before I ask this question, I do google it, and search it on community, and read the "i.MX 6Quad_6Dual Reference Manual (Rev O)" PDF file.
the two post I read from community:
According table8-22 & table 8-25 in "i.MX 6Quad_6Dual Reference Manual (Rev O)" PDF, we should able to boot from SPI,
I soldered the SPI device to the board using the pin configuration as follows:
BOOT_CFG1[7:4] = 0011 (Boot from Serial ROM).
BOOT_CFG4[5:4] = 01 (CS#1).
BOOT_CFG4 = 1
BOOT_CFG4[2:0] = 000 (ECSPI-1).
and attach SPI chip pins like below:
CS -> EIM_D19
MISO -> EIM_D17
MOSI -> EIM_D18
CLK -> EIM_D16
but device won't boot, I measure the CLK pin at boot time, found "no clock signal" was sent.
it seems it get into serial-download mode, and I can use imx_usb_loader send u-boot from usb otg.
if I switch boot from eMMC, we still can read/write SPI by
"sf probe 1"
"sf read 10800000 0x0 0x100000"
"sf write 10800000 0x0 0x100000"
it seems SPI works great and perfect.
could anyone give me some hint or tips about this problem? I'll be appreciated.