[U-Boot] [issue report] mainline u-boot was stuck before booting kernel

[Ziyuan Xu]

Hi All,

I'm sorry to tell you that I failed to boot linux kernel with the 
mainline u-boot on rk3288 board(both evb-rk3288 & fennec-rk3288). It was 
stuck in cleanup_before_linux() before jumping to linux, and the 
boot_stage_flag is BOOTSTAGE_ID_BOOTM_HANDOFF.

## Current stack ends at 0x7df638b0 *  kernel: cmdline image address = 
0x02000000
## No init Ramdisk
    ramdisk start = 0x00000000, ramdisk end = 0x00000000
## No Flattened Device Tree
Continuing to boot without FDT
Initial value for argc=3
Final value for argc=3
using: ATAGS
## Transferring control to Linux (at address 02000000)...

Starting kernel ...

With the further investigation, it never returnned back from 
invalidate_dcache_all(). I mean that I can't reach stage 4 as below.

cleanup_before_linux
     ==>cleanup_before_linux_select
         ==>1.disable_interrupts
         ==>2.dcache_disable
         ==>3.invalidate_dcache_all
         ==>4.icache_disable

Debug further, invalidate_dcache_all  invalidate all cache one-by-one 
which cache type is DATA_ONLY, INSTRUCTION_DATA or UNIFIED. And 
invalidate way from one set to another set in order. The problem is that 
the PC ran away in invalidate way loop  [cache level L1!!!].

I add some serial output code in __v7_flush_dcache_all to figure out the 
bog.
I expect:
Print the value of r9 in sequence, e.g 0x7f, 0x7e, 0x7d..... 0x01, 0x00 
(hex)
In fact, print the value of r9 in sequence at first, but print 
unexpected value afterwards.   e.g 0x7f, 0x7e, 0x7d, ..,0x73, 0x40, 
0x85,....

ENTRY(__v7_flush_dcache_all)
[snip]
loop1:
     mov    r9, r7                @ create working copy of max index
loop2:
+      stmfd    sp!, {r0}
+      ldr     r0, =0xff690000
+      str     r9, [r0]
+      ldmfd    sp!, {r0}
  ARM(    orr    r11, r10, r4, lsl r5    )    @ factor way and cache 
number into r11
  THUMB(    lsl    r6, r4, r5        )
  THUMB(    orr    r11, r10, r6        )    @ factor way and cache 
number into r11
  ARM(    orr    r11, r11, r9, lsl r2    )    @ factor index number into r11
  THUMB(    lsl    r6, r9, r2        )
  THUMB(    orr    r11, r11, r6        )    @ factor index number into r11
     mcr    p15, 0, r11, c7, c14, 2        @ clean & invalidate by set/way
     subs    r9, r9, #1            @ decrement the index
     bge    loop2
     subs    r4, r4, #1            @ decrement the way
     bge    loop1
skip:
ENDPROC(__v7_flush_dcache_all)

I don't have the jtag, hence I can't address the current pc. I have no 
doubt that if any glitches in __v7_flush_dcache_all, I reviewed several 
times, also copy kernel's implement to here. :-( No effect.
A more interesting thing is that Sandy had report it.  He and I have 
similar problem. Everything work fine after I applied his patches, or 
disable dcache(active CONFIG_SYS_DCACHE_OFF).
@Stany, I'm sorry that I disable dcache during hack.. That was a mistake:-(

@Simon & hieko,
Can you boot linux with the mainline u-boot? have a try?