I tried to set the fuses of an i.MX6UL so, that it boots from eMMC.
Thus, I have worked out these bits for BOOT_CFG[1-4] according to the i.MX6UL Reference Manual:
01101101 11001000 (00000000) 00000000 = 0x6dc80000
I have burnt these bits in U-BOOT using the following line:
fuse prog 0 5 0x6dc80000
As far as I know, the processor also needs bank 0 word 6: BT_FUSE_SEL set to 1, to boot according to the fuse settings?
Thus I also performed:
fuse prog 0 6 0x00000010
The thing now is, that I broke the board. I cannot boot anymore.
I would like to know if I have done everything right, especially calculating the bits 0x6dc80000 and 0x00000010 ?
Thanks in Advance!
The BOOT_CFG bits I wanted to set are following (see UL Reference p. 208: Table 5-6. MMC/eMMC Boot Fusemap):
BOOT_CFG1[7,6,5] to select eMMC.
BOOT_CFG1 to set normal mmc speed.
BOOT_CFG1 (Disable fast boot acknowledge, as we did not enable fast boot)
BOOT_CFG1: 0 => no power cycle.
BOOT_CFG1: 1: Loopback Clk Src: direct.
BOOT_CFG2[7,6,5]: 110 ... 8 bit DDR.
BOOT_CFG2[4,3]: 01 ... eSDHC2
BOOT_CFG2: 0 ... 400MHz
BOOT_CFG2: 0 ... 3.3V SD Voltage.
Rest is 0. (CFG3 is reserved and CFG4 is all 0)