Changeset 5072

Timestamp:

Jan 31, 2010 10:46:12 PM (3 years ago)

Author:

stepan

Message:

• Improve help texts for option ROM initialization methods
• disallow REAL_MODE method if ARCH_X86 is not set.

Signed-off-by: Stefan Reinauer <stepan@…>
Acked-by: Stefan Reinauer <stepan@…>

File:

• trunk/src/devices/Kconfig (modified) (3 diffs)

trunk/src/devices/Kconfig

@@ -43 +43 @@
           for network cards (NICs).
 
-# TODO: Describe YABEL vs. x86emu differences in more detail.
 choice
         prompt "Option ROM execution type"
-        default PCI_OPTION_ROM_RUN_REALMODE
+        default PCI_OPTION_ROM_RUN_YABEL if !ARCH_X86
+        default PCI_OPTION_ROM_RUN_REALMODE if ARCH_X86
         depends on PCI_ROM_RUN || VGA_ROM_RUN
 
@@ -52 +52 @@
         prompt "Real mode"
         bool
+        depends on ARCH_X86
         help
           If you select this option, PCI option ROMs will be executed
-          natively on the hardware (a 32bit x86 system is required).
+          natively on the CPU in real mode. No CPU emulation is involved,
+          so this is the fastest, but also the least secure option.
+          (only works on x86/x64 systems)
+
+config PCI_OPTION_ROM_RUN_X86EMU
+        prompt "x86emu"
+        bool
+        help
+          If you select this option, the x86emu CPU emulator will be used to
+          execute PCI option ROMs. 
+          When choosing this option, x86emu will pass through all hardware
+          accesses to memory and IO devices to the underlying memory and IO
+          addresses. While this option prevents option ROMs from doing dirty
+          tricks with the CPU (such as installing SMM modules or hypervisors),
+          they can still access all devices in the system.
+          Choosing x86emu, option ROM execution is slower than native execution
+          in real mode, but faster than the full system emulation YABEL
+          This is the default choice for non-x86 systems.
 
 config PCI_OPTION_ROM_RUN_YABEL
@@ -60 +78 @@
         bool
         help
-          If you select this option, the YABEL BIOS emulator will be used to
+          If you select this option, the YABEL system emulator will be used to
           execute PCI option ROMs.
-
-config PCI_OPTION_ROM_RUN_X86EMU
-        prompt "x86emu"
-        bool
-        help
-          If you select this option, the x86emu BIOS emulator will be used to
-          execute PCI option ROMs.
+          YABEL consists of two parts: It uses x86emu for the CPU emulation and
+          additionally provides a PC system emulation that filters bad device and
+          memory access (such as PCI config space access to other devices than the
+          initialized one).
+          This option best prevents option ROMs from doing dirty tricks with the 
+          system (such as installing SMM modules or hypervisors), but it is also
+          significantly slower than the other option ROM initialization methods.
 
 endchoice