-
Notifications
You must be signed in to change notification settings - Fork 13.3k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Support to reboot into UART download mode
without any external wiring.
This patch introduces the new method
Esp.rebootIntoUartDownloadMode()
When the user calls this method the ESP8266 reboots into the UART
download mode. In this mode the user can use esptool.py to flash a new
firmware file. The following command was used to test it:
$ esptool.py --before no_reset --after soft_reset --chip esp8266 \
--port /dev/ttyUSB0 --baud 460800 write_flash 0x0 firmware.bin
The implementation is based on the original implementation in the
boot ROM. Some parts of the original implementation can be found in
[1]. This patch is a squashed and simplified version of [2]. The non
squashed version might be helpful in case of debugging issues.
[1] https://github.com/twischer/xtensa-subjects/blob/master/reversed/bootrom.c
[2] https://github.com/twischer/Arduino/tree/reboot_uart_download_full
Signed-off-by: Timo Wischer <[email protected]>- Loading branch information
Showing
14 changed files
with
246 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,151 @@ | ||
| /* | ||
| ESP8266-specific implementation of the UART download mode | ||
| Copyright (c) 2021 Timo Wischer <[email protected]> | ||
| All rights reserved. | ||
| This file is part of the esp8266 core for Arduino environment. | ||
| This library is free software; you can redistribute it and/or | ||
| modify it under the terms of the GNU Lesser General Public | ||
| License as published by the Free Software Foundation; either | ||
| version 2.1 of the License, or (at your option) any later version. | ||
| This library is distributed in the hope that it will be useful, | ||
| but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| Lesser General Public License for more details. | ||
| You should have received a copy of the GNU Lesser General Public | ||
| License along with this library; if not, write to the Free Software | ||
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | ||
| This implementation is based on the original implementation of the ROM. | ||
| It was shortend to reduce the memory usage. The complete version and the | ||
| development history can be found in: | ||
| https://github.com/twischer/Arduino/tree/reboot_uart_download_full | ||
| This might be usefull in case of issues. | ||
| */ | ||
| #include "reboot_uart_dwnld.h" | ||
| #include <stdnoreturn.h> | ||
| #include <user_interface.h> | ||
| #include <esp8266_undocumented.h> | ||
|
|
||
|
|
||
| static inline uint32_t __rsil_1() { | ||
| uint32_t program_state; | ||
| asm volatile("rsil %0, 1" : "=r" (program_state)); | ||
| return program_state; | ||
| } | ||
|
|
||
| static inline void __wsr_intenable(uint32_t interupt_enable) { | ||
| asm volatile("wsr.intenable %0" :: "r" (interupt_enable)); | ||
| } | ||
|
|
||
| static inline void __wsr_litbase(uint32_t literal_base) { | ||
| asm volatile("wsr.litbase %0" :: "r" (literal_base)); | ||
| } | ||
|
|
||
| static inline void __wsr_ps(uint32_t program_state) { | ||
| asm volatile("wsr.ps %0" :: "r" (program_state)); | ||
| } | ||
|
|
||
| static inline void __wsr_vecbase(uint32_t vector_base) { | ||
| asm volatile("wsr.vecbase %0" :: "r" (vector_base)); | ||
| } | ||
|
|
||
| [[noreturn]] void ICACHE_RAM_ATTR esp8266UartDownloadMode() | ||
| { | ||
| /* reverse engineered from system_restart_core() */ | ||
| /* Before disabling instruction cache and restoring instruction RAM to a | ||
| * power-on like state, SPI bus must be idle. | ||
| */ | ||
| Wait_SPI_Idle(flashchip); | ||
|
|
||
| Cache_Read_Disable(); | ||
| /* This will disable the 32kB instruction cache and extend the IRAM by 32kB. | ||
| * Therefore the full 64kB of IRAM will be available for boot. | ||
| * Cache_Read_Enable() sets those bits but Cache_Read_Disable() does not clear | ||
| * them. On hardware reset those bits are cleared. Therefore clear them also | ||
| * for this reboot. | ||
| */ | ||
| CLEAR_PERI_REG_MASK(PERIPHS_DPORT_ICACHE_ENABLE, | ||
