source: mainline/kernel/arch/arm64/src/mm/as.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: 2.4 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 Address space functions.
34 */
35
36#include <arch/mm/as.h>
37#include <arch/regutils.h>
38#include <genarch/mm/asid_fifo.h>
39#include <genarch/mm/page_pt.h>
40#include <mm/as.h>
41#include <mm/asid.h>
42
43/** Architecture dependent address space init.
44 *
45 * Since ARM64 supports page tables, #as_pt_operations are used.
46 */
47void as_arch_init(void)
48{
49 as_operations = &as_pt_operations;
50 asid_fifo_init();
51}
52
53/** Perform ARM64-specific tasks when an address space becomes active on the
54 * processor.
55 *
56 * Change the level 0 page table (this is normally done by
57 * SET_PTL0_ADDRESS_ARCH() on other architectures) and install ASID.
58 *
59 * @param as Address space.
60 */
61void as_install_arch(as_t *as)
62{
63 uint64_t val;
64
65 val = (uint64_t) as->genarch.page_table;
66 if (as->asid != ASID_KERNEL) {
67 val |= (uint64_t) as->asid << TTBR0_ASID_SHIFT;
68 TTBR0_EL1_write(val);
69 } else
70 TTBR1_EL1_write(val);
71}
72
73/** @}
74 */
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