On 2014-08-05 09:20, Hannes Petermaier wrote:
hi folks,
i am actually trying to enable the "enhanced data area" on an 4GB emmc
device, this i've done successfully with the linux mmc-utils and the
card has after this "partitioning" 2GB user-partition.
Linux kernel deals correctly with the card.
U-Boot doesn't:
"
MMC: block number 0x301 exceeds max(0x0)
spl: mmc blk read err - 0
### ERROR ### Please RESET the board ###
"
So i debugged around and found the capacity-calculation, which i don't
fully understand.
"
if (mmc->high_capacity) {
csize = (mmc->csd[1] & 0x3f) << 16
| (mmc->csd[2] & 0xffff0000) >> 16;
cmult = 8;
} else {
csize = (mmc->csd[1] & 0x3ff) << 2
| (mmc->csd[2] & 0xc0000000) >> 30;
cmult = (mmc->csd[2] & 0x00038000) >> 15;
}
"
The else path does for my opinion the right calculation according the
mmc-specification, the "high_capacity" path i do not understand at
all, neither i found some specification for this.
In fact my 4GB card (with 2GB enhanced area) works only with "the
else" path.
my csd Registers:
MMC-card dection:
ocr : 0xc0ff8080
csd[0] : 0xd04f0132
csd[1] : 0x0f5a13ff
csd[2] : 0xffffffe7
csd[3] : 0x8a4000f1
c_size : 0x00000000003fffff
c_mult : 0x0000000000000008
U-Boot (BuR V2.0)# mmc info
Device: OMAP SD/MMC
Manufacturer ID: fe
OEM: 14e
Name: MMC04
Tran Speed: 52000000
Rd Block Len: 512
MMC version 4.41
High Capacity: Yes
Capacity: 4 TiB
Bus Width: 1-bit
any ideas ?
best regards,
Hannes
I've digged a bit deeper and found an (for me, as newbie in this)
interesting webpage:
http://www.hjreggel.net/cardspeed/special-sd.html
there i've found the key to understand the "high_capacity" path:
"...In CSD Version 2.0, the C_SIZE field was extended to 22 bit. The
C_SIZE_MULT was dropped, assuming a preset multiplier of 2^10 . The
READ_BL_LEN was kept, but the only value allowed is 9, indicating a
block length of 512 bytes."
So the code should be as following:
- if (mmc->high_capacity) {
+ if (mmc->high_capacity && mmc->read_bl_len == MMC_MAX_BLOCK_LEN) {
i'am correct in my thinking ? please some comment.
if yes - i will format a patch for this
best regards,
Hannes
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