sim: Add a copied symbol table for the kernel on physical address

In fs simulation, the kernel is loaded to physical address first and
then it would relocate itself to virtual address. The address which
using by kernel symbol table is virtual address. To debug the process
before kernel relocated to virutal memory, we need another copy of
symbol table for physical address.

Change-Id: I38107ff94b301df1a5170dd98774df88cfb02298
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43104
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/sim/kernel_workload.cc

@@ -61,6 +61,13 @@ KernelWorkload::KernelWorkload(const Params &p) : Workload(p),
         });
 
         kernelSymtab = kernelObj->symtab();
+        auto initKernelSymtab = kernelSymtab.mask(_loadAddrMask)
+            ->offset(_loadAddrOffset)
+            ->rename([](std::string &name) {
+                name = "kernel_init." + name;
+            });
+
+        Loader::debugSymbolTable.insert(*initKernelSymtab);
         Loader::debugSymbolTable.insert(kernelSymtab);
     }