bbl: copy dtb after the kernel

bbl/bbl.c

@@ -4,10 +4,25 @@
 #include "vm.h"
 #include "bits.h"
 #include "config.h"
+#include "fdt.h"
 #include <string.h>
 
 static const void* entry_point;
 
+static uintptr_t dtb_output()
+{
+  extern char _payload_end;
+  uintptr_t end = (uintptr_t) &_payload_end;
+  return (end + MEGAPAGE_SIZE - 1) / MEGAPAGE_SIZE * MEGAPAGE_SIZE;
+}
+
+static void filter_dtb(uintptr_t source)
+{
+  uintptr_t dest = dtb_output();
+  uint32_t size = fdt_size(source);
+  memcpy((void*)dest, (void*)source, size);
+}
+
 void boot_other_hart(uintptr_t dtb)
 {
   const void* entry;
@@ -15,12 +30,13 @@ void boot_other_hart(uintptr_t dtb)
     entry = entry_point;
     mb();
   } while (!entry);
-  enter_supervisor_mode(entry, read_csr(mhartid), dtb);
+  enter_supervisor_mode(entry, read_csr(mhartid), dtb_output());
 }
 
 void boot_loader(uintptr_t dtb)
 {
   extern char _payload_start;
+  filter_dtb(dtb);
 #ifdef PK_ENABLE_LOGO
   print_logo();
 #endif