esp32: Allow malloc() to allocate from SPIRAM.

projectgus · projectgus · commit 8322afccab13 · 2023-08-01T16:51:36.000+10:00
- Also shrinks the "prefer internal" threshold to 8KB,
  any allocation larger than this will try PSRAM first.

- Change the mbedTLS config to use regular malloc() as
  well, instead of internal only. The default is set
  to internal-only due to  to potential readout via
  PSRAM on ESP32. However, as MicroPython runs from plaintext
  flash and all other context is in the MP heap of PSRAM
  then it's hard to see how worsens physical security for MP.

Signed-off-by: Angus Gratton &lt;angus@redyak.com.au&gt;
diff --git a/ports/esp32/boards/sdkconfig.base b/ports/esp32/boards/sdkconfig.base
@@ -49,6 +49,9 @@ CONFIG_LWIP_PPP_CHAP_SUPPORT=y
 # Use 4kiB output buffer instead of default 16kiB
 CONFIG_MBEDTLS_ASYMMETRIC_CONTENT_LEN=y
 
+# Allow mbedTLS to allocate from PSRAM or internal memory
+CONFIG_MBEDTLS_DEFAULT_MEM_ALLOC=y
+
 # ULP coprocessor support
 # Only on: ESP32, ESP32S2, ESP32S3
 CONFIG_ULP_COPROC_ENABLED=y
diff --git a/ports/esp32/boards/sdkconfig.spiram b/ports/esp32/boards/sdkconfig.spiram
@@ -3,7 +3,8 @@
 CONFIG_SPIRAM=y
 CONFIG_SPIRAM_CACHE_WORKAROUND=y
 CONFIG_SPIRAM_IGNORE_NOTFOUND=y
-CONFIG_SPIRAM_USE_CAPS_ALLOC=y
+CONFIG_SPIRAM_USE_MALLOC=y
+CONFIG_SPIRAM_MALLOC_ALWAYSINTERNAL=8192
 
 # SPIRAM increases the size of the firmware and overflows iram0_0_seg, due
 # to PSRAM bug workarounds.  Apply some options to reduce the firmware size.
diff --git a/ports/esp32/boards/sdkconfig.spiram_sx b/ports/esp32/boards/sdkconfig.spiram_sx
@@ -7,4 +7,5 @@ CONFIG_SPIRAM_SPEED_80M=y
 CONFIG_SPIRAM=y
 CONFIG_SPIRAM_BOOT_INIT=y
 CONFIG_SPIRAM_IGNORE_NOTFOUND=y
-CONFIG_SPIRAM_USE_CAPS_ALLOC=y
+CONFIG_SPIRAM_USE_MALLOC=y
+CONFIG_SPIRAM_MALLOC_ALWAYSINTERNAL=8192
