From 610ea6c671685a09afff7ba521bdccda21c84c76 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 1 Oct 2009 14:31:22 +0100 Subject: ARM: 5738/1: Correct TCM documentation It turns out that the TCM memory can be remap:ed by the MMU just like any other memory. Signed-off-by: Linus Walleij Signed-off-by: Russell King --- Documentation/arm/tcm.txt | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/arm/tcm.txt b/Documentation/arm/tcm.txt index 074f4be6667f..77fd9376e6d7 100644 --- a/Documentation/arm/tcm.txt +++ b/Documentation/arm/tcm.txt @@ -29,11 +29,13 @@ TCM location and size. Notice that this is not a MMU table: you actually move the physical location of the TCM around. At the place you put it, it will mask any underlying RAM from the CPU so it is usually wise not to overlap any physical RAM with -the TCM. The TCM memory exists totally outside the MMU and will -override any MMU mappings. +the TCM. -Code executing inside the ITCM does not "see" any MMU mappings -and e.g. register accesses must be made to physical addresses. +The TCM memory can then be remapped to another address again using +the MMU, but notice that the TCM if often used in situations where +the MMU is turned off. To avoid confusion the current Linux +implementation will map the TCM 1 to 1 from physical to virtual +memory in the location specified by the machine. TCM is used for a few things: -- cgit v1.2.3-59-g8ed1b