Changeset a4bd537 in mainline for tools/ew.py

Timestamp:

2019-04-06T13:39:58Z (5 years ago)

Author:

Petr Pavlu <setup@…>

Children:

f7842ef

Parents:

0d073b8

git-author:

Petr Pavlu <setup@…> (2019-03-31 14:09:57)

git-committer:

Petr Pavlu <setup@…> (2019-04-06 13:39:58)

Message:

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.

File:

• tools/ew.py (modified) (4 diffs)

tools/ew.py

@@ -94 +94 @@
         elif platform == 'arm32':
                 return 'system-arm', '-M integratorcp'
+        elif platform == 'arm64':
+                # Check that ROM image is present. Provide the user with
+                # appropriate steps to fix this problem.
+                if not os.path.exists('QEMU_EFI_ARM64.fd'):
+                        sys.stderr.write('Could not find ' +
+                            '\'QEMU_EFI_ARM64.fd\' which is expected to ' +
+                            'contain EDK2 firmware image.\n')
+                        sys.stderr.write('Pre-built image can be obtained by ' +
+                            'running the following command:\n')
+                        sys.stderr.write('$ wget http://snapshots.linaro.org/' +
+                            'components/kernel/leg-virt-tianocore-edk2-' +
+                            'upstream/latest/QEMU-AARCH64/RELEASE_GCC49/' +
+                            'QEMU_EFI.fd -O QEMU_EFI_ARM64.fd\n')
+                        raise Exception
+                return 'system-aarch64', \
+                    '-M virt -cpu cortex-a57 -m 1024 -bios QEMU_EFI_ARM64.fd'
         elif platform == 'ia32':
                 return 'system-i386', pc_options(32)
@@ -208 +224 @@
                 cmdline += ' ' + options
 
-        cmdline += qemu_bd_options()
-
+        if (not 'hdd' in cfg.keys() or cfg['hdd']):
+                cmdline += qemu_bd_options()
         if (not 'net' in cfg.keys()) or cfg['net']:
                 cmdline += qemu_net_options()
@@ -234 +250 @@
         if cfg['image'] == 'image.iso':
                 cmdline += ' -boot d -cdrom image.iso'
+        elif cfg['image'] == 'image.iso@arm64':
+                # Define image.iso cdrom backend.
+                cmdline += ' -drive if=none,file=image.iso,id=cdrom,media=cdrom'
+                # Define scsi bus.
+                cmdline += ' -device virtio-scsi-device'
+                # Define cdrom frontend connected to this scsi bus.
+                cmdline += ' -device scsi-cd,drive=cdrom'
         elif cfg['image'] == 'image.boot':
                 cmdline += ' -kernel image.boot'
@@ -276 +299 @@
                         'xhci' : False,
                         'tablet' : False
+                }
+        },
+        'arm64' : {
+                'virt' : {
+                        'run' : qemu_run,
+                        'image' : 'image.iso@arm64',
+                        'audio' : False,
+                        'console' : True,
+                        'hdd' : False,
+                        'net' : False,
+                        'tablet' : False,
+                        'usb' : False,
+                        'xhci' : False
                 }
         },