RE: Custom SPI Bootloader (from Flash)

Sigurd — Wed, 13 Sep 2017 12:47:03 GMT

Hi,

The next step would be to be able to debug the bootloader. When compiling with optimization level to 0, you will need to allocate more flash space for the bootloader in the .ld file.

You will also need to add -fomit-frame-pointer to the compiler flags for it to compile correctly.

RE: Custom SPI Bootloader (from Flash)

Vehring — Wed, 06 Sep 2017 09:25:19 GMT

I get the feeling (no, i still can't compile a debug compatible firmware), that the problem is related to the spi. I can initialize an spi interface but working with it is not possible. May it be related to the Easy DMA?

A typical read from flash looks like this (m_spi_xfer_done is set by the dma callback when transfer was executed):

if (pin_cs > 0){Flash_AT25_select();}
flash_spi->m_spi_xfer_done = false;
err_code = nrf_drv_spi_transfer(&flash_spi->m_spi_instance,&m_tx_buf,4,&m_rx_buf,length_bytes+4);
while (!flash_spi->m_spi_xfer_done)
{
	//Prevent Low Power State
	__WFE();
}
if (pin_cs > 0){Flash_AT25_unselect();}

So, first question: I read now about the interrupt forwarding of the mbr. how does it work? Do i need the forwarding here? I have a softdevice flashed (S132 V4.0.2), but want to leave it disabled if possible in the bootloader.