* Early prints on different UART's for same machine type [not found] <mailman.7147.1312868034.20023.linux-arm-kernel@lists.infradead.org> @ 2011-08-09 5:56 ` Mohammed, Afzal 2011-08-10 6:37 ` Paul Walmsley 0 siblings, 1 reply; 2+ messages in thread From: Mohammed, Afzal @ 2011-08-09 5:56 UTC (permalink / raw) To: linux-arm-kernel-bounces, linux-omap; +Cc: Nori, Sekhar Hi, This is regarding board with multiple variations using an upcoming SoC from TI. Variation of the board is detected by reading EEPROM using I2C after init_machine gets invoked. In one of the variation UART# used is different. Because of this decompressor logs (and early prints) can't be captured for the board variant using this different UART#. Our solution for this problem is to use different mach-id for the board using different UART#. But this solution seems to be overkill as only to capture decompressor logs, we have to use a new machine id. As I2C will not work at the decompressor stage, I2C can't be used to detect the board type. As far as I know, ATAG is not parsed in decompressor stage and so ATAG cannot be used to determine board variant or UART#. Otherwise we will have to add capability in decompressor to parse ATAG, detect console to be used, and modify uncompress.h to select proper console for capturing decompressor logs. This seems a bad solution. Our bootloader has the capability to detect the board variant. So the best solution for us so far seems to add a new machine id, if any better solutions are possible, please let us know. Regards Afzal ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Early prints on different UART's for same machine type 2011-08-09 5:56 ` Early prints on different UART's for same machine type Mohammed, Afzal @ 2011-08-10 6:37 ` Paul Walmsley 0 siblings, 0 replies; 2+ messages in thread From: Paul Walmsley @ 2011-08-10 6:37 UTC (permalink / raw) To: Mohammed, Afzal; +Cc: linux-arm-kernel-bounces, linux-omap, Nori, Sekhar Hi On Tue, 9 Aug 2011, Mohammed, Afzal wrote: > This is regarding board with multiple variations using an upcoming SoC from TI. > Variation of the board is detected by reading EEPROM using I2C after > init_machine gets invoked. In one of the variation UART# used is different. > Because of this decompressor logs (and early prints) can't be captured for the > board variant using this different UART#. Our solution for this problem is to > use different mach-id for the board using different UART#. But this solution > seems to be overkill as only to capture decompressor logs, we have to use > a new machine id. > > As I2C will not work at the decompressor stage, I2C can't be used to detect > the board type. > > As far as I know, ATAG is not parsed in decompressor stage and so ATAG cannot > be used to determine board variant or UART#. Otherwise we will have to add > capability in decompressor to parse ATAG, detect console to be used, and > modify uncompress.h to select proper console for capturing decompressor logs. > This seems a bad solution. > > Our bootloader has the capability to detect the board variant. > > So the best solution for us so far seems to add a new machine id, if any > better solutions are possible, please let us know. You might get more feedback if you E-mail <linux-arm-kernel@lists.infradead.org>, rather than <linux-arm-kernel-bounces@lists.infradead.org>. - Paul ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2011-08-10 6:37 UTC | newest] Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <mailman.7147.1312868034.20023.linux-arm-kernel@lists.infradead.org> 2011-08-09 5:56 ` Early prints on different UART's for same machine type Mohammed, Afzal 2011-08-10 6:37 ` Paul Walmsley
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