From b31c3a40b461c0d8e650fe997e802747b700564b Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sun, 8 Feb 2026 12:51:55 +0000
Subject: [PATCH] vm: sparse: ensure that vm_pages for the reserved bsp region
 are created

---
 vm/sparse.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/vm/sparse.c b/vm/sparse.c
index aa28f6a..f0663c2 100644
--- a/vm/sparse.c
+++ b/vm/sparse.c
@@ -23,6 +23,7 @@
    overhead, and the flat memory model may be a better choice.
  */
 #include <mango/arg.h>
+#include <mango/bsp.h>
 #include <mango/machine/cpu.h>
 #include <mango/memblock.h>
 #include <mango/panic.h>
@@ -281,6 +282,25 @@ void vm_sparse_init(void)
 		}
 	}
 
+	struct boot_module bsp;
+	bsp_get_location(&bsp);
+	if (bsp.mod_base & VM_PAGE_MASK) {
+		bsp.mod_base &= ~VM_PAGE_MASK;
+	}
+
+	if (bsp.mod_size & VM_PAGE_MASK) {
+		bsp.mod_size &= ~VM_PAGE_MASK;
+		bsp.mod_size += VM_PAGE_SIZE;
+	}
+
+	/* make sure the vm_pages for the bsp image exist, so that they can be
+	 * mapped in later */
+	for (phys_addr_t i = bsp.mod_base; i < bsp.mod_base + bsp.mod_size;
+	     i += VM_PAGE_SIZE) {
+		struct vm_page *pg = get_or_create_page(i);
+		pg->p_flags = VM_PAGE_RESERVED;
+	}
+
 	for_each_reserved_mem_range(&it, 0x0, pmem_end)
 	{
 		if (it.it_base & VM_PAGE_MASK) {