formating sd on VM/Mac doesn't look like it works. (stuck busy bit?)

[cire831]

blk_id 0 looks funny.

somebody over wrote the boot sector, we don't know who.

zot (3): xdw -N 10K /dev/mmcblk0 
000000 168c000c 87298027 00000604 0ac4b83d  >....'.).....=...<
000010 00000619 27188080 fefeffff fefefeff  >.......'........<
000020 00000000 80808080 00008080 00000003  >................<
000030 002c0288 a2d9716c d946035b 51e14be7  >..,.lq..[.F..K.Q<
000040 6fc29ff0 0e108183 aa100001 0003aaaa  >...o............<
000050 00080000 dc052045 0040bfcc a90d062f  >....E ....@./...<
000060 b6a642c7 f23ca8c0 d6c85000 100ebdbf  >.B....<..P......<
000070 f78fe56d 2c011850 0000d2fb fbb4c46b  >m...P..,....k...<
000080 e5d5e258 865c83b0 5a854cfb 3047d669  >X.....\..L.Zi.G0<
000090 f9a8d009 39969c77 01f01cfe f08f5ee9  >....w..9.....^..<
0000a0 c4875fe3 a0cd1d3a 48db1a53 ca395461  >._..:...S..HaT9.<
0000b0 e7f5f02f 345d1120 39b3dbe6 5497472a  >/... .]4...9*G.T<
0000c0 8be61a70 c9aa892e 333b3067 0cc707ba  >p.......g0;3....<
0000d0 d8efb19d 1c6c61d6 0727d992 b257fa23  >.....al...'.#.W.<
0000e0 f8a76fcb 3b4dceaa 90974d52 702a29b3  >.o....M;RM...)*p<
0000f0 ca8dc3ca 8bab3d7d eb1bfed4 d9bf9216  >....}=..........<
000100 4fd8bb3c 7e2be4dd 57f9f120 cec18897  ><..O..+~ ..W....<
000110 d115bc32 e20c38f5 55a3e094 39835fda  >2....8.....U._.9<
000120 0f20dc08 d4ebf4b4 902d81d3 951f1940  >.. .......-.@...<
000130 3c822f6d f6675f42 5c00ff6c 6b9e1fa8  >m/.<B_g.l..\...k<
000140 69f84b7f b13e9373 b8b51d77 cb46a3e5  >.K.is.>.w.....F.<
000150 81c7ee11 c311d6fa 89b29355 c23253dd  >........U....S2.<
000160 5f7357d2 77f8442d adc63da5 f9e0aa2e  >.Ws_-D.w.=......<
000170 4763aa16 db631923 bbce1ff0 8b556b5d  >..cG#.c.....]kU.<
000180 ea9ab245 8bbfdb4d f01ccb68 2b7b5514  >E...M...h....U{+<
000190 b3ba25fb 54c434d2 a88c43b4 f9cfb1e1  >.%...4.T.C......<
0001a0 f891eb3d 46fd368b de49dece 525ad538  >=....6.F..I.8.ZR<
0001b0 7fc7a1a3 7bad1fc3 52a8e014 173f3eb2  >.......{...R.>?.<
0001c0 43cc7888 3d5df4a8 d5547b0e 406a0d35  >.x.C..]=.{T.5.j@<
0001d0 ad489a65 549e4dde b9e71827 50457dee  >e.H..M.T'....}EP<
0001e0 a3d3cffe b93cb90b 21a7fb24 39d8dd86  >......<.$..!...9<
0001f0 8f335e6f 7fc55371 25c85a1a b061d285  >o^3.qS...Z.%..a.<

should be something like:

000000 6d9058eb 2e73666b 00746166 00200802  >.X.mkfs.fat... .<
000010 00000002 0000f800 007a003e 00000000  >........>.z.....<
000020 00762c00 00001d7d 00000000 00000002  >.,v.}...........<
000030 00060001 00000000 00000000 00000000  >................<
000040 13290180 5489a4f3 47344741 20202020  >..)....TAG4G    <
000050 41462020 20323354 1f0e2020 ac7c77be  >  FAT32   ...w|.<
000060 0b74c022 bb0eb456 10cd0007 32f0eb5e  >".t.V.......^..2<
000070 cd16cde4 54feeb19 20736968 6e207369  >.......This is n<
000080 6120746f 6f6f6220 6c626174 69642065  >ot a bootable di<
000090 202e6b73 656c5020 20657361 65736e69  >sk.  Please inse<
0000a0 61207472 6f6f6220 6c626174 6c662065  >rt a bootable fl<
0000b0 7970706f 646e6120 72700a0d 20737365  >oppy and..press <
0000c0 20796e61 2079656b 74206f74 61207972  >any key to try a<
0000d0 6e696167 2e2e2e20 000a0d20 00000000  >gain ... .......<
0000e0 00000000 00000000 00000000 00000000  >................<
*
000140 deedbeaf 00003b22 00003c21 00003c22  >....";..!<.."<..<
000150 00003c31 00003c32 00004039 0000403a  >1<..2<..9@..:@..<
000160 00762bf9 00000000 00000000 00000000  >.+v.............<
000170 00000000 00000000 00000000 00000000  >................<
000180 00000000 deedbeaf 0000ec1e 00000000  >................<
000190 00000000 00000000 00000000 00000000  >................<
*
0001f0 00000000 00000000 00000000 aa550000  >..............U.<

[cire831]

when the "bad" sd is loaded on a dev board. it sees sector 0 correctly. And the data is correct. We don't know why the read on the linux box got the wrong data.

[cire831]

we have re-read the "bad" sd and the LInux box now sees the correct data.

We do not have an explanation for why the weird read happened.

[cire831]

the sd in question won't format using mkdosfs. complains about a dirty bit being set. When we try to clear it it says it did it but then mkdosfs complains about it being set. Something ain't right.

[cire831]

this may be some strange anomoly with zot (linux 14.04). Plugged in a fresh 4G (factory format) and tried to do a mkdosfs on it. Got the complaint about mounted file system (dirty bit set).

Rebooted and the same card formats fine.