From 69429404abaf365ed649a2863830c1909f3626b2 Mon Sep 17 00:00:00 2001
From: Arnout Engelen <arnout@bzzt.net>
Date: Thu, 2 Jan 2025 10:47:12 +0100
Subject: [PATCH] tftpboot: explicitly mark phram as mappable

---
 modules/outputs/tftpboot.nix            |  1 +
 pkgs/kernel/default.nix                 |  5 ++---
 pkgs/kernel/phram-always-memremap.patch | 20 --------------------
 3 files changed, 3 insertions(+), 23 deletions(-)
 delete mode 100644 pkgs/kernel/phram-always-memremap.patch

diff --git a/modules/outputs/tftpboot.nix b/modules/outputs/tftpboot.nix
index 9c6d0389..f6f077a1 100644
--- a/modules/outputs/tftpboot.nix
+++ b/modules/outputs/tftpboot.nix
@@ -121,6 +121,7 @@ in {
             node=$(printf "phram-rootfs@%x" $rootfsStart)
             fdtput -p -t s dtb /reserved-memory/$node compatible phram
             fdtput -p -t lx dtb /reserved-memory/$node reg $ac_prefix $(hex $rootfsStart) $sz_prefix $(hex $rootfsSize)
+            fdtput -p -t i dtb /reserved-memory/$node no-map 0
 
             cmd="liminix ${cmdline} mtdparts=phram0:''${rootfsSize}(rootfs) phram.phram=phram0,''${rootfsStart},''${rootfsSize},${toString config.hardware.flash.eraseBlockSize} root=/dev/mtdblock0";
             fdtput -t s dtb /chosen ${config.boot.commandLineDtbNode} "$cmd"
diff --git a/pkgs/kernel/default.nix b/pkgs/kernel/default.nix
index 6662d5a1..9634127d 100644
--- a/pkgs/kernel/default.nix
+++ b/pkgs/kernel/default.nix
@@ -61,9 +61,8 @@ stdenv.mkDerivation rec {
   patches = [
     ./cmdline-cookie.patch
     ./mips-malta-fdt-from-bootloader.patch
-    ./phram-always-memremap.patch
-  ];# ++ lib.optional (lib.versionOlder version "5.18.0")
-    #./phram-allow-cached-mappings.patch
+  ] ++ lib.optional (lib.versionOlder version "5.18.0")
+    ./phram-allow-cached-mappings.patch;
 
   # this is here to work around what I think is a bug in nixpkgs
   # packaging of ncurses: it installs pkg-config data files which
diff --git a/pkgs/kernel/phram-always-memremap.patch b/pkgs/kernel/phram-always-memremap.patch
deleted file mode 100644
index 46b78e16..00000000
--- a/pkgs/kernel/phram-always-memremap.patch
+++ /dev/null
@@ -1,20 +0,0 @@
---- a/drivers/mtd/devices/phram.c	2024-12-20 23:42:19.248462526 +0100
-+++ b/drivers/mtd/devices/phram.c	2024-12-20 23:41:11.344218259 +0100
-@@ -85,7 +85,7 @@
- {
- 	void *addr = NULL;
- 
--	if (phram->cached)
-+	if (phram->cached || true)
- 		addr = memremap(start, len, MEMREMAP_WB);
- 	else
- 		addr = (void __force *)ioremap(start, len);
-@@ -101,7 +101,7 @@
- {
- 	void *addr = phram->mtd.priv;
- 
--	if (phram->cached) {
-+	if (phram->cached || true) {
- 		memunmap(addr);
- 		return;
- 	}