+
+## Uploading the Flash Loader
+
+- Compile using specific toolchains
+- Extract text and data sections from resulting ELF file
+- Generate header file that is compiled with the extraction tool
+- This includes section's sizes, addresses and the entry point
+- Upload the corresponding loader after identifying the chip
+
+::: notes
+- toolchains are downloaded automatically from the Makefile
+- proprietary forks of gcc and clang, only available as binary downloads
+:::
+
+##
+```c
+const unsigned char *elf_esp32_text_buffer =
+ (unsigned char[]){0x08,0x00,0xf4,...};
+const unsigned long elf_esp32_text_size = 2100;
+const unsigned long elf_esp32_text_addr = 1074520064;
+
+const unsigned char *elf_esp32_data_buffer =
+ (unsigned char[]){0x9b,0xe6,0x0b,...};
+const unsigned long elf_esp32_data_size = 60;
+const unsigned long elf_esp32_data_addr = 1073561756;
+
+const unsigned long elf_esp32_entry = 1074521000;
+```
+
+
+
+<!-- differences between esp versions -->
+<!-- - identification: -->
+<!-- - ESP32-C3 and later use GET_SECURITY_INFO which contains a chip_id -->
+<!-- - previous models have a register with a magic value identifying the chip -->
+<!-- - mac address: -->
+<!-- - different registers -->
+<!-- - esp8266 mac has to be calculated -->
+<!-- - different flash loader versions -->
+<!-- - esp8266 has no data section -->
+
+## Different ESP Versions
+
+- ESP32-C3 and later are identified using `GET_SECURITY_INFO` command
+- Earlier versions have a register with a magic value
+- Try security info first and reset on failure
+- Different registers containing MAC address
+
+::: notes
+- sec info first bc it fails with unknown command
+- read register is a known command
+- reset -> bootmode -> sync again
+- on ESP8266 mac has to be calculated
+- esp8266 has no data section when compiling flash loader
+:::
+
+
+
projects / ouroboros-slides / blobdiff