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author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-04-14 20:51:10 +0200 |
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committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-15 14:20:24 +0200 |
commit | dc7a12bdfccd94c31f79e294f16f7549bd411b49 (patch) | |
tree | 81da5ca148347b94c4539234f50d4bca6465e2f8 /Documentation/arm/memory.txt | |
parent | docs: early-userspace: convert docs to ReST and rename to *.rst (diff) | |
download | linux-dc7a12bdfccd94c31f79e294f16f7549bd411b49.tar.xz linux-dc7a12bdfccd94c31f79e294f16f7549bd411b49.zip |
docs: arm: convert docs to ReST and rename to *.rst
Converts ARM the text files to ReST, preparing them to be an
architecture book.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
Diffstat (limited to 'Documentation/arm/memory.txt')
-rw-r--r-- | Documentation/arm/memory.txt | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt deleted file mode 100644 index 546a39048eb0..000000000000 --- a/Documentation/arm/memory.txt +++ /dev/null @@ -1,88 +0,0 @@ - Kernel Memory Layout on ARM Linux - - Russell King <rmk@arm.linux.org.uk> - November 17, 2005 (2.6.15) - -This document describes the virtual memory layout which the Linux -kernel uses for ARM processors. It indicates which regions are -free for platforms to use, and which are used by generic code. - -The ARM CPU is capable of addressing a maximum of 4GB virtual memory -space, and this must be shared between user space processes, the -kernel, and hardware devices. - -As the ARM architecture matures, it becomes necessary to reserve -certain regions of VM space for use for new facilities; therefore -this document may reserve more VM space over time. - -Start End Use --------------------------------------------------------------------------- -ffff8000 ffffffff copy_user_page / clear_user_page use. - For SA11xx and Xscale, this is used to - setup a minicache mapping. - -ffff4000 ffffffff cache aliasing on ARMv6 and later CPUs. - -ffff1000 ffff7fff Reserved. - Platforms must not use this address range. - -ffff0000 ffff0fff CPU vector page. - The CPU vectors are mapped here if the - CPU supports vector relocation (control - register V bit.) - -fffe0000 fffeffff XScale cache flush area. This is used - in proc-xscale.S to flush the whole data - cache. (XScale does not have TCM.) - -fffe8000 fffeffff DTCM mapping area for platforms with - DTCM mounted inside the CPU. - -fffe0000 fffe7fff ITCM mapping area for platforms with - ITCM mounted inside the CPU. - -ffc00000 ffefffff Fixmap mapping region. Addresses provided - by fix_to_virt() will be located here. - -fee00000 feffffff Mapping of PCI I/O space. This is a static - mapping within the vmalloc space. - -VMALLOC_START VMALLOC_END-1 vmalloc() / ioremap() space. - Memory returned by vmalloc/ioremap will - be dynamically placed in this region. - Machine specific static mappings are also - located here through iotable_init(). - VMALLOC_START is based upon the value - of the high_memory variable, and VMALLOC_END - is equal to 0xff800000. - -PAGE_OFFSET high_memory-1 Kernel direct-mapped RAM region. - This maps the platforms RAM, and typically - maps all platform RAM in a 1:1 relationship. - -PKMAP_BASE PAGE_OFFSET-1 Permanent kernel mappings - One way of mapping HIGHMEM pages into kernel - space. - -MODULES_VADDR MODULES_END-1 Kernel module space - Kernel modules inserted via insmod are - placed here using dynamic mappings. - -00001000 TASK_SIZE-1 User space mappings - Per-thread mappings are placed here via - the mmap() system call. - -00000000 00000fff CPU vector page / null pointer trap - CPUs which do not support vector remapping - place their vector page here. NULL pointer - dereferences by both the kernel and user - space are also caught via this mapping. - -Please note that mappings which collide with the above areas may result -in a non-bootable kernel, or may cause the kernel to (eventually) panic -at run time. - -Since future CPUs may impact the kernel mapping layout, user programs -must not access any memory which is not mapped inside their 0x0001000 -to TASK_SIZE address range. If they wish to access these areas, they -must set up their own mappings using open() and mmap(). |