• Eugeniy Paltsev's avatar
    ARC: U-boot: check arguments paranoidly · e7264579
    Eugeniy Paltsev authored
    commit a66f2e57bd566240d8b3884eedf503928fbbe557 upstream.
    
    Handle U-boot arguments paranoidly:
     * don't allow to pass unknown tag.
     * try to use external device tree blob only if corresponding tag
       (TAG_DTB) is set.
     * don't check uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.
    
    NOTE:
    If U-boot args are invalid we skip them and try to use embedded device
    tree blob. We can't panic on invalid U-boot args as we really pass
    invalid args due to bug in U-boot code.
    This happens if we don't provide external DTB to U-boot and
    don't set 'bootargs' U-boot environment variable (which is default
    case at least for HSDK board) In that case we will pass
    {r0 = 1 (bootargs in r2); r1 = 0; r2 = 0;} to linux which is invalid.
    
    While I'm at it refactor U-boot arguments handling code.
    
    Cc: stable@vger.kernel.org
    Tested-by: default avatarCorentin LABBE <clabbe@baylibre.com>
    Signed-off-by: default avatarEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
    Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    e7264579
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