Development environment：
NRF52832
SDK：15.3
SOFTDEVICE：NONE
When testing the FDS module power-off data protection feature, the FDS module is abnormal.
During the FDS module garbage collection process, performing a software reset may cause the FLASH data to be abnormal.
I checked the source code of the FDS and found that the following problems might exist:
Stage 1: FDS garbage collection execution, copy data_page to swap_page
Stage 2: Erase data_page
Stage 3: Perform a software reset
Stage 4: First find the erase_page in the execution of the functions pages_init(), and then tag the erase_page as swap_page. This will cause m_gc.cur_page not to be set.
case FDS_PAGE_UNDEFINED:
{
if (page_is_erased(p_page_addr))
{
if (m_swap_page.p_addr != NULL)
{
// If a swap page is already set, flag the page as erased (in m_pages)
// and try to tag it as data (in flash) later on during initialization.
m_pages[page].page_type = FDS_PAGE_ERASED;
m_pages[page].p_addr = p_page_addr;
m_pages[page].write_offset = FDS_PAGE_TAG_SIZE;
// This is a candidate for a potential new swap page, in case the
// current swap is going to be promoted to complete a GC instance.
m_gc.cur_page = page;
page++;
}
else
{
/*********************************************/
// m_gc.cur_page not to be set
/********************************************/
// If there is no swap page yet, use this one.
m_swap_page.p_addr = p_page_addr;
m_swap_page.write_offset = FDS_PAGE_TAG_SIZE;
swap_set_but_not_found = true;
}
ret |= PAGE_ERASED;
}
else
{
// The page contains non-FDS data.
// Do not initialize or use this page.
total_pages_available--;
m_pages[page].p_addr = p_page_addr;
m_pages[page].page_type = FDS_PAGE_UNDEFINED;
page++;
}
} break;Stage 5: After page_init() is executed, init_opts = 0x0B, and then the following code is executed:
case FDS_OP_INIT_PROMOTE_SWAP:
{
p_op->init.step = FDS_OP_INIT_TAG_SWAP;
// When promoting the swap, keep the write_offset set by pages_init().
ret = page_tag_write_data(m_swap_page.p_addr);
/******************************************************/
//m_gc.cur_page has not been set
/******************************************************/
uint16_t const gc = m_gc.cur_page;
uint32_t const * const p_old_swap = m_swap_page.p_addr;
// Execute the swap.
m_swap_page.p_addr = m_pages[gc].p_addr;
m_pages[gc].p_addr = p_old_swap;
// Copy the offset from the swap to the new page.
m_pages[gc].write_offset = m_swap_page.write_offset;
m_swap_page.write_offset = FDS_PAGE_TAG_SIZE;
m_pages[gc].page_type = FDS_PAGE_DATA;
} break;
Stage 6:FDS module data is abnormal, SWAP_PAGE will not be found
Please confirm this question, thank you!
