/*
 * Copyright (c) 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <image.h>
#include <android_image.h>
#include <malloc.h>
#include <errno.h>
#ifdef CONFIG_ANDROID_AB_BOOT
#include <android_ab_boot.h>
#endif

#define ANDROID_IMAGE_DEFAULT_KERNEL_ADDR	0x10008000

#define KDTB_MAGIC "KDTB"
#define KDTB_MAGIC_SZ (sizeof(KDTB_MAGIC) - 1)

extern bool validate_bootimg_memory(unsigned int start_addr, unsigned int size);

/*************************************************
 * The Kernel is packed along with its dtb file
 * The format is [header][kernel][dtb file]
 * This is the header
 * **********************************************/
typedef struct __attribute__((__packed__)) KDTB_HEADER {
        char magic[KDTB_MAGIC_SZ];
        uint32_t kernel_size;
        uint32_t dtb_size;
} KDTB_HEADER;

typedef struct KDTB_PARSED {
        unsigned char *kernel_addr;
        uint32_t kernel_size;
        unsigned char *dtb_addr;
        uint32_t dtb_size;
} KDTB_PARSED;

static const unsigned char lzop_magic[] = {
        0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
};

static const unsigned char gzip_magic[] = {
        0x1f, 0x8b
};

static char andr_tmp_str[ANDR_BOOT_ARGS_SIZE + 1];

static int parse_kern_dtb(unsigned char *kern_dtb, unsigned kern_dtb_size,
                KDTB_PARSED *parsed) {
        KDTB_HEADER header;
        memcpy(&header, kern_dtb, sizeof(header));
        if (memcmp(KDTB_MAGIC, header.magic, KDTB_MAGIC_SZ) != 0) {
                return ANDR_BOOT_KDTB_NOT_FOUND;
        }

        unsigned expected_kernel_size = le32_to_cpu(header.kernel_size)
                                        + le32_to_cpu(header.dtb_size)
                                        + sizeof(header);
        if (expected_kernel_size != kern_dtb_size) {
                printf("the expected kern-dtb size is: %u\n", expected_kernel_size);
                printf("the actual kern-dtb size is: %u\n", kern_dtb_size);
                // For now, don't error out on this condition. Seems the
                // hdr->kernel_size value is not used in current code, so there is no
                // way to assert this.
        }
        parsed->kernel_addr = kern_dtb + sizeof(header);
        if ((uintptr_t)parsed->kernel_addr & 0x3) {
                printf("Kernel must be 4 byte aligned\n");
                return ANDR_BOOT_KDTB_INVALID;
        }
        parsed->kernel_size = le32_to_cpu(header.kernel_size);
        parsed->dtb_addr = parsed->kernel_addr + parsed->kernel_size;
        parsed->dtb_size = le32_to_cpu(header.dtb_size);

        return 0;
}

static ulong android_image_get_kernel_addr(const struct andr_img_hdr *hdr)
{
	/*
	 * All the Android tools that generate a boot.img use this
	 * address as the default.
	 *
	 * Even though it doesn't really make a lot of sense, and it
	 * might be valid on some platforms, we treat that adress as
	 * the default value for this field, and try to execute the
	 * kernel in place in such a case.
	 *
	 * Otherwise, we will return the actual value set by the user.
	 */
	if (hdr->kernel_addr == ANDROID_IMAGE_DEFAULT_KERNEL_ADDR)
		return (ulong)hdr + hdr->page_size;

	return hdr->kernel_addr;
}

/**
 * android_image_get_kernel() - processes kernel part of Android boot images
 * @hdr:	Pointer to image header, which is at the start
 *			of the image.
 * @verify:	Checksum verification flag. Currently unimplemented.
 * @os_data:	Pointer to a ulong variable, will hold os data start
 *			address.
 * @os_len:	Pointer to a ulong variable, will hold os data length.
 *
 * This function returns the os image's start address and length. Also,
 * it appends the kernel command line to the bootargs env variable.
 *
 * Return: Zero, os start address and length on success,
 *		otherwise on failure.
 */
int android_image_get_kernel(const struct andr_img_hdr *hdr, int verify,
			     ulong *os_data, ulong *os_len)
{
        ulong end;
	u32 kernel_addr = android_image_get_kernel_addr(hdr);

