Update flash size

[SergioGasquez]

With this PR we will update the flash size in the following order:

1. Provided by --flash-size arg
2. Config file
3. Detect if we can (if we are flashing we can try to detect, but save-image cant)
4. Used the default flash size: 4Mb

We have to pass flasher arround which is not ideal... I initially though of cfef334 but that results in lots of duplicated code.

Tests

I generated an std template: cargo generate esp-rs/esp-idf-template cargo for S3 and with the default configurations. Updated the code to:

// Define a large static array (roughly 1MB)
// 1MB = 1 * 1024 * 1024 bytes
static LARGE_ARRAY: [u8; 1 * 1024 * 1024] = [0; 1 * 1024 * 1024];

fn main() {
    // It is necessary to call this function once. Otherwise some patches to the runtime
    // implemented by esp-idf-sys might not link properly. See https://github.com/esp-rs/esp-idf-template/issues/71
    esp_idf_svc::sys::link_patches();

    // Bind the log crate to the ESP Logging facilities
    esp_idf_svc::log::EspLogger::initialize_default();

    // Access the array to prevent it from being optimized away
    log::info!("Hello, world! Array size: {} bytes", LARGE_ARRAY.len());
    log::info!("First byte: {}", LARGE_ARRAY[0]);
}

When building this, we get the following elf:

❯ eza -l target/xtensa-esp32s3-espidf/release/app-size
.rwxr-xr-x 1.8M sergio 28 Feb 15:41 target/xtensa-esp32s3-espidf/release/app-size

When triying to flash it with [email protected] (installed a few days ago):

❯ espflash flash target/xtensa-esp32s3-espidf/release/app-size
[2025-02-28T14:52:13Z INFO ] Serial port: '/dev/ttyUSB1'
[2025-02-28T14:52:13Z INFO ] Connecting...
[2025-02-28T14:52:13Z INFO ] Using flash stub
[2025-02-28T14:52:14Z WARN ] Setting baud rate higher than 115,200 can cause issues
Chip type:         esp32s3 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        8MB
Features:          WiFi, BLE
MAC address:       60:55:f9:f5:20:d4
Error: espflash::image_too_big (link)

  × Supplied ELF image of 1455472B is too big, and doesn't fit configured app partition of 1048576B
  help: Reduce the size of the binary or increase the size of the app partition.

When using this patch:

❯ cargo r -r --bin espflash -- flash /home/sergio/Documents/Espressif/tests/app-size/target/xtensa-esp32s3-espidf/release/app-size
    Finished `release` profile [optimized] target(s) in 0.12s
     Running `target/release/espflash flash /home/sergio/Documents/Espressif/tests/app-size/target/xtensa-esp32s3-espidf/release/app-size`
[2025-02-28T14:53:51Z INFO ] Serial port: '/dev/ttyUSB1'
[2025-02-28T14:53:51Z INFO ] Connecting...
[2025-02-28T14:53:51Z INFO ] Using flash stub
[2025-02-28T14:53:52Z WARN ] Setting baud rate higher than 115,200 can cause issues
Chip type:         esp32s3 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        8MB
Features:          WiFi, BLE
MAC address:       60:55:f9:f5:20:d4
App/part. size:    1,455,472/8,323,072 bytes, 17.49%
[00:00:00] [========================================]      14/14      0x0                                                                                                                                                                                   
[00:00:00] [========================================]       1/1       0x8000                                                                                                                                                                                
[00:00:15] [========================================]     235/235     0x10000                                                                                                                                                                               [2025-02-28T14:54:18Z INFO ] Flashing has completed!

espflash on  feat/flash-size [$] via 🦀 v1.87.0-nightly took 27s 

[jessebraham]

Thanks for the PR! Also don't love that we have to pass around Flasher here, will try to see if I can think of any other way to accomplish this.

[jessebraham]

Thanks, LGTM!