Reading TTBCR in early boot stage might return the value of the previous kernel's configuration, especially in case of kexec. For example, if normal kernel (first kernel) had run on a configuration of PHYS_OFFSET <= PAGE_OFFSET and crash kernel (second kernel) is running on a configuration PHYS_OFFSET > PAGE_OFFSET, which can happen because it depends on the reserved area for crash kernel, reading TTBCR and using the value to OR other bit fields might be risky because it doesn't have a reset value for TTBCR. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Hoeun Ryu <hoeun.ryu@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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