From aedb3533de153d927dcb95a4b8be8d4574431a50 Mon Sep 17 00:00:00 2001
From: Roland Coeurjoly <rolandcoeurjoly@gmail.com>
Date: Fri, 22 May 2026 19:46:37 +0200
Subject: [PATCH] Add patch for PrjxrayDb

---
 flake.lock |  4 ++++
 flake.nix  | 48 ++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/flake.lock b/flake.lock
index ea01b97..9bf593e 100644
--- a/flake.lock
+++ b/flake.lock
@@ -54,6 +54,10 @@
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "toolchain-nix",
+          "nixpkgs"
+        ],
         "toolchain-nix": "toolchain-nix"
       }
     },
diff --git a/flake.nix b/flake.nix
index 297a413..fe565b4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -4,10 +4,50 @@
   inputs = {
     flake-utils.url = "github:numtide/flake-utils";
     toolchain-nix.url = "github:openXC7/toolchain-nix";
+    nixpkgs.follows = "toolchain-nix/nixpkgs";
   };
 
-  outputs = { flake-utils, toolchain-nix, ... }:
-    flake-utils.lib.eachDefaultSystem (system: {
-      devShells.default = toolchain-nix.devShell.${system};
-    });
+  outputs = { flake-utils, nixpkgs, toolchain-nix, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        openXc7Shell = toolchain-nix.devShell.${system};
+        nextpnrXilinx = toolchain-nix.packages.${system}.nextpnr-xilinx;
+        originalPrjxrayDb = "${nextpnrXilinx}/share/nextpnr/external/prjxray-db";
+        patchedPrjxrayDb = pkgs.runCommand "prjxray-db-kintex7-lioi3-tbytesrc-oclkm-overlay" { } ''
+          mkdir -p $out
+          cp -a ${originalPrjxrayDb}/kintex7 $out/kintex7
+
+          for db_file in \
+            $out/kintex7/segbits_lioi3_tbytesrc.db \
+            $out/kintex7/segbits_lioi3_tbytesrc.origin_info.db
+          do
+            chmod u+w "$db_file"
+          done
+
+          if ! grep -q "^LIOI3_TBYTESRC.IOI_OCLKM_0.IOI_IMUX31_1 " \
+            $out/kintex7/segbits_lioi3_tbytesrc.db
+          then
+            cat >> $out/kintex7/segbits_lioi3_tbytesrc.db <<EOF
+LIOI3_TBYTESRC.IOI_OCLKM_0.IOI_IMUX31_1 30_94 31_83 31_93
+EOF
+          fi
+
+          if ! grep -q "^LIOI3_TBYTESRC.IOI_OCLKM_0.IOI_IMUX31_1 " \
+            $out/kintex7/segbits_lioi3_tbytesrc.origin_info.db
+          then
+            cat >> $out/kintex7/segbits_lioi3_tbytesrc.origin_info.db <<EOF
+LIOI3_TBYTESRC.IOI_OCLKM_0.IOI_IMUX31_1 origin:037-iob-pips 30_94 31_83 31_93
+EOF
+          fi
+        '';
+      in {
+        devShells.default = pkgs.mkShell {
+          inputsFrom = [ openXc7Shell ];
+          shellHook = ''
+            ${openXc7Shell.shellHook or ""}
+            export PRJXRAY_DB_DIR="${patchedPrjxrayDb}"
+          '';
+        };
+      });
 }