 0;
     int i;
 
-    for (i = 0; i < 127; i++) {
+    for (i = 0; i < len; i++) {
         sum += edid[i];
     }
     sum &= 0xff;
     if (sum) {
-        edid[127] = 0x100 - sum;
+        edid[len] = 0x100 - sum;
     }
 }
 
@@ -296,12 +296,60 @@ uint32_t qemu_edid_dpi_to_mm(uint32_t dpi, uint32_t res)
     return res * 254 / 10 / dpi;
 }
 
+static void qemu_displayid_generate(uint8_t* did, uint32_t refresh_rate,
+                                    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;
+
+    uint64_t clock  = ((uint64_t)refresh_rate * (xres + xblank) * (yres + yblank)) / 10000000;
+
+    did[0] = 0x70; // display id extension
+    did[1] = 0x13; // version 1.3
+    did[2] = 23; // length
+    did[3] = 0x03; // product type (0x03 == standalone display device)
+
+    uint32_t offset = 5;
+
+    did[offset] = 0x03; //Detailed Timings Data Block
+    did[offset+1] = 0x00; // revision
+    did[offset+2] = 0x14; // block length
+
+    uint32_t block = offset + 3;
+
+    did[block] = clock & 0xff;
+    did[block+1] = (clock & 0xff00) >> 8;
+    did[block+2] = (clock & 0xff0000) >> 16;
+
+    did[block+3] = 0x88;
+
+    stw_le_p(did + block+4, 0xffff & (xres-1));
+    stw_le_p(did + block+6, 0xffff & (xblank-1));
+    stw_le_p(did + block+8, 0xffff & (xfront-1));
+    stw_le_p(did + block+10, 0xffff & (xsync-1));
+
+    stw_le_p(did + block+12, 0xffff & (yres-1));
+    stw_le_p(did + block+14, 0xffff & (yblank-1));
+    stw_le_p(did + block+16, 0xffff & (yfront-1));
+    stw_le_p(did + block+18, 0xffff & (ysync-1));
+
+    edid_checksum(did + 1, did[2] + 4);
+}
+
 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;
+    uint8_t *did = NULL;
     uint32_t width_mm, height_mm;
     uint32_t refresh_rate = info->refresh_rate ? info->refresh_rate : 75000;
     uint32_t dpi = 100; /* if no width_mm/height_mm */
@@ -429,13 +477,28 @@ void qemu_edid_generate(uint8_t *edid, size_t size,
         desc += 18;
     }
 
+    /* =============== dislpay id extensions =============== */
+
+    if (size >= 384) {
+        did = edid + 256;
+        edid[126]++;
+
+        qemu_displayid_generate(did, refresh_rate, info->prefx, info->prefy,
+                                width_mm, height_mm);
+    }
+
+
     /* =============== finish up =============== */
 
     edid_fill_modes(edid, xtra3, dta, info->maxx, info->maxy);
-    edid_checksum(edid);
+    edid_checksum(edid, 127);
     if (dta) {
-        edid_checksum(dta);
+        edid_checksum(dta, 127);
+    }
+    if (did) {
+        edid_checksum(did, 127);
     }
+
 }
 
 size_t qemu_edid_size(uint8_t *edid)
diff --git a/hw/display/vga-pci.c b/hw/display/vga-pci.c
index 48d29630ab7..62fb5c38c1f 100644
--- a/hw/display/vga-pci.c
+++ b/hw/display/vga-pci.c
@@ -49,7 +49,7 @@ struct PCIVGAState {
     qemu_edid_info edid_info;
     MemoryRegion mmio;
     MemoryRegion mrs[4];
-    uint8_t edid[256];
+    uint8_t edid[384];
 };
 
 #define TYPE_PCI_VGA "pci-vga"
diff --git a/qemu-edid.c b/qemu-edid.c
index 1cd6a951723..028f2d181a1 100644
--- a/qemu-edid.c
+++ b/qemu-edid.c
@@ -41,7 +41,7 @@ static void usage(FILE *out)
 int main(int argc, char *argv[])
 {
     FILE *outfile = NULL;
-    uint8_t blob[256];
+    uint8_t blob[384];
     uint32_t dpi = 100;
     int rc;