source: mainline/kernel/arch/arm64/src/mm/page.c

Last change on this file was 84176f3, checked in by Jakub Jermář <jakub@…>, 6 years ago

arm64: Add support for the architecture

This changeset adds basic support to run HelenOS on AArch64, targeting
the QEMU virt platform.

Boot:

  • Boot relies on the EDK II firmware, GRUB2 for EFI and the HelenOS bootloader (UEFI application). EDK II loads GRUB2 from a CD, GRUB2 loads the HelenOS bootloader (via UEFI) which loads OS components.
  • UEFI applications use the PE/COFF format and must be relocatable. The first problem is solved by manually having the PE/COFF headers and tables written in assembler. The relocatable requirement is addressed by compiling the code with -fpic and having the bootloader relocate itself at its startup.

Kernel:

  • Kernel code for AArch64 consists mostly of stubbing out various architecture-specific hooks: virtual memory management, interrupt and exception handling, context switching (including FPU lazy switching), support for virtual timer, atomic sequences and barriers, cache and TLB maintenance, thread and process initialization.
  • The patch adds a kernel driver for GICv2 (interrupt controller).
  • The PL011 kernel driver is extended to allow userspace to take ownership of the console.
  • The current code is not able to dynamically obtain information about available devices on the underlying machine. The port instead implements a machine-func interface similar to the one implemented by arm32. It defines a machine for the QEMU AArch64 virt platform. The configuration (device addresses and IRQ numbers) is then baked into the machine definition.

User space:

  • Uspace code for AArch64 similarly mostly implements architecture-specific hooks: context saving/restoring, syscall support, TLS support.

The patchset allows to boot the system but user interaction with the OS
is not yet possible.

  • Property mode set to 100644
File size: 2.2 KB
Line 
1/*
2 * Copyright (c) 2015 Petr Pavlu
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup kernel_arm64_mm
30 * @{
31 */
32/** @file
33 * @brief Paging related functions.
34 */
35
36#include <arch/mm/page.h>
37#include <genarch/mm/page_pt.h>
38#include <mm/as.h>
39#include <mm/page.h>
40
41/** Initializes page tables. */
42void page_arch_init(void)
43{
44 if (config.cpu_active > 1) {
45 as_switch(NULL, AS_KERNEL);
46 return;
47 }
48
49 page_mapping_operations = &pt_mapping_operations;
50
51 page_table_lock(AS_KERNEL, true);
52
53 /* PA2KA(identity) mapping for all low-memory frames. */
54 for (uintptr_t cur = 0; cur < config.identity_size; cur += FRAME_SIZE) {
55 uintptr_t addr = physmem_base + cur;
56 page_mapping_insert(AS_KERNEL, PA2KA(addr), addr,
57 PAGE_GLOBAL | PAGE_CACHEABLE | PAGE_EXEC | PAGE_WRITE |
58 PAGE_READ);
59 }
60
61 page_table_unlock(AS_KERNEL, true);
62
63 as_switch(NULL, AS_KERNEL);
64}
65
66/** @}
67 */
Note: See TracBrowser for help on using the repository browser.