From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Grinberg Date: Tue, 05 Jul 2011 10:31:47 +0300 Subject: [U-Boot] [PATCH 5/5] Warn when the machine ID isn't passed to an ARM kernel and u-boot is compiled in debug mode. The kernel cannot boot without it. In-Reply-To: <20110704203235.GI3016@harvey-pc.matrox.com> References: <20110704174541.GF3016@harvey-pc.matrox.com> <20110704180844.GC30477@titan.lakedaemon.net> <20110704185554.GH3016@harvey-pc.matrox.com> <20110704201349.GD30477@titan.lakedaemon.net> <20110704203235.GI3016@harvey-pc.matrox.com> Message-ID: <4E12BDE3.7040608@compulab.co.il> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 07/04/11 23:32, Christopher Harvey wrote: > On Mon, Jul 04, 2011 at 04:13:49PM -0400, Jason wrote: >> On Mon, Jul 04, 2011 at 02:55:54PM -0400, Christopher Harvey wrote: >>> On Mon, Jul 04, 2011 at 02:08:44PM -0400, Jason wrote: >>>> On Mon, Jul 04, 2011 at 01:45:41PM -0400, Christopher Harvey wrote: >>>>> + Hopefully there will never be this many machines. >>>>> + Can't use 0 since 0 is already used as a mach-type. */ >>>>> + gd->bd->bi_arch_number = 0xffffffff; >>>>> >>>>> gd->bd->bi_baudrate = gd->baudrate; >>>>> /* Ram ist board specific, so move it to board code ... */ >>>>> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c >>>>> index 802e833..70b3b76 100644 >>>>> --- a/arch/arm/lib/bootm.c >>>>> +++ b/arch/arm/lib/bootm.c >>>>> @@ -113,6 +113,12 @@ int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images) >>>>> printf ("Using machid 0x%x from environment\n", machid); >>>>> } >>>>> >>>>> +#ifdef DEBUG >>>>> + if(machid==0xffffffff) { >>>>> + debug("\nWarning: machid not set! Linux will not finish booting.\n\n"); >>>> s/finish/start/ ;-) >>>> >>> I'll have to disagree here. Linux will decompress and some functions >>> will run but it will eventually stop, hence will not finish. >> On further investigation, you're right, it doesn't finish >> starting/booting. Sorry for the noise. To remove all doubts, why not make it: Warning: machid not set! Linux will not be able to boot properly! >>>> Also, shouldn't the compile fail in this case (#error)? Or, at least #warn? >>>> >>> The compiler can't know what machid will be at runtime. Maybe a "would >>> you like to continue?" prompt could work. >> Since the kernel throws a nice fat error message when the MACH_TYPE >> doesn't match what it was compiled for, I don't see the point to adding >> another message at the same point in the development process. > I didn't see that message. Do you know what lines of code in the > kernel print it? Or maybe just the message itself? > If the kernel can check the value why would it need to be passed > in the first place? > >> Perhaps use the constant CONFIG_MACH_TYPE, set to 0xffffffff. Each >> board config file sets it to MACH_TYPE_WHATEVER and then you could >> do: >> >> #if CONFIG_MACH_TYPE == 0xffffffff >> #warning "Machine type not set! Linux will not finish booting!" >> #endif >> >> You could use -Werror to fail on such things. DBGFLAGS in ./config.mk >> might be a good place. >> >> If the maintainers choose to move to a menuconfig style configuration >> system, this logic could be handled in there (invalid config file). > Right now CONFIG_MACH_TYPE is only used in a few boards and isn't used > in core u-boot code, so I ignored it. I would agree that perhaps > adding a CONFIG_MACH_TYPE to u-boot would be a more elegant solution > than checking to make sure that it is a valid value before boot, but > that would be another patch. There is a patch ("arm: add CONFIG_MACH_TYPE option and documentation") pending that adds CONFIG_MACH_TYPE (in case Jason missed it) as the formal config option. But, again, it can be _runtime_ configurable, so you _can't_ fail the compilation. -- Regards, Igor.