NO_SWAP error from pages_init() when initializing FDS

RE: NO_SWAP error from pages_init() when initializing FDS

arthare — Thu, 03 Jan 2019 16:39:53 GMT

I fixed this with a similar approach as senorwigglez by wiping out the old data. I did it by modifying fds_init() to wipe out the data and let FDS re-init.

I added a parameter force_wipe so the caller can demand a clean start. If it encountered NO_PAGES or NO_SWAP, then I changed init_opts to FRESH_INSTALL, and let it continue and wipe out the storage rather than failing by returning FDS_ERR_NO_PAGES. Seems to work so far.

switch (init_opts)
    {
        case NO_PAGES:
        case NO_SWAP:
            if(eInitMode == FDS_INIT_FORCE_REDO)
            {
                // they want to force a fresh filesystem on us
                init_opts = FRESH_INSTALL;
            }
            else
            {
                return FDS_ERR_NO_PAGES;
            }

        case ALREADY_INSTALLED:
        {
            // No initialization is necessary. Notify the application immediately.
            m_flags.initialized  = true;
            m_flags.initializing = false;
            event_send(&evt_success);
            return FDS_SUCCESS;
        }

        default:
            break;
    }

RE: NO_SWAP error from pages_init() when initializing FDS

senorwigglez — Wed, 30 May 2018 13:14:27 GMT

Alright so I managed to get something working. It's not a clean solution by any means but it seems to get the job done. For anyone else that happens to have this problem this is what I did:

1. Set a flag in the main loop when you want to do a DFU (in my case I had a custom BLE service that I could just write to and set the flag)

2. Call a function to erase the flash pages used by using sd_flash_page_erase

2a. I wasn't able to get NRF_EVT_FLASH_OPERATION_SUCCESS events reliably at all so instead of checking for it, I just implemeneted the following loop:

  ret_code_t err_code;
  uint32_t event_type;

  for (int i = 0; i < FDS_VIRTUAL_PAGES; i++)
  {
    // address will look like 0x6A000 and we just want 0x6A so shift the
    // lower bits out
    err_code = sd_flash_page_erase((m_fs.start_addr >> 12) + i);

    // if sd is busy then wait for another sd event before trying again
    while(err_code == NRF_ERROR_BUSY)
    {
      sd_app_evt_wait();
      err_code = sd_flash_page_erase((m_fs.start_addr >> 12) + i);
    }

    // fetch events in queue until there are none left which should include
    // the flash event
    while(sd_evt_get(&event_type) == NRF_SUCCESS);
  }

Now the pages used for FDS should be erased and you can run DFU and the device will initialize normally. I have no idea whether this is a safe way to implement this but again I don't see any erase way to do it through the FDS API.

RE: NO_SWAP error from pages_init() when initializing FDS

senorwigglez — Tue, 29 May 2018 09:16:59 GMT

Hi Edvin,

pages_init returns 0x02. If I set a breakpoint in the loop when all of the pages are initialized, all them are "FDS_PAGE_DATA" and I believe aren't able to be garbage collected which is why the initialization fails.

All four pages (from 0x74000 - 0x77000) show: 0xDEADC0DE 0xF11E01FE

This makes sense if we're getting FDS_PAGE_DATA during the page intialization.

What I want to implement is some way to just deallocate or completely erase the area used by FDS in between DFU updates. I can't seem to find a straightforward way to do this using only FDS however.

RE: NO_SWAP error from pages_init() when initializing FDS

Edvin — Tue, 29 May 2018 07:36:23 GMT

Can you also check the first and second word on the pages that you try to initialize, before you run pages_init()?

See here to see the descriptions. is word0 0xDEADC0DE and word1 either 0xF11E0FF or 0xF11E0FE?

BR,

Edvin

RE: NO_SWAP error from pages_init() when initializing FDS

Edvin — Tue, 29 May 2018 07:32:34 GMT

Hello,

I am sorry for the late reply.

Can you confirm whether your pages_init() function actually returns NO_SWAP, or if it returns NO_PAGES (since there is no break; between these cases in the switch after pages_init();

Can you check which one(s) of the returns that are added in static fds_init_opts_t pages_init(void) in fds.c, starting from line 632 (if not modified)?

The reason I ask is that the return FDS_ERR_NO_PAGES means that pages_init() returns 0x00 or 0x02.

This means that either, the return stays the same as it is initialized in pages_init: ret = NO_PAGES, or it is ret |= PAGE_DATA.

Can you check what lines that ret is changed inside pages_init()?

Best regards,

Edvin