DE10 Nano - Booting from FPGA

[Hannes]

Hello,



I am currently working on a small project for the DE10 Nano Board and setup
Pinmux for the Ethernet PHY signals. As I need the preloader to configure
the Pinmux in the HPS, I have tried to set this up based on the current
u-boot-socfpga branch. For this purpose i followed different guides on
rocketboards.org and the "AN 709: HPS SoC Boot Guide" on how to build a
bootloader and configure HPS from FPGA using EPCS64 flash memory. I could
configure SPL_TEXT_BASE=0xC0000000 and "Support booting from SPI Flash" in
menuconfig, build and create .hex file from u-boot-spl to initalize the
on-chip RAM. Problem is that the preloader does not seem to be executed.
Upon further investigation i noticed that the spl data address is not at
0XFFFF0000 as suggested by several older guides:

arm-none-eabi-readelf -S spl/u-boot-spl
There are 19 section headers, starting at offset 0x1482f4:

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk
Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0
0  0
  [ 1] .text             PROGBITS        c0000000 001000 00b5d4 00  AX  0
0 64
  [ 2] .rodata           PROGBITS        c000b5d4 00c5d4 00232b 00   A  0
0  4
  [ 3] .data             PROGBITS        c000d900 00e900 000098 00  WA  0
0  4
  [ 4] __u_boot_list     PROGBITS        c000d998 00e998 000840 00  WA  0
0  4
  [ 5] .bss              PROGBITS        c000e1d8 00f1d8 000010 00   W  0
0  4
  [ 6] .ARM.attributes   ARM_ATTRIBUTES  00000000 00f1e8 000029 00      0
0  1
  [ 7] .comment          PROGBITS        00000000 00f211 000026 01  MS  0
0  1
  [ 8] .debug_line       PROGBITS        00000000 00f237 0292fa 00      0
0  1
  [ 9] .debug_info       PROGBITS        00000000 038531 08eab7 00      0
0  1
  [10] .debug_abbrev     PROGBITS        00000000 0c6fe8 0134ca 00      0
0  1
  [11] .debug_aranges    PROGBITS        00000000 0da4b8 002948 00      0
0  8
  [12] .debug_str        PROGBITS        00000000 0dce00 010da7 01  MS  0
0  1
  [13] .debug_loc        PROGBITS        00000000 0edba7 042307 00      0
0  1
  [14] .debug_ranges     PROGBITS        00000000 12feb0 006ca0 00      0
0  8
  [15] .debug_frame      PROGBITS        00000000 136b50 007324 00      0
0  4
  [16] .symtab           SYMTAB          00000000 13de74 006a70 10     17
1244  4
  [17] .strtab           STRTAB          00000000 1448e4 00394d 00      0
0  1
  [18] .shstrtab         STRTAB          00000000 148231 0000c1 00      0
0  1


I also couldn't find that value in the menuconfig, nor could I find any
up-to-date guidelines for booting HPS preloader from FPGA. Can you tell me
if this approach is still viable and how to implement it correctly?

Best regards,

Hannes Grabmann