source: mainline/boot/arch/arm64/src/main.c@ f8fb03b

/*
 * Copyright (c) 2015 Petr Pavlu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup boot_arm64
 * @{
 */
/** @file
 * @brief Bootstrap.
 */

#include <stddef.h>
#include <align.h>
#include <arch/arch.h>
#include <arch/asm.h>
#include <arch/barrier.h>
#include <arch/main.h>
#include <arch/regutils.h>
#include <arch/types.h>
#include <errno.h>
#include <inflate.h>
#include <kernel.h>
#include <macros.h>
#include <memstr.h>
#include <payload.h>
#include <printf.h>
#include <putchar.h>
#include <str.h>
#include <version.h>

static efi_system_table_t *efi_system_table;

/** Translate given UEFI memory type to the bootinfo memory type.
 *
 * @param type UEFI memory type.
 */
static memtype_t get_memtype(uint32_t type)
{
        switch (type) {
        case EFI_RESERVED:
        case EFI_RUNTIME_SERVICES_CODE:
        case EFI_RUNTIME_SERVICES_DATA:
        case EFI_UNUSABLE_MEMORY:
        case EFI_ACPI_MEMORY_NVS:
        case EFI_MEMORY_MAPPED_IO:
        case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
        case EFI_PAL_CODE:
                return MEMTYPE_UNUSABLE;
        case EFI_LOADER_CODE:
        case EFI_LOADER_DATA:
        case EFI_BOOT_SERVICES_CODE:
        case EFI_BOOT_SERVICES_DATA:
        case EFI_CONVENTIONAL_MEMORY:
        case EFI_PERSISTENT_MEMORY:
                return MEMTYPE_AVAILABLE;
        case EFI_ACPI_RECLAIM_MEMORY:
                return MEMTYPE_ACPI_RECLAIM;
        }

        return MEMTYPE_UNUSABLE;
}

/** Send a byte to the UEFI console output.
 *
 * @param byte Byte to send.
 */
static void scons_sendb(uint8_t byte)
{
        int16_t out[2] = { byte, '\0' };
        efi_system_table->cons_out->output_string(efi_system_table->cons_out,
            out);
}

/** Display a character.
 *
 * @param ch Character to display.
 */
void putwchar(wchar_t ch)
{
        if (ch == '\n')
                scons_sendb('\r');

        if (ascii_check(ch))
                scons_sendb((uint8_t) ch);
        else
                scons_sendb('?');
}

efi_status_t bootstrap(void *efi_handle_in,
    efi_system_table_t *efi_system_table_in, void *load_address)
{
        efi_status_t status;
        uint64_t current_el;
        uint64_t memmap = 0;
        sysarg_t memmap_size;
        sysarg_t memmap_key;
        sysarg_t memmap_descriptor_size;
        uint32_t memmap_descriptor_version;
        uint64_t alloc_addr = 0;
        sysarg_t alloc_pages = 0;

        /*
         * Bootinfo structure is dynamically allocated in the ARM64 port. It is
         * placed directly after the inflated components. This assures that if
         * the kernel identity maps the first gigabyte of the main memory in the
         * kernel/upper address space then it can access the bootinfo because
         * the inflated components and bootinfo can always fit in this area.
         */
        bootinfo_t *bootinfo;

        efi_system_table = efi_system_table_in;

        version_print();

        printf("Boot loader: %p -> %p\n", loader_start, loader_end);
        printf("\nMemory statistics\n");
        printf(" %p|%p: loader\n", load_address, load_address);
        printf(" %p|%p: UEFI system table\n", efi_system_table_in,
            efi_system_table_in);

        /* Validate the exception level. */
        current_el = CurrentEL_read();
        if (current_el != CURRENT_EL_EL1) {
                printf("Error: Unexpected CurrentEL value %0#18" PRIx64 ".\n",
                    current_el);
                status = EFI_UNSUPPORTED;
                goto fail;
        }

        /* Obtain memory map. */
        status = efi_get_memory_map(efi_system_table, &memmap_size,
            (efi_v1_memdesc_t **) &memmap, &memmap_key, &memmap_descriptor_size,
            &memmap_descriptor_version);
        if (status != EFI_SUCCESS) {
                printf("Error: Unable to obtain initial memory map, status "
                    "code: %" PRIx64 ".\n", status);
                goto fail;
        }

        /* Find start of usable RAM. */
        uint64_t memory_base = (uint64_t) -1;
        for (sysarg_t i = 0; i < memmap_size / memmap_descriptor_size; i++) {
                efi_v1_memdesc_t *desc = (void *) memmap +
                    (i * memmap_descriptor_size);
                if (get_memtype(desc->type) != MEMTYPE_AVAILABLE ||
                    !(desc->attribute & EFI_MEMORY_WB))
                        continue;

                if (desc->phys_start < memory_base)
                        memory_base = desc->phys_start;
        }

        /* Deallocate memory holding the map. */
        efi_system_table->boot_services->free_pool((void *) memmap);
        memmap = 0;

        if (memory_base == (uint64_t) -1) {
                printf("Error: Memory map does not contain any usable RAM.\n");
                status = EFI_UNSUPPORTED;
                goto fail;
        }

        /*
         * Check that everything is aligned on a 4kB boundary and the kernel can
         * be placed by the decompression code at a correct address.
         */

