Re: how to debug mips AdEL error？ Cause register's ExcCode field equal to '4' (AdEL)

[Bob Zhang <2004.zhang@gmail.com>]

through the kernel panic info:
CPU Regs : ===========================================================
$0 : 00000000 80290000 00000100 fffdffff 00000007 00000006 8023427c 820e83d4
$8 : 00000000 00000000 00000000 820e83dc 820e83f4 820e8000 80278010 00000000
$16: 8028f7b8 0000d32b 0000132b 802a53a0 0000d34d 7fff7d48 00000004 00000014
$24: 8200000c 2abe4090                   820e8000 820e9e70 00000000 0000000a

we can know , the ra register is 0x0000000a
after sub-function executed completely , it will return $ra.

through code trace , I know the last function is "__call_console_drivers" .

I dissable the vmlinux code,

and grab section:

00000000800b9364 <__call_console_drivers>:
    800b9364:   27bdffd8        addiu   $sp,$sp,-40
    800b9368:   afb00010        sw      $s0,16($sp)
    800b936c:   3c108028        lui     $s0,0x8028
    800b9370:   8e107d1c        lw      $s0,32028($s0)
    800b9374:   afb10014        sw      $s1,20($sp)
    800b9378:   00808821        move    $s1,$a0
    800b937c:   afb40020        sw      $s4,32($sp)
    800b9380:   00a0a021        move    $s4,$a1
    800b9384:   afbf0024        sw      $ra,36($sp)    #save ra into SP
    800b9388:   afb3001c        sw      $s3,28($sp)
    800b938c:   12000012        beqz    $s0,800b93d8 <__call_console_drivers+74>
    800b9390:   afb20018        sw      $s2,24($sp)
    800b9394:   32323fff        andi    $s2,$s1,0x3fff
    800b9398:   3c13802a        lui     $s3,0x802a
    800b939c:   267353a0        addiu   $s3,$s3,21408
    800b93a0:   9602001c        lhu     $v0,28($s0)
    800b93a4:   30420004        andi    $v0,$v0,0x4
    800b93a8:   50400009        beqzl   $v0,800b93d0 <__call_console_drivers+6c>
    800b93ac:   8e100024        lw      $s0,36($s0)
    800b93b0:   8e020008        lw      $v0,8($s0)
    800b93b4:   50400006        beqzl   $v0,800b93d0 <__call_console_drivers+6c>
    800b93b8:   8e100024        lw      $s0,36($s0)
    800b93bc:   02002021        move    $a0,$s0
    800b93c0:   02532821        addu    $a1,$s2,$s3
    800b93c4:   0040f809        jalr    $v0
    800b93c8:   02913023        subu    $a2,$s4,$s1
    800b93cc:   8e100024        lw      $s0,36($s0)
    800b93d0:   5600fff4        bnezl   $s0,800b93a4 <__call_console_drivers+40>
    800b93d4:   9602001c        lhu     $v0,28($s0)
    800b93d8:   8fbf0024        lw      $ra,36($sp)
    800b93dc:   8fb40020        lw      $s4,32($sp)
    800b93e0:   8fb3001c        lw      $s3,28($sp)
    800b93e4:   8fb20018        lw      $s2,24($sp)
    800b93e8:   8fb10014        lw      $s1,20($sp)
    800b93ec:   8fb00010        lw      $s0,16($sp)
    800b93f0:   03e00008        jr      $ra                      # error should 
be here.
    800b93f4:   27bd0028        addiu   $sp,$sp,40



Any comment? thanks.