CircuitPython - a Python implementation for teaching coding with microcontrollers https://git.suspectdevices.com/suspect-devices/circuitpython/atom?h=6.0.0 2020-09-28T23:55:56+00:00 2020-09-28T23:55:56+00:00 Jeff Epler jepler@gmail.com 2020-09-24T16:20:32+00:00 urn:sha1:726dcdb60aa84b5070e5484a19e896abdaffeb93 I have a function where it should be impossible to reach the end, so I put in a safe-mode reset at the bottom: ``` int find_unused_slot(void) { // precondition: you already verified that a slot was available for (int i=0; i<NUM_SLOTS; i++) { if( slot_free(i)) { return i; } } safe_mode_reset(MICROPY_FATAL_ERROR); } ``` However, the compiler still gave a diagnostic, because safe_mode_reset was not declared NORETURN. So I started by teaching the compiler that reset_into_safe_mode never returned. This leads at least one level deeper due to reset_cpu needing to be a NORETURN function. Each port is a little different in this area. I also marked reset_to_bootloader as NORETURN. Additional notes: * stm32's reset_to_bootloader was not implemented, but now does a bare reset. Most stm32s are not fitted with uf2 bootloaders anyway. * ditto cxd56 * esp32s2 did not implement reset_cpu at all. I used esp_restart(). (not tested) * litex did not implement reset_cpu at all. I used reboot_ctrl_write. But notably this is what reset_to_bootloader already did, so one or the other must be incorrect (not tested). reboot_ctrl_write cannot be declared NORETURN, as it returns unless the special value 0xac is written), so a new unreachable forever-loop is added. * cxd56's reset is via a boardctl() call which can't generically be declared NORETURN, so a new unreacahble "for(;;)" forever-loop is added. * In several places, NVIC_SystemReset is redeclared with NORETURN applied. This is accepted just fine by gcc. I chose this as preferable to editing the multiple copies of CMSIS headers where it is normally declared. * the stub safe_mode reset simply aborts. This is used in mpy-cross. 2020-09-24T21:57:20+00:00 Jeff Epler jepler@gmail.com 2020-09-24T21:57:10+00:00 urn:sha1:6bcbe51f7fcfaca6ee3ee40b4ce64fd791725e8f 2020-07-06T18:16:25+00:00 Diego Elio Pettenò flameeyes@flameeyes.com 2020-06-03T22:40:05+00:00 urn:sha1:34b4993d63a6b576f29d624385c681f679b4124c 2020-06-03T09:56:35+00:00 Diego Elio Pettenò flameeyes@flameeyes.com 2020-05-30T09:44:13+00:00 urn:sha1:dd5d7c86d22807c021dd1711eb7dd3daebc5cfcf This can be enforced by pre-commit, but correct it separately to make it easier to review. 2020-05-19T00:02:52+00:00 Mark Olsson post@markolsson.se 2020-05-18T12:04:55+00:00 urn:sha1:007c92ee6ab8da342dacb8967ef999b6d83596ec 2019-09-06T15:06:02+00:00 Hierophect hierophect@gmail.com 2019-09-06T15:06:02+00:00 urn:sha1:bc376498845a67a0348f2f7c4a73fbb55b7563bb 2019-08-15T21:56:15+00:00 Hierophect hierophect@gmail.com 2019-08-15T21:56:15+00:00 urn:sha1:7dbf1a8caaebf15a634930b1b3e7f3bdc559a180 2019-08-15T19:55:33+00:00 Hierophect hierophect@gmail.com 2019-08-15T19:55:33+00:00 urn:sha1:a9d3ad86e5f400b9315fde58c9b8666a048956ca 2019-03-12T18:18:30+00:00 Scott Shawcroft scott@tannewt.org 2019-03-09T00:20:38+00:00 urn:sha1:d6b2199f3614a5fe2d4da4163ca901ac1e567f5f 2019-02-21T21:23:28+00:00 Scott Shawcroft scott@tannewt.org 2019-02-21T21:23:28+00:00 urn:sha1:ed1ace09e971b24bc9ff88defe2e128064780824