Fixing low-voltage flashing on STM32F7 parts.

[zulusw]

Added stm32f7.s and stm32f7lv.s (the sooner was already supported but probably the definition of loader_code_stm32f7 in flash_loader.c was just winged from the F4 version by manually adding the opcode for the "dsb").

Instead of copy & paste the voltage detection code, I refactored it into a function. If that is not cool, let me know and I can revert that part.

Also, I haven't got a chance to test it out on an M4 yet. Will do over the weekend.

[xor-gate]

Looks good, If you verify and let me know it works on M4 we are good to go!

[xor-gate]

Checked already on m4 ?

[zulusw]

Jerry, Here it is. (Tested both regular voltage and low voltage) Below is the low voltage log. Regards, Andrea. ``` 2017-03-14T10:48:11 INFO stlink/src/common.c: Loading device parameters.... 2017-03-14T10:48:11 INFO stlink/src/common.c: Device connected is: F42x and F43x device, id 0x20016419 2017-03-14T10:48:11 INFO stlink/src/common.c: SRAM size: 0x40000 bytes (256 KiB), Flash: 0x200000 bytes (2048 KiB) in pages of 16384 bytes 2017-03-14T10:48:11 INFO stlink/src/gdbserver/gdb-server.c: Chip ID is 00000419, Core ID is 2ba01477. 2017-03-14T10:48:11 INFO stlink/src/gdbserver/gdb-server.c: Listening at *:4242... 2017-03-14T10:48:19 INFO stlink/src/gdbserver/gdb-server.c: Found 6 hw breakpoint registers 2017-03-14T10:48:19 INFO stlink/src/gdbserver/gdb-server.c: GDB connected. 2017-03-14T10:48:23 INFO stlink/src/common.c: Attempting to write 16384 (0x4000) bytes to stm32 address: 134217728 (0x8000000) Flash page at addr: 0x08000000 erased 2017-03-14T10:48:24 INFO stlink/src/common.c: Finished erasing 1 pages of 16384 (0x4000) bytes 2017-03-14T10:48:24 INFO stlink/src/common.c: Starting Flash write for F2/F4/L4 2017-03-14T10:48:24 INFO stlink/src/flash_loader.c: Successfully loaded flash loader in sram Target voltage (2600 mV) too low for 32-bit flash, using 8-bit flash writes size: 16384 2017-03-14T10:48:24 INFO stlink/src/common.c: Starting verification of write complete 2017-03-14T10:48:25 INFO stlink/src/common.c: Flash written and verified! jolly good! 2017-03-14T10:48:25 INFO stlink/src/common.c: Attempting to write 16384 (0x4000) bytes to stm32 address: 134234112 (0x8004000) Flash page at addr: 0x08004000 erased 2017-03-14T10:48:25 INFO stlink/src/common.c: Finished erasing 1 pages of 16384 (0x4000) bytes 2017-03-14T10:48:25 INFO stlink/src/common.c: Starting Flash write for F2/F4/L4 2017-03-14T10:48:25 INFO stlink/src/flash_loader.c: Successfully loaded flash loader in sram Target voltage (2600 mV) too low for 32-bit flash, using 8-bit flash writes size: 16384 2017-03-14T10:48:26 INFO stlink/src/common.c: Starting verification of write complete 2017-03-14T10:48:26 INFO stlink/src/common.c: Flash written and verified! jolly good! 2017-03-14T10:48:26 INFO stlink/src/common.c: Attempting to write 16384 (0x4000) bytes to stm32 address: 134250496 (0x8008000) Flash page at addr: 0x08008000 erased 2017-03-14T10:48:26 INFO stlink/src/common.c: Finished erasing 1 pages of 16384 (0x4000) bytes 2017-03-14T10:48:26 INFO stlink/src/common.c: Starting Flash write for F2/F4/L4 2017-03-14T10:48:26 INFO stlink/src/flash_loader.c: Successfully loaded flash loader in sram Target voltage (2600 mV) too low for 32-bit flash, using 8-bit flash writes size: 16384 2017-03-14T10:48:27 INFO stlink/src/common.c: Starting verification of write complete 2017-03-14T10:48:27 INFO stlink/src/common.c: Flash written and verified! jolly good! ```

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On Tue, Mar 14, 2017 at 7:18 AM, Jerry Jacobs ***@***.***> wrote: Checked already on m4 ? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#567 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ASyAWVA4JEHM3rKa4RaAYP2-bfMN9Hopks5rlqHHgaJpZM4MZ7Tu> .

[xor-gate]

Great, thanks for the improvement!