diff options
| author | Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> | 2019-02-14 18:07:44 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2019-02-21 11:03:18 -0800 |
| commit | a66f2e57bd566240d8b3884eedf503928fbbe557 (patch) | |
| tree | 22baea1fbe72569f51bfb9df7cf4f2e96dece0bb /arch/arc/kernel/head.S | |
| parent | e494239a007e601448110ac304fe055951f9de3b (diff) | |
| download | linux-a66f2e57bd566240d8b3884eedf503928fbbe557.tar.gz | |
ARC: U-boot: check arguments paranoidly
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: Corentin LABBE <clabbe@baylibre.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/head.S')
| -rw-r--r-- | arch/arc/kernel/head.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S index 26e33a8b2d18..1f945d0f40da 100644 --- a/arch/arc/kernel/head.S +++ b/arch/arc/kernel/head.S @@ -103,9 +103,9 @@ ENTRY(stext) #ifdef CONFIG_ARC_UBOOT_SUPPORT ; Uboot - kernel ABI ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2 - ; r1 = magic number (board identity, unused as of now + ; r1 = magic number (always zero as of now) ; r2 = pointer to uboot provided cmdline or external DTB in mem - ; These are handled later in setup_arch() + ; These are handled later in handle_uboot_args() st r0, [@uboot_tag] st r2, [@uboot_arg] #endif |