Low-level ESP32 bootloader SLIP communication protocol #887
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gemenerik
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Supports intuitive assembling/interpretation without buffer fiddling.
Buffer to send will be sent to ESP32 over UART2.
*coms_sendbuffer_t Function takes buffer to write to ESP32 over UART. *coms_getDataWithTimeout_t *c is a pointer to to be written char timeoutTicks is the number of ticks before returning timeout (false) Allows for mocking UART comms in test environment.
Includes escape sequence for 0xC0 and 0xDB in data. Fed data size excludes escape sequence bytes.
This function allows clearing the buffer before sending a new package. The ESP32 sends no unsollicited SLIP packages (READ_FLASH is exception). ESP32 sends confirmation package several times upon synchronization. This can overflow incoming buffer. Clearing buffer avoids putting packet receiving FSM in the wrong state.
Builds receiving packet struct using SLIP decoding state machine.
1. Clears incoming buffer 2. Assembles buffer to send 3. Sends buffer 4. Receives response from ESP32
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Code is generic and should contain no reference to underlying communication.
Allows for static sendBuffer. Can be compared to actual transmission buffer size on a higher level. Designed such that buffer can be sent over UART2 DMA which has a limited buffer size.
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In general really really nice and clean code! Well done @gemenerik !
Static variables are 0 by default
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Low-level implementation of ESP32 ROM bootloader communication protocol. First stepping stone to wireless flashing of ESP32 from zip.
The ESP32 bootloader sends no unsolicited messages. The exchange function can be called from a higher level with a variation of instructions and data (to write). The exchange executes the following tasks: