Hi All,
I'm working on a baremetal driver for the SDHOST controller on the RPI 3b for educational purposes (and quite an educational journey it's been).
I am now reading the card and its MBR but have found the read block command (CMD17) returns a 64 byte data block before the actual 512 bytes of the requested sector. I assume this is CRC related as I don't see it on the actual disk itself with a hex editor in windows. The only way for me to accurately read the entire sector is to increase my buffer size by the extra 64 bytes. I did not have this extra data in the other commands I've used thus far (for card init) namely, ACMD51 and CMD6 - both of which return their responses via DATA instead of the response registers. I didn't expect to see CRC data in the sector read as CRC errors seem to be handled by SDHOST itself without the need for software CRC validation.
Is this extra data CRC data? Is it unique to CMD17 or are there other commands that I'll have to handle this on?
Thanks!
Here's my output with an extra register dump and hex dump of sector 0/MBR using a buffer of 512 + 64 bytes. Note the extra 64 bytes at the beginning of the hex dump.
I'm working on a baremetal driver for the SDHOST controller on the RPI 3b for educational purposes (and quite an educational journey it's been).
I am now reading the card and its MBR but have found the read block command (CMD17) returns a 64 byte data block before the actual 512 bytes of the requested sector. I assume this is CRC related as I don't see it on the actual disk itself with a hex editor in windows. The only way for me to accurately read the entire sector is to increase my buffer size by the extra 64 bytes. I did not have this extra data in the other commands I've used thus far (for card init) namely, ACMD51 and CMD6 - both of which return their responses via DATA instead of the response registers. I didn't expect to see CRC data in the sector read as CRC errors seem to be handled by SDHOST itself without the need for software CRC validation.
Is this extra data CRC data? Is it unique to CMD17 or are there other commands that I'll have to handle this on?
Thanks!
Here's my output with an extra register dump and hex dump of sector 0/MBR using a buffer of 512 + 64 bytes. Note the extra 64 bytes at the beginning of the hex dump.
Code:
Broadcom SD Card Controller Found Card: SanDisk SD-SD128 rev8.5 sn4275228118 (manuf 05/2024) Capacity: 122008 MB High Speed: Enabled 4-bit Mode: EnabledRead SDCard 20552 Block 0:=========== REGISTER DUMP ===========SDCMD 0x00000051: CMD17 READSDARG 0x00000000SDRSP 0x00000900 0x00001133 0x7fffffff 0x0002482eSDHSTS 0x00000000:SDEDM 0x00010801: DATAMODE R/W_THRSHLD=4/4SDHCFG 0x0000000e: SLOWCARD 4bitEXT 4bitINTSDVDD 0x00000001SDHBCT 0x00000200SDHBLC 0x00000001SDTOUT 0x017d7840SDCDIV 0x00000006 (VCORE: 400Mhz / DIV: 8 = CARD: 50Mhz)=====================================00 c8 80 01 80 01 80 01 80 01 c0 01 80 03 00 00 [016]01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [032]00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [048]00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [064]33 c0 8e d0 bc 00 7c 8e c0 8e d8 be 00 7c bf 00 [080] 3 | |06 b9 00 02 fc f3 a4 50 68 1c 06 cb fb b9 04 00 [096] P hbd be 07 80 7e 00 00 7c 0b 0f 85 0e 01 83 c5 10 [112] ~ |e2 f1 cd 18 88 56 00 55 c6 46 11 05 c6 46 10 00 [128] V U F Fb4 41 bb aa 55 cd 13 5d 72 0f 81 fb 55 aa 75 09 [144] A U ] r U uf7 c1 01 00 74 03 fe 46 10 66 60 80 7e 10 00 74 [160] t F f ` ~ t26 66 68 00 00 00 00 66 ff 76 08 68 00 00 68 00 [176] & f h f v h h7c 68 01 00 68 10 00 b4 42 8a 56 00 8b f4 cd 13 [192] | h h B V9f 83 c4 10 9e eb 14 b8 01 02 bb 00 7c 8a 56 00 [208] | V8a 76 01 8a 4e 02 8a 6e 03 cd 13 66 61 73 1c fe [224] v N n f a s4e 11 75 0c 80 7e 00 80 0f 84 8a 00 b2 80 eb 84 [240] N u ~55 32 e4 8a 56 00 cd 13 5d eb 9e 81 3e fe 7d 55 [256] U 2 V ] > } Uaa 75 6e ff 76 00 e8 8d 00 75 17 fa b0 d1 e6 64 [272] u n v u de8 83 00 b0 df e6 60 e8 7c 00 b0 ff e6 64 e8 75 [288] ` | d u00 fb b8 00 bb cd 1a 66 23 c0 75 3b 66 81 fb 54 [304] f # u ; f T43 50 41 75 32 81 f9 02 01 72 2c 66 68 07 bb 00 [320] C P A u 2 r , f h00 66 68 00 02 00 00 66 68 08 00 00 00 66 53 66 [336] f h f h f S f53 66 55 66 68 00 00 00 00 66 68 00 7c 00 00 66 [352] S f U f h f h | f61 68 00 00 07 cd 1a 5a 32 f6 ea 00 7c 00 00 cd [368] a h Z 2 |18 a0 b7 07 eb 08 a0 b6 07 eb 03 a0 b5 07 32 e4 [384] 205 00 07 8b f0 ac 3c 00 74 09 bb 07 00 b4 0e cd [400] < t10 eb f2 f4 eb fd 2b c9 e4 64 eb 00 24 02 e0 f8 [416] + d $24 02 c3 49 6e 76 61 6c 69 64 20 70 61 72 74 69 [432] $ I n v a l i d p a r t i74 69 6f 6e 20 74 61 62 6c 65 00 45 72 72 6f 72 [448] t i o n t a b l e E r r o r20 6c 6f 61 64 69 6e 67 20 6f 70 65 72 61 74 69 [464] l o a d i n g o p e r a t i6e 67 20 73 79 73 74 65 6d 00 4d 69 73 73 69 6e [480] n g s y s t e m M i s s i n67 20 6f 70 65 72 61 74 69 6e 67 20 73 79 73 74 [496] g o p e r a t i n g s y s t65 6d 00 00 00 63 7b 9a 42 60 25 26 00 00 00 20 [512] e m c { B ` % &21 00 0c fe ff ff 00 08 00 00 00 b8 e4 0e 00 00 [528] !00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [544]00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [560]00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa [576] UStatistics: Posted by willdieh — Mon Oct 07, 2024 11:26 pm