proxyutils: workaround for mem_size_actual == 0

AsahiLinux#363 (comment)

proxyclient/m1n1/proxyutils.py

@@ -6,7 +6,7 @@
 
 from .asm import ARMAsm
 from .proxy import *
-from .utils import Reloadable, chexdiff32
+from .utils import Reloadable, chexdiff32, align_up
 from .tgtypes import *
 from .sysreg import *
 from .malloc import Heap
@@ -54,6 +54,10 @@ def __init__(self, p: M1N1Proxy, heap_size=1024 * 1024 * 1024):
 
         self.ba = self.iface.readstruct(self.ba_addr, BootArgs)
 
+        # generate a usable value for mem_size_actual if missing, in the same way as startup.c
+        if self.ba.mem_size_actual == 0:
+            self.ba.mem_size_actual = align_up(self.ba.phys_base + self.ba.mem_size - 0x800000000, 1 << 30)
+
         # We allocate a 128MB heap, 128MB after the m1n1 heap, without telling it about it.
         # This frees up from having to coordinate memory management or free stuff after a Python
         # script runs, at the expense that if m1n1 ever uses more than 128MB of heap it will