1 ==================================
2 SD and MMC Block Device Attributes
3 ==================================
4
5 These attributes are defined for the block dev
6 SD or MMC device.
7
8 The following attributes are read/write.
9
10 ======== ==============
11 force_ro Enforce read-o
12 ======== ==============
13
14 SD and MMC Device Attributes
15 ============================
16
17 All attributes are read-only.
18
19 ====================== ==============
20 cid Card Identific
21 csd Card Specific
22 scr SD Card Config
23 date Manufacturing
24 fwrev Firmware/Produ
25 (SD and MMCv1
26 hwrev Hardware/Produ
27 (SD and MMCv1
28 manfid Manufacturer I
29 name Product Name (
30 oemid OEM/Applicatio
31 prv Product Revisi
32 (SD and MMCv4
33 serial Product Serial
34 erase_size Erase group si
35 preferred_erase_size Preferred eras
36 raw_rpmb_size_mult RPMB partition
37 rel_sectors Reliable write
38 ocr Operation Cond
39 dsr Driver Stage R
40 cmdq_en Command Queue
41
42 1 => e
43 ====================== ==============
44
45 Note on Erase Size and Preferred Erase Size:
46
47 "erase_size" is the minimum size, in
48 operation. For MMC, "erase_size" is t
49 reported by the card. Note that "eras
50 to trim or secure trim operations wher
51 always one 512 byte sector. For SD, "
52 if the card is block-addressed, 0 othe
53
54 SD/MMC cards can erase an arbitrarily
55 including the whole card. When erasin
56 be desirable to do it in smaller chunk
57
58 1. A single erase command will ma
59 the card wait. This is not a
60 is being erased, but erasing o
61 I/O for another partition on t
62 duration of the erase - which
63 minutes.
64 2. To be able to inform the user
65 3. The erase timeout becomes too
66 useful. Because the erase tim
67 which is multiplied by the siz
68 the value can end up being sev
69 areas.
70
71 "erase_size" is not the most efficient
72 (especially for SD where it is just on
73 hence "preferred_erase_size" provides
74 size for erasing large areas.
75
76 For MMC, "preferred_erase_size" is the
77 erase size if a card specifies one, ot
78 based on the capacity of the card.
79
80 For SD, "preferred_erase_size" is the
81 size specified by the card.
82
83 "preferred_erase_size" is in bytes.
84
85 Note on raw_rpmb_size_mult:
86
87 "raw_rpmb_size_mult" is a multiple of
88
89 RPMB size in byte is calculated by usi
90
91 RPMB partition size = 128kB x
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