a08995b302
When a symbol needs to be placed to a different target than the one
designated for the object file, the object file is expanded, which
includes the following steps:
1. Creating a new placement for the symbol's input section with the
specified target.
2. Excluding the object placement from the orignal target.
3. Creating a new intermediate placement for the object for the original
target, where its input sections are expanded, excluding the input
section for the symbol.
Let's illustrate the object expansion process with the following example:
[sections:rodata]
entries:
.rodata+
.sdata2+
.srodata+
[scheme:default]
entries:
text -> flash_text
rodata -> flash_rodata
[scheme:noflash]
entries:
text -> iram0_text
rodata -> dram0_data
[mapping:soc_pm]
archive: libsoc.a
entries:
gpio_periph: GPIO_HOLD_MASK (noflash)
gpio_periph section headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .text PROGBITS 00000000 000034 000000 00 AX 0 0 2
[ 2] .data PROGBITS 00000000 000034 000000 00 WA 0 0 1
[ 3] .bss NOBITS 00000000 000034 000000 00 WA 0 0 1
[ 4] .rodata.GPIO_HOLD_MASK PROGBITS 00000000 000034 000058 00 A 0 0 4
[ 5] .rodata.GPIO_PIN_MUX_REG PROGBITS 00000000 00008c 000058 00 A 0 0 4
[ 6] .debug_info PROGBITS 00000000 0000e4 0000d8 00 0 0 1
[ 7] .rela.debug_info RELA 00000000 0009d4 000108 0c I 16 6 4
[ 8] .debug_abbrev PROGBITS 00000000 0001bc 000070 00 0 0 1
[ 9] .debug_aranges PROGBITS 00000000 00022c 000018 00 0 0 1
[10] .rela.debug_aranges RELA 00000000 000adc 00000c 0c I 16 9 4
[11] .debug_line PROGBITS 00000000 000244 0001ab 00 0 0 1
[12] .debug_str PROGBITS 00000000 0003ef 00022d 01 MS 0 0 1
[13] .comment PROGBITS 00000000 00061c 000030 01 MS 0 0 1
[14] .note.GNU-stack PROGBITS 00000000 00064c 000000 00 0 0 1
[15] .riscv.attributes RISCV_ATTRIBUTES 00000000 00064c 000044 00 0 0 1
[16] .symtab SYMTAB 00000000 000690 000260 10 17 36 4
[17] .strtab STRTAB 00000000 0008f0 0000e1 00 0 0 1
[18] .shstrtab STRTAB 00000000 000ae8 0000d1 00 0 0 1
1. Creating a new placement
.dram0.data :
{
*libsoc.a:gpio_periph.*(.rodata.GPIO_HOLD_MASK .sdata2.GPIO_HOLD_MASK .srodata.GPIO_HOLD_MASK)
}
2. Excluding the object placement
.flash.rodata :
{
*(EXCLUDE_FILE(*libsoc.a:gpio_periph.*) .rodata.* ...)
}
3. Creating a new intermediate placement
.flash.rodata :
{
*libsoc.a:gpio_periph.*(.rodata.GPIO_PIN_MUX_REG)
}
Now, let's do the same, but also move GPIO_PIN_MUX_REG to noflash with an updated mapping.
[mapping:soc_pm]
archive: libsoc.a
entries:
gpio_periph: GPIO_HOLD_MASK (noflash)
gpio_periph: GPIO_PIN_MUX_REG (noflash)
1. Creating a new placement
.dram0.data :
{
*libsoc.a:gpio_periph.*(.rodata.GPIO_HOLD_MASK .sdata2.GPIO_HOLD_MASK .srodata.GPIO_HOLD_MASK)
*libsoc.a:gpio_periph.*(.rodata.GPIO_PIN_MUX_REG .sdata2.GPIO_PIN_MUX_REG
.srodata.GPIO_PIN_MUX_REG)
}
2. Excluding the object placement
.flash.rodata :
{
*(EXCLUDE_FILE(*libsoc.a:gpio_periph.*) .rodata.* ...)
}
3. Creating a new intermediate placement
.flash.rodata :
{
*libsoc.a:gpio_periph.*
}
The *libsoc.a:gpio_periph.* entity in step 3 no longer has input
sections, as there are no remaining .rodata input sections in the object
file. The linker behavior for this mapping is to include all object
input sections that have not yet been placed as described in
https://sourceware.org/binutils/docs/ld.html#Input-Section-Basics
"If you use a file name without a list of sections, then all sections in
the input file will be included in the output section. This is not
commonly done, but it may by useful on occasion."
The map file for such mapping now contains following input sections
.flash.rodata 0x3c0a0120 0x19b34
*libsoc.a:gpio_periph.*()
.debug_info 0x3c0b95bf 0xd8 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.debug_abbrev 0x3c0b9697 0x70 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.debug_aranges
0x3c0b9707 0x18 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.debug_line 0x3c0b971f 0x1ab esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.debug_str 0x3c0b98ca 0x21a esp-idf/soc/libsoc.a(gpio_periph.c.obj)
0x22d (size before relaxing)
.comment 0x3c0b9ae4 0x30 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.note.GNU-stack
0x3c0b9ae4 0x0 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
.riscv.attributes
0x3c0b9ae4 0x44 esp-idf/soc/libsoc.a(gpio_periph.c.obj)
This is incorrect, and such intermediate placement should not be
generated. This type of placement can be recognized because it is not
explicitly defined in the mapping and lacks input sections. We can
identify this in the significant function and prevent issuing commands
for such placement.
