Android recovery 和reboot(2)

第二种会去读smem
unsigned check_reboot_mode(void)
{
    unsigned mode[2] = {0, 0};
    unsigned int mode_len = sizeof(mode);
    unsigned smem_status;

    smem_status = smem_read_alloc_entry(SMEM_APPS_BOOT_MODE,
                    &mode, mode_len );
    if(smem_status)
    {
      dprintf(CRITICAL, "ERROR: unable to read shared memory for reboot mode/n");
      return 0;
    }
    return mode[0];
}


unsigned smem_read_alloc_entry(smem_mem_type_t type, void *buf, int len)
{
    struct smem_alloc_info *ainfo;
    unsigned *dest = buf;
    unsigned src;
    unsigned size;

    if (((len & 0x3) != 0) || (((unsigned)buf & 0x3) != 0))
        return 1;

    if (type < SMEM_FIRST_VALID_TYPE || type > SMEM_LAST_VALID_TYPE)
        return 1;

    /* TODO: Use smem spinlocks */
    ainfo = &smem->alloc_info[type];
    if (readl(&ainfo->allocated) == 0)
        return 1;

    if ((size = readl(&ainfo->size)) != (unsigned)len)
        return 1;

    src = MSM_SHARED_BASE + readl(&ainfo->offset);
    for (; size > 0; src += 4, size -= 4)
        *(dest++) = readl(src);

    return 0;
}


这个文章只解释如何进入recovery。