Changeset a4bd537 in mainline for boot/genarch/src/efi.c

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:

• boot/genarch/src/efi.c (modified) (1 diff)

boot/genarch/src/efi.c

@@ -42 +42 @@
         return NULL;
 }
+
+efi_status_t efi_get_memory_map(efi_system_table_t *st,
+    sysarg_t *memory_map_size, efi_v1_memdesc_t **memory_map, sysarg_t *map_key,
+    sysarg_t *descriptor_size, uint32_t *descriptor_version)
+{
+        efi_status_t status;
+
+        *memory_map_size = 8 * sizeof(**memory_map);
+
+        do {
+                /* Allocate space for the memory map. */
+                status = st->boot_services->allocate_pool(EFI_LOADER_DATA,
+                    *memory_map_size, (void **) memory_map);
+                if (status != EFI_SUCCESS)
+                        return status;
+
+                /* Try to obtain the map. */
+                status = st->boot_services->get_memory_map(memory_map_size,
+                    *memory_map, map_key, descriptor_size, descriptor_version);
+                if (status == EFI_SUCCESS)
+                        return status;
+
+                /* An error occurred, release the allocated memory. */
+                st->boot_services->free_pool(*memory_map);
+        } while (status == EFI_BUFFER_TOO_SMALL);
+
+        return status;
+}