From: Angelo Dureghello <angelo@sysam.it>
To: linux-mmc@vger.kernel.org
Subject: emmc 4.4x fast boot question
Date: Wed, 22 Apr 2015 15:11:24 +0200 [thread overview]
Message-ID: <55379DFC.4040907@sysam.it> (raw)
hi experts,
trying to use imx6q "eMMC Fast Boot" mode without success. Can't
get any clarification from freescale still, so i try here.
From the imx6q boot flow diagram seems there can be some gain using it.
Once studying on the Micron eMMC i have connected to imx6q, (as per
TN-52-06: Booting from Embedded MMC - JEDEC 4.41 online pdf) i see
this mode is just called "boot mode" or "alternate boot mode", and seems
to allow to boot from SLC mmcblk0boot0 or mmcblk0boot1
partitions setting EXT_CSD[179] partition to 1 or 2 in bits 3to5.
In this way i can boot from mmcblk0boot0. but if i enable the hw
imx6q GPIO BOOT_CFG1[4] "Fast Boot" mode, i cannot boot anymore.
If i look signal with scope, booting i don't see the initial
CMD pulled low as should be for the Boot mode.
If i enable imx6q "fast boot" (BOOT_CFG1[4]) i just see a
continuos and long train of bits on both CMD and CLK from the reset.
So i can boot from special SLC mmcblk0boot0 but without imx6
"Fast Boot" enabled. So i am trying to understand why this Fast Boot
feature (BOOT_CFG1[4] set) can't be used.
In case you can give any help on this it will be really appreciated.
Best regards,
Angelo Dureghello
reply other threads:[~2015-04-22 13:18 UTC|newest]
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