skl: add patch to pass entry point in %ebx

Done this way because things in SKL will change more drastically later
and there is no point in committing this.

Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>

recipes-support/skl/skl/0001-head-pass-entry-point-address-in-ebx-to-payload.patch

@@ -0,0 +1,25 @@
+From 4be25b0b35cf38d0dc3c3c6db674bfc36e6aa82f Mon Sep 17 00:00:00 2001
+From: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
+Date: Wed, 13 Nov 2024 19:30:48 +0200
+Subject: [PATCH] head: pass entry point address in %ebx to payload
+
+Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
+---
+ head.S | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/head.S b/head.S
+index 4c57eed..ba14ae4 100644
+--- a/head.S
++++ b/head.S
+@@ -246,7 +246,7 @@ GLOBAL(_entry)
+ 	 */
+ 	/* Linux expects Zero Page address in %esi, it is already there */
+ 	/* Multiboot2 expects MBI address in %ebx and magic number in %eax */
+-	mov	%esi, %ebx
++	mov	%edi, %ebx
+ 	mov	$MULTIBOOT2_BOOTLOADER_MAGIC, %eax
+ 	/* Simple payload expects argument on stack followed by return address */
+ 	push	%esi
+-- 
+2.47.0

recipes-support/skl/skl_git.bb

@@ -8,6 +8,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=4641e94ec96f98fabc56ff9cc48be14b"
 DEPENDS = "util-linux-native"
 
 SRC_URI = "git://github.com/TrenchBoot/secure-kernel-loader.git;protocol=https;branch=${BRANCH};name=skl"
+SRC_URI:append = " file://0001-head-pass-entry-point-address-in-ebx-to-payload.patch"
 BRANCH = "master"
 SRCREV = "1cc0a75191ed0309a6cc660533a8e044f40019d3"