ARC: [cmdline] uboot cmdline handling rework

* Moved cmdline copy from asm to "C" - allows for more robust checking
  of pointer validity etc.

* Remove the Kconfig option to do so, base it on a runtime value passed
  by u-boot

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 7 insertions, 19 deletions

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 2c878e964a64..991997269d02 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -49,25 +49,13 @@ stext:
         st.ab   0, [r5,4]
         brlt    r5, r6, 1b
 
-#ifdef CONFIG_CMDLINE_UBOOT
-        ; support for bootloader provided cmdline
-        ;    If cmdline passed by u-boot, then
-        ;    r0 = 1  (because ATAGS parsing, now retired, used to use 0)
-        ;    r1 = magic number (board identity)
-        ;    r2 = addr of cmdline string (somewhere in memory/flash)
-
-        brne    r0, 1, .Lother_bootup_chores    ; u-boot didn't pass cmdline
-        breq    r2, 0, .Lother_bootup_chores    ; or cmdline is NULL
-
-        mov     r5, @command_line
-1:
-        ldb.ab  r6, [r2, 1]
-        breq    r6, 0, .Lother_bootup_chores
-        b.d     1b
-        stb.ab  r6, [r5, 1]
-#endif
-
-.Lother_bootup_chores:
+        ; 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
+        ;    r2 = pointer to uboot provided cmdline or external DTB in mem
+        ; These are handled later in setup_arch()
+        st      r0, [@uboot_tag]
+        st      r2, [@uboot_arg]
 
         ; Identify if running on ISS vs Silicon
         ;       IDENTITY Reg [ 3  2  1  0 ]