From dbf1ecdcb7d55a187c76962e048356d3267b03a0 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Sat, 23 Dec 2023 15:34:01 +0000
Subject: [PATCH] swap zimage and dtb in ram

kernel uncompression code creates a stack directly
after the compressed payload, which was trashing the dtb
---
 modules/outputs/tftpboot.nix | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/modules/outputs/tftpboot.nix b/modules/outputs/tftpboot.nix
index 927efe9..cd2cd1b 100644
--- a/modules/outputs/tftpboot.nix
+++ b/modules/outputs/tftpboot.nix
@@ -72,18 +72,19 @@ in {
             hex() { printf "0x%x" $1; }
             rootfsStart=${toString cfg.loadAddress}
             rootfsSize=$(binsize64k ${o.rootfs} )
-            imageStart=$(($rootfsStart + $rootfsSize))
-            imageSize=$(binsize ${image})
-            dtbStart=$(($imageStart + $imageSize))
+            dtbStart=$(($rootfsStart + $rootfsSize))
             dtbSize=$(binsize ${o.dtb} )
+            imageStart=$(($dtbStart + $dtbSize))
+            imageSize=$(binsize ${image})
 
             ln -s ${o.manifest} manifest
             ln -s ${image} image
+            ln -s ${o.kernel} vmlinux  # handy for gdb
 
             ${if cfg.compressRoot
               then ''
                 lzma -z9cv ${o.rootfs} > rootfs.lz
-                rootfsLzStart=$(($dtbStart + $dtbSize))
+                rootfsLzStart=$(($imageStart + $imageSize))
                 rootfsLzSize=$(binsize rootfs.lz)
               ''
               else "ln -s ${o.rootfs} rootfs"