        /* Statically check PAGE_SIZE and BOOT_OFFSET. */
        _Static_assert(PAGE_SIZE == 4096, "PAGE_SIZE must be equal to 4096");
        _Static_assert(IS_ALIGNED(BOOT_OFFSET, PAGE_SIZE),
            "BOOT_OFFSET must be a multiple of PAGE_SIZE");

        /*
         * Dynamically check the memory base. The condition should be always
         * true because UEFI guarantees each physical/virtual address in the
         * memory map is aligned on a 4kB boundary.
         */
        if (!IS_ALIGNED(memory_base, PAGE_SIZE)) {
                printf("Error: Start of usable RAM (%p) is not aligned on a "
                    "4kB boundary.\n", (void *) memory_base);
                status = EFI_UNSUPPORTED;
                goto fail;
        }

        /*
         * Calculate where the components (including the kernel) will get
         * placed.
         */
        uint64_t decompress_base = memory_base + BOOT_OFFSET;
        printf(" %p|%p: kernel entry point\n", (void *) decompress_base,
            (void *) decompress_base);

        /*
         * Allocate memory for the decompressed components and for the bootinfo.
         */
        uint64_t component_pages =
            ALIGN_UP(payload_unpacked_size(), EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
        uint64_t bootinfo_pages = ALIGN_UP(sizeof(*bootinfo), EFI_PAGE_SIZE) /
            EFI_PAGE_SIZE;
        alloc_pages = component_pages + bootinfo_pages;
        alloc_addr = decompress_base;
        status = efi_system_table->boot_services->allocate_pages(
            EFI_ALLOCATE_ADDRESS, EFI_LOADER_CODE, alloc_pages, &alloc_addr);
        if (status != EFI_SUCCESS) {
                printf("Error: Unable to allocate memory for inflated "
                    "components and bootinfo, status code: %" PRIx64 ".\n",
                    status);
                goto fail;
        }

        bootinfo = (void *) alloc_addr + component_pages * EFI_PAGE_SIZE;
        printf(" %p|%p: boot info structure\n", bootinfo, bootinfo);
        memset(bootinfo, 0, sizeof(*bootinfo));

        /* Decompress the components. */
        uint8_t *kernel_dest = (uint8_t *) alloc_addr;
        uint8_t *ram_end = kernel_dest + component_pages * EFI_PAGE_SIZE;

        extract_payload(&bootinfo->taskmap, kernel_dest, ram_end,
            (uintptr_t) kernel_dest, ensure_visibility);

        /* Get final memory map. */
        status = efi_get_memory_map(efi_system_table, &memmap_size,
            (efi_v1_memdesc_t **) &memmap, &memmap_key, &memmap_descriptor_size,
            &memmap_descriptor_version);
        if (status != EFI_SUCCESS) {
                printf("Error: Unable to obtain final memory map, status code: "
                    "%" PRIx64 ".\n", status);
                goto fail;
        }

        /* Convert the UEFI memory map to the bootinfo representation. */
        size_t cnt = 0;
        memtype_t current_type = MEMTYPE_UNUSABLE;
        void *current_start = 0;
        size_t current_size = 0;
        sysarg_t memmap_items_count = memmap_size / memmap_descriptor_size;
        for (sysarg_t i = 0; i < memmap_items_count; i++) {
                efi_v1_memdesc_t *desc = (void *) memmap +
                    (i * memmap_descriptor_size);

                /* Get type of the new area. */
                memtype_t type;
                if (!(desc->attribute & EFI_MEMORY_WB))
                        type = MEMTYPE_UNUSABLE;
                else
                        type = get_memtype(desc->type);

                /* Try to merge the new area with the previous one. */
                if (type == current_type &&
                    (uint64_t)current_start + current_size == desc->phys_start) {
                        current_size += desc->pages * EFI_PAGE_SIZE;
                        if (i != memmap_items_count - 1)
                                continue;
                }

                /* Record the previous area. */
                if (current_type != MEMTYPE_UNUSABLE) {
                        if (cnt >= MEMMAP_MAX_RECORDS) {
                                printf("Error: Too many usable memory "
                                    "areas.\n");
                                status = EFI_UNSUPPORTED;
                                goto fail;
                        }
                        bootinfo->memmap.zones[cnt].type = current_type;
                        bootinfo->memmap.zones[cnt].start = current_start;
                        bootinfo->memmap.zones[cnt].size = current_size;
                        cnt++;
                }

                /* Remember the new area. */
                current_type = type;
                current_start = (void *) desc->phys_start;
                current_size = desc->pages * EFI_PAGE_SIZE;
        }
        bootinfo->memmap.cnt = cnt;

        uintptr_t entry = check_kernel_translated((void *) decompress_base,
            BOOT_OFFSET);

        printf("Booting the kernel...\n");

        /* Exit boot services. This is a point of no return. */
        efi_system_table->boot_services->exit_boot_services(efi_handle_in,
            memmap_key);

        entry = memory_base + KA2PA(entry);
        jump_to_kernel((void *) entry, bootinfo);

fail:
        if (memmap != 0)
                efi_system_table->boot_services->free_pool((void *) memmap);

        if (alloc_addr != 0)
                efi_system_table->boot_services->free_pages(alloc_addr,
                    alloc_pages);

        return status;
}

/** @}
 */