espressif: esp32c5/esp32s3: fix PSRAM + Wi-Fi heap mapping and linker segment sizing bugs #109602

Describe the bug

When building any sample that exercises the Espressif Wi-Fi driver with PSRAM enabled (CONFIG_ESP_SPIRAM=y + CONFIG_ESP_WIFI_HEAP_SPIRAM=y), the board resets early in boot or shortly after the Wi-Fi blob starts running. The reset happens silently, with no panic dump, and the bootloader log keeps cycling.

This issue affects all PSRAM-capable Espressif SoCs (esp32, esp32s2, esp32s3, esp32c5) but only manifests when .ext_ram.data has content ahead of the heap window, e.g. with CONFIG_ESP32_WIFI_NET_ALLOC_SPIRAM=y. On esp32c5, an additional gap was present because the ESP32_WIFI_NET_ALLOC_SPIRAM linker block was never ported from esp32/esp32s2/esp32s3.

Regression

• This is a regression.

Steps to reproduce

west build -p auto -b esp32c5_devkitc/esp32c5/hpcore samples/net/wifi/shell
-DCONFIG_ESP_SPIRAM=y
-DCONFIG_ESP_WIFI_HEAP_SPIRAM=y

The Wi-Fi shell sample boots into the Zephyr shell. wifi scan and wifi connect work. Wi-Fi buffers are allocated from PSRAM (with internal SRAM as fallback when PSRAM is exhausted).

Relevant log output

Impact

Annoyance – Minor irritation; no significant impact on usability or functionality.

Environment

OS: Linux
Toolchain: Zephyr SDK 1.0.1 (xtensa-espressif_esp32s3_zephyr-elf, riscv64-zephyr-elf)
Commit: current main and in v4.4.0

Additional Context

No response