freebsd kernel with SKQ
bc3ad3a179
Runtime services require special execution environment for the call. Besides that, OS must inform firmware about runtime virtual memory map which will be active during the calls, with the SetVirtualAddressMap() runtime call, done while the 1:1 mapping is still used. There are two complication: the SetVirtualAddressMap() effectively must be done from loader, which needs to know kernel address map in advance. More, despite not explicitely mentioned in the specification, both 1:1 and the map passed to SetVirtualAddressMap() must be active during the SetVirtualAddressMap() call. Second, there are buggy BIOSes which require both mappings active during runtime calls as well, most likely because they fail to identify all relocations to perform. On amd64, we can get rid of both problems by providing 1:1 mapping for the duration of runtime calls, by temprorary remapping user addresses. As result, we avoid the need for loader to know about future kernel address map, and avoid bugs in BIOSes. Typically BIOS only maps something in low 4G. If not runtime bugs, we would take advantage of the DMAP, as previous versions of this patch did. Similar but more complicated trick can be used even for i386 and 32bit runtime, if and when the EFI boot on i386 is supported. We would need a trampoline page, since potentially whole 4G of VA would be switched on calls, instead of only userspace portion on amd64. Context switches are disabled for the duration of the call, FPU access is granted, and interrupts are not disabled. The later is possible because kernel is mapped during calls. To test, the sysctl mib debug.efi_time is provided, setting it to 1 makes one call to EFI get_time() runtime service, on success the efitm structure is printed to the control terminal. Load efirt.ko, or add EFIRT option to the kernel config, to enable code. Discussed with: emaste, imp Tested by: emaste (mac, qemu) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7) and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The `buildkernel` and `installkernel` targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process. See build(7), config(8), and http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information. Note: If you want to build and install the kernel with the `buildkernel` and `installkernel` targets, you might need to build world before. More information is available in the handbook. The kernel configuration files reside in the sys/<arch>/conf sub-directory. GENERIC is the default configuration used in release builds. NOTES contains entries and documentation for all possible devices, not just those commonly used. Source Roadmap: --------------- bin System/user commands. cddl Various commands and libraries under the Common Development and Distribution License. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tests Regression tests which can be run by Kyua. See tests/README for additional information. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html