From: robin.murphy@arm•com (Robin Murphy)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v1 3/4] arm64: Add arm64 kexec support
Date: Thu, 21 Jul 2016 11:50:42 +0100 [thread overview]
Message-ID: <5790A902.6070601@arm.com> (raw)
In-Reply-To: <20160721103120.GB20559@leverpostej>
On 21/07/16 11:31, Mark Rutland wrote:
[...]
>>>> +
>>>> +> > > > if (*p == 0)
>>>> +> > > > > > return 0;
>>>> +
>>>> +> > > > errno = 0;
>>>> +
>>>> +> > > > v = strtoull(p, NULL, 0);
>>>> +
>>>> +> > > > if (errno)
>>>> +> > > > > > return 0;
>>>> +
>>>> +> > > > return v;
>>>> +}
>>>
>>> It looks like the purgatory code expects angel SWI as the earlycon,
>>
>> Maybe you saw the debug_brk macro in entry.S? I should remove
>> that and just loop.
>
> Ah, sorry. For some reason I got that confused with the sink code. My
> bad.
>
> Now I see that's assuming an 8-bit MMIO register.
>
>>> whereas many other earlycons exist (with pl011 being extremely popular).
>>> Regardless, if we assume a particular UART type, we should explicitly
>>> verify that here. Otherwise the purgatory code will likely bring down
>>> the system, and it will be very painful to debug.
>>>
>>> Please explicitly check for the supported earlycon name.
>>
>> Purgatory just writes bytes to the address given. Are there
>> UARTs that don't have TX as the first port?
>
> I'm not sure, but it's certainly possible. The generic earlycon binding
> doesn't guarantee that the first address is a TX register. Even if they
> don't exist today, they could in a month's time, so I don't think we
> should assume anything.
The Exynos UART (drivers/tty/serial/samsung.c) is one which comes to
mind as definitely existing, and on arm64 systems to boot. The TX
register is at offset 0x20 there.
Robin.
next prev parent reply other threads:[~2016-07-21 10:50 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-19 23:28 [PATCH v1 0/4] arm64 kexec-tools patches Geoff Levand
2016-07-19 23:28 ` [PATCH v1 2/4] kexec: Add common device tree routines Geoff Levand
2016-07-22 7:19 ` AKASHI Takahiro
2016-07-27 18:11 ` Geoff Levand
2016-07-19 23:28 ` [PATCH v1 3/4] arm64: Add arm64 kexec support Geoff Levand
2016-07-20 15:39 ` Mark Rutland
2016-07-20 19:19 ` Geoff Levand
2016-07-21 10:31 ` Mark Rutland
2016-07-21 10:50 ` Robin Murphy [this message]
2016-07-21 21:49 ` Geoff Levand
2016-07-22 4:08 ` Pratyush Anand
2016-07-22 5:33 ` AKASHI Takahiro
2016-07-22 9:54 ` Mark Rutland
2016-07-22 10:03 ` Robin Murphy
2016-07-22 13:56 ` Pratyush Anand
2016-07-22 17:59 ` Robin Murphy
2016-07-25 21:56 ` Geoff Levand
2016-07-20 17:53 ` Pratyush Anand
2016-07-20 20:33 ` Geoff Levand
2016-07-20 20:54 ` [PATCH v1.2 " Geoff Levand
2016-07-22 7:12 ` AKASHI Takahiro
2016-07-26 0:37 ` Geoff Levand
2016-07-25 14:28 ` Ruslan Bilovol
2016-07-25 20:50 ` Geoff Levand
2016-07-26 1:36 ` Ruslan Bilovol
2016-07-26 8:16 ` AKASHI Takahiro
2016-07-26 21:26 ` Ruslan Bilovol
2016-07-26 21:54 ` Geoff Levand
2016-07-19 23:28 ` [PATCH v1 4/4] arm64: Add support for binary image files Geoff Levand
2016-07-19 23:28 ` [PATCH v1 1/4] kexec: (bugfix) calc correct end address of memory ranges in device tree Geoff Levand
2016-07-27 22:45 ` Thiago Jung Bauermann
2016-07-27 23:23 ` Russell King - ARM Linux
2016-07-28 23:54 ` Thiago Jung Bauermann
2016-07-29 8:27 ` Russell King - ARM Linux
2016-07-29 17:12 ` Geoff Levand
2016-07-29 17:23 ` Russell King - ARM Linux
2016-08-01 4:52 ` AKASHI Takahiro
2016-09-06 0:29 ` Memory range end be inclusive or exclusive? " AKASHI Takahiro
2016-10-31 8:50 ` AKASHI Takahiro
2016-11-07 8:17 ` Simon Horman
2016-07-20 4:30 ` [PATCH v1 0/4] arm64 kexec-tools patches AKASHI Takahiro
2016-07-26 23:05 ` Simon Horman
2016-07-27 5:57 ` AKASHI Takahiro
2016-07-28 18:09 ` Geoff Levand
2016-07-29 0:31 ` Simon Horman
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