2017-09-05 16:12 GMT+03:00 Alexander Graf <[email protected]>:
>
>
> On 05.09.17 15:02, Matwey V. Kornilov wrote:
>>
>> 2017-09-05 16:00 GMT+03:00 Alexander Graf <[email protected]>:
>>>
>>>
>>> On 05.09.17 14:58, Matwey V. Kornilov wrote:
>>>>
>>>>
>>>> Still no luck. No signal at video, no text in console after EFI stub.
>>>> Any ideas why?
>>>>
>>>
>>> Can you try to make earlycon work? I'm sure someone has the magic
>>> parameters
>>> for it somewhere...
>>
>>
>> Indeed. But they don't work either. Ones which should is
>> earlycon=uart8250,mmio32,0xff130000
>
>
> That is very odd. Usually earlycon works. The only case I've found where it
> was unintuitively broken was when U-Boot ran in EL3, but I assume you do
> have ATF running somewhere, right?

It is supposed to be so.

>
> What you can still try is to recover the kernel log from RAM. For that, boot
> up the system, then reset (don't power cycle, use the reset button if
> available, otherwise use the reset line on the jtag port if available).
> After reset, you should get back to U-Boot. There, run "bdinfo" to find out
> the base offset of RAM.

What is the offset here?

=> bdinfo
arch_number = 0x00000000
boot_params = 0x00000000
DRAM bank   = 0x00000000
-> start    = 0x00200000
-> size     = 0x7FE00000
current eth = unknown
ip_addr     = <NULL>
baudrate    = 1500000 bps
TLB addr    = 0x7FFF0000
relocaddr   = 0x7FF41000
reloc off   = 0x7FD41000
irq_sp      = 0x7DF37660
sp start    = 0x7DF37660
Early malloc usage: 460 / 800
fdt_blob = 000000007df37670

>
> Then do "nm vmlinux | grep log_buf" on the vmlinux file to the kernel you
> executed. You may have to extract it first, as it comes gzip'ed by default.
> In there you will find Linux virtual addresses for log_buf locations. IIRC
> __log_buf is the one you want. Remove the high 1-bits from that address,
> then add the RAM offset to it. That *should* hopefully be the offset into
> RAM for the dmesg buffer.
>
> With that address, try to "md.b" its contents from the U-Boot command line.
> With a bit of luck you can spot something. If not we either had kASLR hit or
> didn't get as far as writing a dmesg buffer...
>
>
> Alex



-- 
With best regards,
Matwey V. Kornilov
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