SD card not detected on a M0 core

[takayuki-imada]

Hi,

Thanks a lot for providing this u-boot porting to BL808.

I have followed the instruction described in https://github.com/openbouffalo/u-boot/releases/tag/bl808-2023-02-19 to use this u-boot porting on my Ox64 board.
(A compiler I used can be found at https://musl.cc/riscv32-linux-musl-cross.tgz.)

However, u-boot running on top of the M0 core cannot detect an inserted SD card on my board.

=> mmc list
mmc@20060000: 0
=> mmc info
=>

I have enabled the logging functionality of u-boot, and an obtained result indicates that mmc commands with "SD_CMD_APP_SEND_SCR" return some errors.

=> mmc dev
CMD_SEND:0
                ARG                      0x00000000
                MMC_RSP_NONE
CMD_SEND:8
                ARG                      0x000001aa
                MMC_RSP_R1,5,6,7         0x000001aa
CMD_SEND:55
                ARG                      0x00000000
                MMC_RSP_R1,5,6,7         0x00000120
CMD_SEND:41
                ARG                      0x40300000
                MMC_RSP_R3,4             0x00ff8000
...
...
CMD_SEND:55
                ARG                      0x00000000
                MMC_RSP_R1,5,6,7         0x00000120
CMD_SEND:41
                ARG                      0x40300000
                MMC_RSP_R3,4             0xc0ff8000
CMD_SEND:2
                ARG                      0x00000000
                MMC_RSP_R2               0x02544d53
                                         0x41303447
                                         0x1135d3d5
                                         0x3900d400

                                        DUMPING DATA
                                        000 - 02 54 4d 53
                                        004 - 41 30 34 47
                                        008 - 11 35 d3 d5
                                        012 - 39 00 d4 00
CMD_SEND:3
                ARG                      0x00000000
                MMC_RSP_R1,5,6,7         0x12340500
CMD_SEND:9
                ARG                      0x12340000
                MMC_RSP_R2               0x400e0032
                                         0x5b590000
                                         0x1d177f80
                                         0x0a400000

                                        DUMPING DATA
                                        000 - 40 0e 00 32
                                        004 - 5b 59 00 00
                                        008 - 1d 17 7f 80
                                        012 - 0a 40 00 00
CMD_SEND:7
                ARG                      0x12340000
                MMC_RSP_R1,5,6,7         0x00000700
CMD_SEND:55
                ARG                      0x12340000
                MMC_RSP_R1,5,6,7         0x00000920
CMD_SEND:51
                ARG                      0x00000000
                RET                      -70
CMD_SEND:51
                ARG                      0x00000000
                RET                      -110
CMD_SEND:51
                ARG                      0x00000000
                RET                      -110
CMD_SEND:51
                ARG                      0x00000000
                RET                      -110
mmc_init: -110, time 219

On the other hand, I found that u-boot running on top of the D0 core which is built for buildroot (https://github.com/openbouffalo/buildroot_bouffalo) can correctly detect the SD card. Therefore, my Ox64 board and SD card seem fine.

=> mmc list
mmc@20060000: 0 (SD)

=> mmc info
Device: mmc@20060000
Manufacturer ID: 2
OEM: 544d
Name: SA04G
Bus Speed: 50000000
Mode: SD High Speed (50MHz)
Rd Block Len: 512
SD version 3.0
High Capacity: Yes
Capacity: 3.6 GiB
Bus Width: 4-bit
Erase Group Size: 512 Bytes

Many thanks,

--
Takayuki