arch/arm/lib/image.c

/*
 * (C) Copyright 2000-2009
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier: GPL-2.0+
 */

#include <common.h>
#include <mapmem.h>
#include <linux/sizes.h>

DECLARE_GLOBAL_DATA_PTR;

#define LINUX_ARM64_IMAGE_MAGIC 0x644d5241

/* See Documentation/arm64/booting.txt in the Linux kernel */
struct Image_header {
    uint32_t    code0;      /* Executable code */
    uint32_t    code1;      /* Executable code */
    uint64_t    text_offset;    /* Image load offset, LE */
    uint64_t    image_size; /* Effective Image size, LE */
    uint64_t    flags;      /* Kernel flags, LE */
    uint64_t    res2;       /* reserved */
    uint64_t    res3;       /* reserved */
    uint64_t    res4;       /* reserved */
    uint32_t    magic;      /* Magic number */
    uint32_t    res5;
};

int booti_setup(ulong image, ulong *relocated_addr, ulong *size)
{
    struct Image_header *ih;
    uint64_t dst;
    uint64_t image_size, text_offset;

    *relocated_addr = image;

    ih = (struct Image_header *)map_sysmem(image, 0);

    if (ih->magic != le32_to_cpu(LINUX_ARM64_IMAGE_MAGIC)) {
        puts("Bad Linux ARM64 Image magic!\n");
        return 1;
    }

    /*
     * Prior to Linux commit a2c1d73b94ed, the text_offset field
     * is of unknown endianness.  In these cases, the image_size
     * field is zero, and we can assume a fixed value of 0x80000.
     */
    if (ih->image_size == 0) {
        puts("Image lacks image_size field, assuming 16MiB\n");
        image_size = 16 << 20;
        text_offset = 0x80000;
    } else {
        image_size = le64_to_cpu(ih->image_size);
        text_offset = le64_to_cpu(ih->text_offset);
    }

    *size = image_size;

    /*
     * If bit 3 of the flags field is set, the 2MB aligned base of the
     * kernel image can be anywhere in physical memory, so respect
     * images->ep.  Otherwise, relocate the image to the base of RAM
     * since memory below it is not accessible via the linear mapping.
     */
    if (le64_to_cpu(ih->flags) & BIT(3))
        dst = image - text_offset;
    else
        dst = gd->bd->bi_dram[0].start;

    *relocated_addr = ALIGN(dst, SZ_2M) + text_offset;

    unmap_sysmem(ih);

    return 0;
}