configs: Remove default kernel value from system creation

Kernel was being set using a placeholder and then assigned the
correct value. This would generate the following error if the
placeholder file did not exist:
'IOError: Can't find file <placeholder> on path'

This patch follows the same directions of commit
12eca7ac04 and removes the default
values, forcing the user to properly configure the kernel.

Change-Id: I0eb45d12eda6b6efe9a3fe118996b640844a7b34
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/11850
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

configs/common/FSConfig.py

@@ -131,7 +131,6 @@ def makeLinuxAlphaSystem(mem_mode, mdesc=None, ruby=False, cmdline=None):
     self.intrctrl = IntrControl()
     self.mem_mode = mem_mode
     self.terminal = Terminal()
-    self.kernel = binary('vmlinux')
     self.pal = binary('ts_osfpal')
     self.console = binary('console')
     if not cmdline:
@@ -429,7 +428,6 @@ def makeLinuxMipsSystem(mem_mode, mdesc=None, cmdline=None):
     self.intrctrl = IntrControl()
     self.mem_mode = mem_mode
     self.terminal = Terminal()
-    self.kernel = binary('mips/vmlinux')
     self.console = binary('mips/console')
     if not cmdline:
         cmdline = 'root=/dev/hda1 console=ttyS0'
@@ -657,7 +655,6 @@ def makeLinuxX86System(mem_mode, numCPUs=1, mdesc=None, Ruby=False,
     if not cmdline:
         cmdline = 'earlyprintk=ttyS0 console=ttyS0 lpj=7999923 root=/dev/hda1'
     self.boot_osflags = fillInCmdline(mdesc, cmdline)
-    self.kernel = binary('x86_64-vmlinux-2.6.22.9')
     return self
 
 

configs/example/fs.py

@@ -125,6 +125,9 @@ def build_test_system(np):
 
     if options.kernel is not None:
         test_sys.kernel = binary(options.kernel)
+    else:
+        print("Error: a kernel must be provided to run in full system mode")
+        sys.exit(1)
 
     if options.script is not None:
         test_sys.readfile = options.script
@@ -231,7 +234,8 @@ def build_drive_system(np):
 
     cmdline = cmd_line_template()
     if buildEnv['TARGET_ISA'] == 'alpha':
-        drive_sys = makeLinuxAlphaSystem(drive_mem_mode, bm[1], cmdline=cmdline)
+        drive_sys = makeLinuxAlphaSystem(drive_mem_mode, bm[1],
+                                         cmdline=cmdline)
     elif buildEnv['TARGET_ISA'] == 'mips':
         drive_sys = makeLinuxMipsSystem(drive_mem_mode, bm[1], cmdline=cmdline)
     elif buildEnv['TARGET_ISA'] == 'sparc':
@@ -265,6 +269,9 @@ def build_drive_system(np):
     drive_sys.cpu.connectAllPorts(drive_sys.membus)
     if options.kernel is not None:
         drive_sys.kernel = binary(options.kernel)
+    else:
+        print("Error: a kernel must be provided to run in full system mode")
+        sys.exit(1)
 
     if CpuConfig.is_kvm_cpu(DriveCPUClass):
         drive_sys.kvm_vm = KvmVM()