Question about the IDF compatibility issue with Zephyr project

[rolandma]

I spent a lot time on the zephyr project trying to get my ESP32-wroom-32D working with the zephyr samples, but only got the hello-world to run on my dev kit.
It seems to me that the linker script has some problem in the zephyr project for the ESP32, and it generates a big binary file that when using esptool.py to flash, always has this bigger than 16 segments failure.

Who knows any detail about the linker script? It will be a huge benefit for ESP if the zephyr project can run on ESP32.

[ESP_Angus]

Hi rolandma,

Zephyr is separate to IDF, as far as I know the only shared parts are the gcc toolchain and esptool.py (neither of which are part of IDF, either).

There's not a lot of Zephyr Project users on this forum, so you may have more success posting on the Zephyr Project GitHub issues or Their Slack/Mailing list.

Sorry I can't be of more assistance.


Angus

[rolandma]

Thanks Angus, I did ask on Zephyr project, and they are not very interested in ESP32. I tried a lot and managed to get several examples on zephyr project compiled but only the 'hello-world' example will be able to flash onto my esp32-wroom-32d dev kit, all others failed. I would like to help some hints for the possible problem and further could contribute to the esp32 family.

[rolandma]

Hi Angus,
I attached 3 files, one is zephyr.elf, I renamed it to zephyr.txt, and another is linker.cmd, I renamed it as linker.txt. and then the linker.ld from soc, which I renamed as linker.ld.txt.

I don't know if those are helpful or not.

Thanks for your help.
Roland

[WiFive]

I think esp32 is still barely supported on zephyr. Only uart,gpio,i2c are listed, no networking. I'm not sure exactly how that relates to successful build with binary issues but...

[rolandma]

So any effort will be waste of time? because most accessories are not available? I need the WiFi support for my project.

[ESP_Angus]

Hi Roland,

Thanks for attaching the files. I downloaded them, but this ELF seems to convert to a .bin file OK:

Code: Select all

$ esptool.py --chip esp32 elf2image ./zephyr.elf 
esptool.py v2.9-dev
$ esptool.py --chip esp32 image_info zephyr.bin
esptool.py v2.9-dev
Image version: 1
Entry point: 40080788
8 segments

Segment 1: len 0x0006c load 0x3ffb0000 file_offs 0x00000018 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 2: len 0x00014 load 0x3ffb006c file_offs 0x0000008c [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 3: len 0x00078 load 0x3ffb0080 file_offs 0x000000a8 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 4: len 0x00254 load 0x3ffb00f8 file_offs 0x00000128 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 5: len 0x00400 load 0x40080000 file_offs 0x00000384 [IRAM]
Segment 6: len 0x00100 load 0x40080400 file_offs 0x0000078c [IRAM]
Segment 7: len 0x0006c load 0x40080500 file_offs 0x00000894 [IRAM]
Segment 8: len 0x02be8 load 0x4008056c file_offs 0x00000908 [IRAM]
Checksum: 25 (valid)
Validation Hash: ddaee29470b8e20342bc5072d8e9417d4ac72bfab6eac9ddda696c7b486f2fff (valid)

Does this not work for you? Can you post the esptool command line and output that you get?

I need the WiFi support for my project.

My understanding is the same as WiFive's, Zephyr on ESP32 does not support Wi-Fi.

To my knowledge the only third party RTOS project (aside from ESP-IDF) with Wi-Fi support on ESP32 is RIOT: https://doc.riot-os.org/group__cpu__esp ... 2_features (note that I haven't looked any further than this docs page, need to check with RIOT community about the details if you're interested in this.)

[rolandma]

Hi Angus,

Thanks a lot for your help.
I saw a lot of support for ESP32 from AliOS, does that have Wifi support? I can't use RIOT unfortunately.

[rolandma]

If I modify the limit segments from 16 to 17, and do the same elf2image, I get this:
$ esptool.py --chip esp32 image_info ./zephyr.
bin
esptool.py v2.9-dev
Image version: 1
Entry point: 400710b0
17 segments

