Hi all, this might be worth mentioning: https://github.com/apache/mynewt-core/pull/1557 <https://github.com/apache/mynewt-core/pull/1557>.
flash_loader app runs on MCU, and expects commands to be written directly to RAM. Commands like ‘write data to flash’, ‘erase’, ‘write-and-verify’ and ‘read’. So now there’s now tooling to populate external flash for platforms which either a) have external SPI flash in addition to internal flash, and you need to get data there. Or b) MCUs which execute from RAM, and have only external SPI flash to store it’s images. If your JTAG programmer can do this automatically, great. If not, you could use this to do the programming. flash_loader, like other mynewt apps, is built using a specific BSP. And it will be able to do this operations on any flash which appears in the BSP flash device table. You could think of it as hal_flash interface which is exported to JTAG programmer. I assume people will always execute this from RAM, and an example on how this could work using nordic_pca10040 BSP. See https://github.com/apache/mynewt-core/pull/1547 <https://github.com/apache/mynewt-core/pull/1547>. Of course, you’ll want to have scripting on the programmer side to feed data in/out of the flash_loader app. I implemented this using gdb scripts (as that’s the debugger of choice for us, and can run over openocd and Segger JLink). These helper routines are located here: https://github.com/apache/mynewt-core/blob/master/compiler/gdbmacros/flash_loader.gdb <https://github.com/apache/mynewt-core/blob/master/compiler/gdbmacros/flash_loader.gdb> You can, of course, replace these with openocd/JLink scripts. Contributions always welcome. Here’s a gdb script I use to populate the image slot1 with these scripts for nordic_pca10040: —8<—cut-start— set pagination off shell sh -c "trap '' 2; JLinkGDBServer -device nRF52 -speed 4000 -if SWD -port 3333 -singlerun > logfile.txt 2>&1 &" target remote localhost:3333 mon reset restore bin/targets/fl_nrf52dk/app/apps/flash_loader/flash_loader.elf.bin binary 0x20000000 symbol-file bin/targets/fl_nrf52dk/app/apps/flash_loader/flash_loader.elf set $sp=*(int *)0x20000000 set $pc=*(int *)0x20000004 b blink_led c source repos/apache-mynewt-core/compiler/gdbmacros/flash_loader.gdb mon go fl_load nrf52.img 0 0x42000 mon halt mon reset quit —8<—cut-end--- And here’s my flash loader app target for that BSP. targets/fl_nrf52dk app=@apache-mynewt-core/apps/flash_loader bsp=@apache-mynewt-core/hw/bsp/nordic_pca10040 build_profile=optimized syscfg=FLASH_LOADER_DL_SZ=0x8000:RAM_RESIDENT=1