Signed-off-by: Frantisek Hrbata <frantisek.hrbata@espressif.com>
Espressif IoT Development Framework
ESP-IDF is the development framework for Espressif SoCs supported on Windows, Linux and macOS.
ESP-IDF Release Support Schedule
- Please read the support policy and the documentation for more information about ESP-IDF versions.
- Please see the End-of-Life Advisories for information about ESP-IDF releases with discontinued support.
ESP-IDF Release and SoC Compatibility
The following table shows ESP-IDF support of Espressif SoCs where 
| Chip | v5.0 | v5.1 | v5.2 | v5.3 | v5.4 | |
|---|---|---|---|---|---|---|
| ESP32 | |
|
|
|
|
|
| ESP32-S2 | |
|
|
|
|
|
| ESP32-C3 | |
|
|
|
|
|
| ESP32-S3 | |
|
|
|
|
Announcement |
| ESP32-C2 | |
|
|
|
|
Announcement |
| ESP32-C6 | |
|
|
|
Announcement | |
| ESP32-H2 | |
|
|
|
Announcement | |
| ESP32-P4 | |
|
Announcement | |||
| ESP32-C5 | |
Announcement | ||||
| ESP32-C61 | |
Announcement |
There are variants of revisions for a series of chips. See Compatibility Between ESP-IDF Releases and Revisions of Espressif SoCs for the details of the compatibility between ESP-IDF and chip revisions.
Espressif SoCs released before 2016 (ESP8266 and ESP8285) are supported by RTOS SDK instead.
Developing With ESP-IDF
Setting Up ESP-IDF
See https://idf.espressif.com/ for links to detailed instructions on how to set up the ESP-IDF depending on chip you use.
Note: Each SoC series and each ESP-IDF release has its own documentation. Please see Section Versions on how to find documentation and how to checkout specific release of ESP-IDF.
Non-GitHub forks
ESP-IDF uses relative locations as its submodules URLs (.gitmodules). So they link to GitHub. If ESP-IDF is forked to a Git repository which is not on GitHub, you will need to run the script tools/set-submodules-to-github.sh after git clone.
The script sets absolute URLs for all submodules, allowing git submodule update --init --recursive to complete. If cloning ESP-IDF from GitHub, this step is not needed.
Finding a Project
As well as the esp-idf-template project mentioned in Getting Started, ESP-IDF comes with some example projects in the examples directory.
Once you've found the project you want to work with, change to its directory and you can configure and build it.
To start your own project based on an example, copy the example project directory outside of the ESP-IDF directory.
Quick Reference
See the Getting Started guide links above for a detailed setup guide. This is a quick reference for common commands when working with ESP-IDF projects:
Setup Build Environment
(See the Getting Started guide listed above for a full list of required steps with more details.)
- Install host build dependencies mentioned in the Getting Started guide.
- Run the install script to set up the build environment. The options include
install.batorinstall.ps1for Windows, andinstall.shorinstall.fishfor Unix shells. - Run the export script on Windows (
export.bat) or source it on Unix (source export.sh) in every shell environment before using ESP-IDF.
Configuring the Project
idf.py set-target <chip_name>sets the target of the project to<chip_name>. Runidf.py set-targetwithout any arguments to see a list of supported targets.idf.py menuconfigopens a text-based configuration menu where you can configure the project.
Compiling the Project
idf.py build
... will compile app, bootloader and generate a partition table based on the config.
Flashing the Project
When the build finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this automatically by running:
idf.py -p PORT flash
Replace PORT with the name of your serial port (like COM3 on Windows, /dev/ttyUSB0 on Linux, or /dev/cu.usbserial-X on MacOS. If the -p option is left out, idf.py flash will try to flash the first available serial port.
This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with idf.py menuconfig.
You don't need to run idf.py build before running idf.py flash, idf.py flash will automatically rebuild anything which needs it.
Viewing Serial Output
The idf.py monitor target uses the esp-idf-monitor tool to display serial output from Espressif SoCs. esp-idf-monitor also has a range of features to decode crash output and interact with the device. Check the documentation page for details.
Exit the monitor by typing Ctrl-].
To build, flash and monitor output in one pass, you can run:
idf.py flash monitor
Compiling & Flashing Only the App
After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:
idf.py app- build just the app.idf.py app-flash- flash just the app.
idf.py app-flash will automatically rebuild the app if any source files have changed.
(In normal development there's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
Erasing Flash
The idf.py flash target does not erase the entire flash contents. However it is sometimes useful to set the device back to a totally erased state, particularly when making partition table changes or OTA app updates. To erase the entire flash, run idf.py erase-flash.
This can be combined with other targets, ie idf.py -p PORT erase-flash flash will erase everything and then re-flash the new app, bootloader and partition table.
Resources
-
Documentation for the latest version: https://docs.espressif.com/projects/esp-idf/. This documentation is built from the docs directory of this repository.
-
The esp32.com forum is a place to ask questions and find community resources.
-
Check the Issues section on github if you find a bug or have a feature request. Please check existing Issues before opening a new one.
-
If you're interested in contributing to ESP-IDF, please check the Contributions Guide.