| ICACHE_ENABLE_FIRST_16K | ICACHE_ENABLE_SECOND_16K); | ||
|
|
||
| /* reverse engineered from _ResetHandler() */ | ||
| /* disable all level 1 interrupts */ | ||
| __wsr_intenable(0); | ||
| /* Clear the literal base to use an offset of 0 for | ||
| * Load 32-bit PC-Relative(L32R) instructions | ||
| */ | ||
| __wsr_litbase(0); | ||
| asm volatile("rsync"); | ||
|
|
||
| /* Set interrupt vector base address to system ROM */ | ||
| __wsr_vecbase(0x40000000); | ||
| /* Set interrupt level to 1. Therefore disable interrupts of level 1. | ||
| * Above levels like level 2,... might still be active if available | ||
| * on ESP8266. | ||
| */ | ||
| __rsil_1(); | ||
|
|
||
| /* reverse engineered from _start() */ | ||
| /* Set stack pointer to upper end of data RAM */ | ||
| const uint32_t stack_pointer = 0x40000000; | ||
| asm volatile("mov a1, %0" :: "r" (stack_pointer)); | ||
|
|
||
| /* Set the program state register | ||
| * Name Value Description | ||
| * Interrupt level disable 0 enable all interrupt levels | ||
| * Exception mode 0 normal operation | ||
| * User vector mode 1 user vector mode, exceptions need to switch stacks | ||
| * Privilege level 0 Set to Ring 0 | ||
| */ | ||
| __wsr_ps(0x20); | ||
| asm volatile("rsync"); | ||
|
|
||
| /* reverse engineered from main() */ | ||
| const uint32_t uart_no = 0; | ||
| uartAttach(); | ||
| Uart_Init(uart_no); | ||
| ets_install_uart_printf(uart_no); | ||
|
|
||
| /* reverse engineered from boot_from_something() */ | ||
| const uint16_t divlatch = uart_baudrate_detect(uart_no, 0); | ||
| rom_uart_div_modify(uart_no, divlatch); | ||
| UartDwnLdProc((uint8_t*)0x3fffa000, 0x2000, &user_start_fptr); | ||
|
|
||
| /* reverse engineered from main() */ | ||
| if (user_start_fptr == NULL) { | ||
| if (boot_from_flash() != 0) { | ||
| ets_printf("boot_from_flash() failed\n"); | ||
| while (true); | ||
| } | ||
| } | ||
|
|
||
| if (user_start_fptr) { | ||
| user_start_fptr(); | ||
| } | ||
|
|
||
| ets_printf("user code done\n"); | ||
| ets_run(); | ||
| } | ||
|
|
||
| [[noreturn]] void esp8266RebootIntoUartDownloadMode() | ||
| { | ||
| /* reverse engineered from system_restart_local() */ | ||
| if (system_func1(0x4) == -1) { | ||
| clockgate_watchdog(0); | ||
| SET_PERI_REG_MASK(PERIPHS_DPORT_18, 0xffff00ff); | ||
| pm_open_rf(); | ||
| } | ||
|
|
||
| user_uart_wait_tx_fifo_empty(0, 0x7a120); | ||
| user_uart_wait_tx_fifo_empty(1, 0x7a120); | ||
| ets_intr_lock(); | ||
| SET_PERI_REG_MASK(PERIPHS_DPORT_18, 0x7500); | ||
| CLEAR_PERI_REG_MASK(PERIPHS_DPORT_18, 0x7500); | ||
| SET_PERI_REG_MASK(PERIPHS_I2C_48, 0x2); | ||
| CLEAR_PERI_REG_MASK(PERIPHS_I2C_48, 0x2); | ||
|
|
||
| esp8266UartDownloadMode(); | ||
| } | ||
|
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,23 @@ | ||
| /* | ||
| ESP8266-specific implementation of the UART download mode | ||
| Copyright (c) 2021 Timo Wischer <[email protected]> | ||
| All rights reserved. | ||
| This file is part of the esp8266 core for Arduino environment. | ||
| This library is free software; you can redistribute it and/or | ||
| modify it under the terms of the GNU Lesser General Public | ||
| License as published by the Free Software Foundation; either | ||
| version 2.1 of the License, or (at your option) any later version. | ||
| This library is distributed in the hope that it will be useful, | ||
| but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| Lesser General Public License for more details. | ||
| You should have received a copy of the GNU Lesser General Public | ||
| License along with this library; if not, write to the Free Software | ||
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | ||
| */ | ||
| #include <stdnoreturn.h> | ||
|
|
||
| [[noreturn]] void esp8266RebootIntoUartDownloadMode(); |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Binary file not shown.
Binary file not shown.
Binary file not shown.
Binary file not shown.
Binary file not shown.
Binary file not shown.
Binary file not shown.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters