This change enables at91 systems to boot from high capacity SD cards. It also fixes a few minor violations of the SD protocol, such as running the bus at high speed during the card identification sequence. The sdcard_init() routine now probes for SDHC cards so that later read requests can make needed adjustments between block and byte offsets based on card type. There is a new MCI_readblocks() function that takes block number and block count parameters instead of byte-offset values. Using this routine, boot loader code can load a kernel from any location on an SDHC or standard SD card. The old MCI_read() interface remains unchanged so that existing customized boot loader code will still keep working without changes. Using this routine, boot loaders can load a kernel from anywhere in the first 4GB of an SDHC card (or of course any location on a standard SD card). A new sdcard_use4wire() routine allows boot loaders to request 4-bit transfers; it should be called after sdcard_init(). The sdcard_init() routine no longer assumes the hardware is 4-wire capable and by default sets things up for 1-bit transfers. Fix: This patch should apply cleanly to any FreeBSD from 6.2 through -current. How-To-Repeat: n/a
A commit references this bug: Author: ian Date: Sat Jul 26 04:16:05 UTC 2014 New revision: 269113 URL: http://svnweb.freebsd.org/changeset/base/269113 Log: Enable at91 systems to boot from high capacity SD cards. This also fixes a few minor violations of the SD protocol, such as running the bus at high speed during the card identification sequence. The sdcard_init() routine now probes for SDHC cards so that later read requests can make needed adjustments between block and byte offsets based on card type. There is a new MCI_readblocks() function that takes block number and block count parameters instead of byte-offset values. Using this routine, boot loader code can load a kernel from any location on an SDHC or standard SD. The old MCI_read() interface remains unchanged so that existing customized boot loader code will still keep working without changes. Using this routine, boot loaders can load a kernel from anywhere in the first 4GB of an SDHC card (or of course any location on a standard SD card). A new sdcard_use4wire() routine allows boot loaders to request 4-bit transfers; it should be called after sdcard_init(). The sdcard_init() routine no longer assumes the hardware is 4-wire capable and by default sets things up for 1-bit transfers. (4-wire mode is unreliable on at91rm9200, works on later SoCs.) PR: 155894 Submitted by: me. years ago. Changes: head/sys/boot/arm/at91/libat91/mci_device.h head/sys/boot/arm/at91/libat91/sd-card.c head/sys/boot/arm/at91/libat91/sd-card.h