how to access rpmb partition with HAL_MMC_xx functions

[mzenn.280]

I am using STM32H735AGI6 on a custom board with an KLM8G1GETF eMMC

I am reading JEDEC Standard No. 84-B451

I want to start reading counter: std says "The counter read sequence is initiated by Write Multiple Block command, CMD25. Prior to CMD25, the block count is set to 1 by CMD23"

Prob 1: There is only 1 block to write but in HAL_MMC_WriteBlocks_DMA I find

if (NumberOfBlocks > 1U)

{

hmmc->Context = (MMC_CONTEXT_WRITE_MULTIPLE_BLOCK | MMC_CONTEXT_DMA);

/* Write Multi Block command */

errorstate = SDMMC_CmdWriteMultiBlock(hmmc->Instance, add);

}

else

{

hmmc->Context = (MMC_CONTEXT_WRITE_SINGLE_BLOCK | MMC_CONTEXT_DMA);

/* Write Single Block command */

errorstate = SDMMC_CmdWriteSingleBlock(hmmc->Instance, add);

}

so it will send "write single block"

Prob 2: As you can see, before SDMMC_CmdWriteMultiBlock, it does not send CMD23.

Moreover, if you search for SDMMC_CMD_SET_BLOCK_COUNT (aka CMD23), you find only the #define

Can you help me?

[Tesla DeLorean]

Add the function / code needed to communicate the expected length, makes parts like those from SanDisk faster.

[mzenn.280]

I don't understand

I should call HAL_MMC_WriteBlocks_DMA(mmc, my_read_counter_command,0,1), but:

1) the func will use CMD24, not CMD25

2) CMD23 is never used

Can you point me to examples using CMD23?

[mzenn.280]

no help?

[mzenn.280 · Accepted solution]

to whom it may concern:

First of all, you must add a function that implements cmd23

Next you must implement  read/write functions that mimics HAL_MMC_ReadBlocks_DMA and HAL_MMC_WriteBlocks_DMA but they:

1) always use multiple block commands

2) do not send cmd12 (stop command), you must modify HAL_MMC_IRQHandler

Now you can do all the operations on rpmb