From b5d93b9b73398f325eef8ae0b6fc2c75ac0b7f93 Mon Sep 17 00:00:00 2001
From: quackerd <d@quacker.org>
Date: Mon, 21 Oct 2024 07:21:56 -0400
Subject: [PATCH] handle dtb size

---
 sys/arm64/locore.S  | 13 ++++++++-----
 sys/arm64/mbentry.c | 17 ++++++++++++++---
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/sys/arm64/locore.S b/sys/arm64/locore.S
index 26ad7a9..6c9dcc3 100644
--- a/sys/arm64/locore.S
+++ b/sys/arm64/locore.S
@@ -25,9 +25,10 @@ _bootstack:
 .globl _start
 _start:
 .extern _evt
-    // save x0, x1 to x13, x14
+    // save x0, x1, x2 to x13, x14, x15
     mov x13, x0
     mov x14, x1
+    mov x15, x2
 
     // setup EVT for all levels (before MMU)
     ldr x0,=LOWMEM(_evt)
@@ -162,11 +163,13 @@ _high_addr:
 // re-setup el1 EVT with high addr
     ldr x0, =_evt
     msr VBAR_EL1, x0
-.extern MachineBoot_Entry
-    ldr x15, =MachineBoot_Entry
-    mov x0, x13 // restore magic & dtb load addr
+    mov x0, x13 // restore magic & dtb load addr + size
     mov x1, x14
-    blr x15
+    mov x2, x15
+
+.extern MachineBoot_Entry
+    ldr x9, =MachineBoot_Entry
+    blr x9
     b _halt
 
 .global _halt
diff --git a/sys/arm64/mbentry.c b/sys/arm64/mbentry.c
index c171542..006af35 100644
--- a/sys/arm64/mbentry.c
+++ b/sys/arm64/mbentry.c
@@ -16,8 +16,6 @@
 
 #include <sys/contrib/libfdt/libfdt.h>
 
-void MachineBoot_Entry(unsigned long magic, unsigned long addr);
-
 #define PAGE_ALIGN __attribute__((aligned(PGSIZE)))
 #define DATA_SECTION __attribute__((section(".data")))
 
@@ -41,12 +39,25 @@ machineboot_init_mem_regions()
 	memRegionIdx = 1;
 }
 
+bool
+machineboot_parse_dtb(const void * dtb, unsigned long len)
+{
+	return fdt_check_full(dtb, len) == 0;
+}
+
 void
-MachineBoot_Entry(unsigned long magic, unsigned long dtb_addr)
+MachineBoot_Entry(unsigned long magic, paddr_t dtb_paddr, unsigned long dtb_len)
 {
 	if (magic != 0x10CA5201) {
 		Halt();
 	}
+	
+	const void * dtb = (const void *)DMPA2VA(dtb_paddr);
+	
+	if (!machineboot_parse_dtb(dtb, dtb_len)){
+		Halt();
+	}
+
 
 	// initialize metal mode
 	mtl_init();