	/*
	 * Not all Android tools use the id field for signing the image with
	 * sha1 (or anything) so we don't check it. It is not obvious that the
	 * string is null terminated so we take care of this.
	 */
	strncpy(andr_tmp_str, hdr->name, ANDR_BOOT_NAME_SIZE);
	andr_tmp_str[ANDR_BOOT_NAME_SIZE] = '\0';
	if (strlen(andr_tmp_str))
		printf("Android's image name: %s\n", andr_tmp_str);

	printf("Kernel load addr 0x%08x size %u KiB\n",
	       kernel_addr, DIV_ROUND_UP(hdr->kernel_size, 1024));

        if (!validate_bootimg_memory(kernel_addr, DIV_ROUND_UP(hdr->kernel_size, 1024))) {
                printf("Kernel image overlaps with reserved memory areas\n");
                return -ENOMEM;
        }

	int len = 0;
	if (*hdr->cmdline) {
		printf("Kernel command line: %s\n", hdr->cmdline);
		len += strlen(hdr->cmdline);
	}

	char *bootargs = getenv("bootargs");
	if (bootargs)
		len += strlen(bootargs);

	char *newbootargs = malloc(len + 2);
	if (!newbootargs) {
		puts("Error: malloc in android_image_get_kernel failed!\n");
		return -ENOMEM;
	}
	*newbootargs = '\0';

	if (bootargs) {
		strcpy(newbootargs, bootargs);
		strcat(newbootargs, " ");
	}
	if (*hdr->cmdline)
		strcat(newbootargs, hdr->cmdline);

	setenv("bootargs", newbootargs);

#ifdef CONFIG_ANDROID_AB_BOOT
        android_set_active_slot_bootargs();
#endif // CONFIG_ANDROID_AB_BOOT

        /* Kernel or kernel-dtb file exists at this location. */
        void *kernel = (unsigned char *)hdr + hdr->page_size;

        KDTB_PARSED parsed = {0};
        int ret = parse_kern_dtb(kernel, hdr->kernel_size, &parsed);

        if (ret == ANDR_BOOT_KDTB_INVALID)
                return ret;

        if (ret == 0) {
                /* kernel-dtb file found. */
                printf("found kdtb.\n");
                if (os_data) {
                        *os_data = (ulong)parsed.kernel_addr;
                }
                if (os_len)
                        *os_len = parsed.kernel_size;
                images.ft_len = parsed.dtb_size;
                images.ft_addr = (char *)parsed.dtb_addr;

                end = (ulong)hdr;
                end += hdr->page_size;
                end += ALIGN(hdr->kernel_size, hdr->page_size);
                images.rd_start = end;
                return 0;
        }
	if (os_data) {
		*os_data = (ulong)kernel;
	}
	if (os_len)
		*os_len = hdr->kernel_size;

	return 0;
}

int android_image_check_header(const struct andr_img_hdr *hdr)
{
	return memcmp(ANDR_BOOT_MAGIC, hdr->magic, ANDR_BOOT_MAGIC_SIZE);
}

ulong android_image_get_end(const struct andr_img_hdr *hdr)
{
	ulong end;
	/*
	 * The header takes a full page, the remaining components are aligned
	 * on page boundary
	 */
	end = (ulong)hdr;
	end += hdr->page_size;
	end += ALIGN(hdr->kernel_size, hdr->page_size);
	end += ALIGN(hdr->ramdisk_size, hdr->page_size);
	end += ALIGN(hdr->second_size, hdr->page_size);

	return end;
}

ulong android_image_get_kload(const struct andr_img_hdr *hdr)
{
	return android_image_get_kernel_addr(hdr);
}

int android_image_get_ramdisk(const struct andr_img_hdr *hdr,
			      ulong *rd_data, ulong *rd_len)
{
	if (!hdr->ramdisk_size) {
		*rd_data = *rd_len = 0;
		return -1;
	}

	printf("RAM disk load addr 0x%08x size %u KiB\n",
	       hdr->ramdisk_addr, DIV_ROUND_UP(hdr->ramdisk_size, 1024));

	*rd_data = (unsigned long)hdr;
	*rd_data += hdr->page_size;
	*rd_data += ALIGN(hdr->kernel_size, hdr->page_size);

	*rd_len = hdr->ramdisk_size;
	return 0;
}

ulong android_image_get_comp(const struct andr_img_hdr *os_hdr)
{
        int i;
        unsigned char *src = (unsigned char *)os_hdr + os_hdr->page_size;

        KDTB_PARSED parsed = {0};
        if (parse_kern_dtb(src, os_hdr->kernel_size, &parsed) == 0) {
                src = parsed.kernel_addr;
        }
        unsigned char *begin = src;

        /* read magic: 9 first bytes */
        for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
                if (*src++ != lzop_magic[i])
                        break;
        }
        if (i == ARRAY_SIZE(lzop_magic))
                return IH_COMP_LZO;

        src = begin;
        for (i = 0; i < ARRAY_SIZE(gzip_magic); i++) {
                if (*src++ != gzip_magic[i])
                        break;
        }
        if (i == ARRAY_SIZE(gzip_magic))
                return IH_COMP_GZIP;

        return IH_COMP_NONE;
}