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AW: Accessing SDHC Cards with 8 GB
- From: "Richard Rauch" <rrauch at itrgmbh dot de>
- To: <ecos-discuss at ecos dot sourceware dot org>
- Date: Tue, 28 Jan 2014 11:07:47 +0100
- Subject: AW: Accessing SDHC Cards with 8 GB
- Authentication-results: sourceware.org; auth=none
- References: <00fc01cf1c09$ec4f7f30$c4ee7d90$ at itrgmbh dot de>
Maybe I found an answer (partially) right now.
I am always formatting SDCards ny usage of Windows (I have not verified with Linux, because our customers rarely using Linux)
I discovered this:
when a SD Card less than 8GB is formatted, it is formatted in a more standard way.
In this case in first sector there is a valid MBR with a valid partition table.
When a SD Card has a size >= 8GB, it is formatted differently. No MBR is generated. In Sector 0 there is located already Bootsector with BPB.
Unfortunately eCos do not know about this. When mounting the SD Card, it tries to interpret the BPB as MBR.
What I do not know right now: Do I have a unique criteria to decide, if first sector needs to be interpreted as MBR or as boot sector already.
And, what would be the best position in eCos driver hierarchy, to code such a decision.
Or maybe, somewhere a solution is already available?
Thanks again
Richard
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