From 74e3c83bedab54114aa3f48994b53e57f4b472da Mon Sep 17 00:00:00 2001
From: Cacodemon345 <wahil1976@outlook.com>
Date: Tue, 26 Aug 2025 01:42:59 +0600
Subject: [PATCH] Custom EDIDs

---
 src/86box.c                 |  3 ++
 src/config.c                | 14 ++++++++++
 src/include/86box/86box.h   |  3 ++
 src/include/86box/vid_ddc.h |  1 +
 src/video/vid_ddc.c         | 56 +++++++++++++++++++++++++++++++++++--
 5 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/src/86box.c b/src/86box.c
index 498c86871..7b67e3ba9 100644
--- a/src/86box.c
+++ b/src/86box.c
@@ -231,6 +231,9 @@ int      is_pcjr = 0;                                             /* The current
 int      portable_mode = 0;                                       /* We are running in portable mode
                                                                      (global dirs = exe path) */
 
+int      monitor_edid = 0;                                        /* (C) Which EDID to use. 0=default, 1=custom. */
+char     monitor_edid_path[1024] = { 0 };                         /* (C) Path to custom EDID */
+
 // Accelerator key array
 struct accelKey acc_keys[NUM_ACCELS];
 
diff --git a/src/config.c b/src/config.c
index e88a4753e..af3f39cb8 100644
--- a/src/config.c
+++ b/src/config.c
@@ -501,6 +501,11 @@ load_video(void)
             p = "none";
         gfxcard[i] = video_get_video_from_internal_name(p);
     }
+
+    monitor_edid = ini_section_get_int(cat, "monitor_edid", 0);
+
+    monitor_edid_path[0] = 0;
+    strncpy(monitor_edid_path, ini_section_get_string(cat, "monitor_edid_path", (char*)""), sizeof(monitor_edid_path));
 }
 
 /* Load "Input Devices" section. */
@@ -2487,6 +2492,15 @@ save_video(void)
     ini_section_set_string(cat, "gfxcard",
                            video_get_internal_name(gfxcard[0]));
 
+    if (monitor_edid)
+        ini_section_set_int(cat, "monitor_edid", monitor_edid);
+    else
+        ini_section_delete_var(cat, "monitor_edid");
+
+    if (monitor_edid_path[0])
+        ini_section_set_string(cat, "monitor_edid_path", monitor_edid_path);
+    else
+        ini_section_delete_var(cat, "monitor_edid_path");
 
     if (vid_cga_comp_brightness)
         ini_section_set_int(cat, "vid_cga_comp_brightness", vid_cga_comp_brightness);
diff --git a/src/include/86box/86box.h b/src/include/86box/86box.h
index 521e50965..8696cbabd 100644
--- a/src/include/86box/86box.h
+++ b/src/include/86box/86box.h
@@ -201,6 +201,9 @@ extern int  start_vmm;             /* the current execution will start the manag
 extern int  portable_mode;         /* we are running in portable mode 
                                       (global dirs = exe path) */
 
+extern int  monitor_edid;                   /* (C) Which EDID to use. 0=default, 1=custom. */
+extern char monitor_edid_path[1024];        /* (C) Path to custom EDID */
+
 #ifndef USE_NEW_DYNAREC
 extern FILE *stdlog; /* file to log output to */
 #endif
diff --git a/src/include/86box/vid_ddc.h b/src/include/86box/vid_ddc.h
index 144cca406..8d68d0adf 100644
--- a/src/include/86box/vid_ddc.h
+++ b/src/include/86box/vid_ddc.h
@@ -22,5 +22,6 @@
 
 extern void *ddc_init(void *i2c);
 extern void  ddc_close(void *eeprom);
+extern void *ddc_create_default_edid(ssize_t* size_out);
 
 #endif /*EMU_VID_DDC_H*/
diff --git a/src/video/vid_ddc.c b/src/video/vid_ddc.c
index 787e7560e..2d1b78c0d 100644
--- a/src/video/vid_ddc.c
+++ b/src/video/vid_ddc.c
@@ -23,6 +23,8 @@
 #include <math.h>
 #include <86box/86box.h>
 #include <86box/i2c.h>
+#include <86box/vid_ddc.h>
+#include <86box/plat.h>
 
 #define PIXEL_MM(px) (((px) * 25.4) / 96.0)
 #define STANDARD_TIMING(slot, width, aspect_ratio, refresh)                             \
@@ -126,8 +128,8 @@ typedef struct {
     uint8_t padding[15], checksum2;
 } edid_t;
 
-void *
-ddc_init(void *i2c)
+void*
+ddc_create_default_edid(ssize_t* size_out)
 {
     edid_t *edid = malloc(sizeof(edid_t));
     memset(edid, 0, sizeof(edid_t));
@@ -222,7 +224,55 @@ ddc_init(void *i2c)
         edid->checksum2 += edid_bytes[c];
     edid->checksum2 = 256 - edid->checksum2;
 
-    return i2c_eeprom_init(i2c, 0x50, edid_bytes, sizeof(edid_t), 0);
+    if (size_out)
+        *size_out = sizeof(edid_t);
+    
+    return edid;
+}
+
+void *
+ddc_init(void *i2c)
+{
+    ssize_t edid_size = 0;
+    void* edid_bytes = NULL;
+    if (monitor_edid == 1 && monitor_edid_path[0]) {
+        FILE* file = plat_fopen(monitor_edid_path, "rb");
+
+        if (!file)
+            goto default_init;
+
+        if (fseek(file, 0, SEEK_END) == -1) {
+            fclose(file);
+            goto default_init;
+        }
+
+        edid_size = ftell(file);
+        fseek(file, 0, SEEK_SET);
+
+        if (edid_size <= 0) {
+            fclose(file);
+            goto default_init;
+        }
+
+        edid_bytes = calloc(1, edid_size);
+        if (!edid_bytes) {
+            fclose(file);
+            goto default_init;
+        }
+
+        if (fread(edid_bytes, edid_size, 1, file) <= 0) {
+            free(edid_bytes);
+            fclose(file);
+            goto default_init;
+        }
+
+        fclose(file);
+        return i2c_eeprom_init(i2c, 0x50, edid_bytes, edid_size, 0);
+    }
+default_init:
+    edid_size = sizeof(edid_t);
+    edid_bytes = ddc_create_default_edid(&edid_size);
+    return i2c_eeprom_init(i2c, 0x50, edid_bytes, edid_size, 0);
 }
 
 void