Diffstat (limited to 'arch/m68knommu')
1 files changed, 44 insertions, 34 deletions
diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig
index 6c6980b9b6d..8b6e723eb82 100644
@@ -472,38 +472,46 @@ config 4KSTACKS
running more threads on a system and also reduces the pressure
on the VM subsystem for higher order allocations.
- prompt "RAM size"
- default AUTO
- bool "AUTO"
- Configure the RAM size on your platform. Many platforms can auto
- detect this, on those choose the AUTO option. Otherwise set the
- RAM size you intend using.
- bool "4MiB"
- Set RAM size to be 4MiB.
- bool "8MiB"
- Set RAM size to be 8MiB.
- bool "16MiB"
- Set RAM size to be 16MiB.
- bool "32MiB"
- Set RAM size to be 32MiB.
+comment "RAM configuration"
+ hex "Address of the base of RAM"
+ default "0"
+ Define the address that RAM starts at. On many platforms this is
+ 0, the base of the address space. And this is the default. Some
+ platforms choose to setup their RAM at other addresses within the
+ processor address space.
+ hex "Size of RAM (in bytes)"
+ default "0x400000"
+ Define the size of the system RAM. If you select 0 then the
+ kernel will try to probe the RAM size at runtime. This is not
+ supported on all CPU types.
+ hex "Address of the base of system vectors"
+ default "0"
+ Define the address of the the system vectors. Commonly this is
+ put at the start of RAM, but it doesn't have to be. On ColdFire
+ platforms this address is programmed into the VBR register, thus
+ actually setting the address to use.
+ hex "Address of the base of kernel code"
+ default "0x400"
+ Typically on m68k systems the kernel will not start at the base
+ of RAM, but usually some small offset from it. Define the start
+ address of the kernel here. The most common setup will have the
+ processor vectors at the base of RAM and then the start of the
+ kernel. On some platforms some RAM is reserved for boot loaders
+ and the kernel starts after that. The 0x400 default was based on
+ a system with the RAM based at address 0, and leaving enough room
+ for the theoretical maximum number of 256 vectors.
prompt "RAM bus width"
@@ -511,7 +519,7 @@ choice
Select the physical RAM data bus size. Not needed on most platforms,
so you can generally choose AUTO.
@@ -545,7 +553,9 @@ config RAMKERNEL
- The kernel will be resident in FLASH/ROM when running.
+ The kernel will be resident in FLASH/ROM when running. This is
+ often referred to as Execute-in-Place (XIP), since the kernel
+ code executes from the position it is stored in the FLASH/ROM.