Handle case of no mem_size_actual

Newer machines do not always have mem_size_actual filled in in the boot args. When that happens, use mem_size and mask it to a page boundary. Signed-off-by: Daniel Berlin <[email protected]>
AsahiLinux · Dec 1, 2023 · 897ccc3 · 897ccc3
1 parent 736acde
commit 897ccc3
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/src/memory.c b/src/memory.c
@@ -13,7 +13,8 @@
 #include "utils.h"
 #include "xnuboot.h"
 
-#define PAGE_SIZE       0x4000
+#define PAGE_SIZE 0x4000
+/* Cache line size on M3+ is 128 bytes, so we will just invalidate unnecessarily here */
 #define CACHE_LINE_SIZE 64
 
 #define CACHE_RANGE_OP(func, op)                                                                   \
@@ -411,7 +412,14 @@ static void mmu_add_default_mappings(void)
      * With SPRR enabled, this becomes RW.
      * This range includes all real RAM, including carveouts
      */
-    mmu_add_mapping(ram_base, ram_base, cur_boot_args.mem_size_actual, MAIR_IDX_NORMAL, PERM_RWX);
+
+    /*
+     * Newer machines (m3+) do not always have mem_size_actual filled in.  In this case,
+     * use mem size.  Either way, mask it to a page boundary.
+     */
+    u64 mem_size =
+        cur_boot_args.mem_size_actual ? cur_boot_args.mem_size_actual : cur_boot_args.mem_size;
+    mmu_add_mapping(ram_base, ram_base, mem_size & ~(PAGE_SIZE), MAIR_IDX_NORMAL, PERM_RWX);
 
     /* Unmap carveout regions */
     mcc_unmap_carveouts();