Segment 1: len 0x000c0 load 0x3ffae000 file_offs 0x00000018 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 2: len 0x00054 load 0x3ffae0c0 file_offs 0x000000e0 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 3: len 0x00038 load 0x3ffae114 file_offs 0x0000013c [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 4: len 0x00060 load 0x3ffae14c file_offs 0x0000017c [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 5: len 0x00014 load 0x3ffae1ac file_offs 0x000001e4 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 6: len 0x00028 load 0x3ffae1c0 file_offs 0x00000200 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 7: len 0x00040 load 0x3ffae1e8 file_offs 0x00000230 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 8: len 0x00060 load 0x3ffae240 file_offs 0x00000278 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 9: len 0x00118 load 0x3ffae2a0 file_offs 0x000002e0 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 10: len 0x038f4 load 0x3ffae3b8 file_offs 0x00000400 [BYTE_ACCESSIBLE, DRAM, DMA]
Segment 11: len 0x00400 load 0x40070000 file_offs 0x00003cfc [CACHE_PRO]
Segment 12: len 0x00100 load 0x40070400 file_offs 0x00004104 [CACHE_PRO]
Segment 13: len 0x000c0 load 0x40070500 file_offs 0x0000420c [CACHE_PRO]
Segment 14: len 0x000a8 load 0x400705c0 file_offs 0x000042d4 [CACHE_PRO]
Segment 15: len 0x00010 load 0x40070668 file_offs 0x00004384 [CACHE_PRO]
Segment 16: len 0x00040 load 0x40070678 file_offs 0x0000439c [CACHE_PRO]
Segment 17: len 0x102c0 load 0x400706b8 file_offs 0x000043e4 [CACHE_PRO]
Checksum: 78 (valid)
Validation Hash: d4f10000a7b5699213e59502831fe3429920c7edd088e5e82025589f5a0a18b6 (valid)

If not, I get this:
$ esptool.py --chip esp32 elf2image ./zephyr.elf
esptool.py v2.9-dev

A fatal error occurred: Invalid segment count 17 (max 16). Usually this indicates a linker script problem.

[ESP_Angus]

If I modify the limit segments from 16 to 17, and do the same elf2image, I get this:

This is really odd that the result is different... the sections in the .bin don't even seem to exist in the .elf file you posted.

Are we definitely using the same ELF file? This is what I get running objdump & md5sum over the one that's attached:

Code: Select all

$ xtensa-esp32-elf-objdump -h zephyr.txt 

zephyr.txt:     file format elf32-xtensa-le

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .rtc.text     00000000  400c0000  400c0000  0000351c  2**0
                  CONTENTS
  1 .iram0.vectors 00000400  40080000  40080000  00000074  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 initlevel     0000006c  3ffb0000  3ffb0000  000031d0  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  3 _k_mutex_area 00000014  3ffb006c  3ffb006c  0000323c  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  4 sw_isr_table  00000100  40080400  40080400  00000474  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  5 devconfig     0000006c  40080500  40080500  00000574  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  6 text          00002be6  4008056c  4008056c  000005e0  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  7 .dram0.data   00000078  3ffb0080  3ffb0080  00003250  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  8 rodata        00000254  3ffb00f8  3ffb00f8  000032c8  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  9 bss           00000210  3ffb0350  3ffb0350  0000351c  2**3
                  ALLOC
 10 app_noinit    00000000  3ffb0560  3ffb0560  0000351c  2**0
                  CONTENTS
 11 noinit        00001400  3ffb0560  3ffb0560  0000351c  2**4
                  ALLOC
 12 .comment      0000003a  00000000  00000000  0000351c  2**0
                  CONTENTS, READONLY
 13 .debug_aranges 000010e8  00000000  00000000  00003558  2**3
                  CONTENTS, READONLY, DEBUGGING
 14 .debug_info   0002bb7a  00000000  00000000  00004640  2**0
                  CONTENTS, READONLY, DEBUGGING
 15 .debug_abbrev 00008ebe  00000000  00000000  000301ba  2**0
                  CONTENTS, READONLY, DEBUGGING
 16 .debug_line   0000f125  00000000  00000000  00039078  2**0
                  CONTENTS, READONLY, DEBUGGING
 17 .debug_frame  00002200  00000000  00000000  000481a0  2**2
                  CONTENTS, READONLY, DEBUGGING
 18 .debug_str    000051bf  00000000  00000000  0004a3a0  2**0
                  CONTENTS, READONLY, DEBUGGING
 19 .debug_loc    0000ec14  00000000  00000000  0004f55f  2**0
                  CONTENTS, READONLY, DEBUGGING
 20 .debug_ranges 00001cd0  00000000  00000000  0005e178  2**3
                  CONTENTS, READONLY, DEBUGGING
 21 .xtensa.info  00000038  00000000  00000000  0005fe48  2**0
                  CONTENTS, READONLY

$ md5sum zephyr.txt 
8a6f57f95e21927157a95fde1f256f77  zephyr.txt