[arch|board]/risc-v: Allow BSS segments on PSRAM for ESP32-P4

This commits enables moving BSS data segments to the external PSRAM
on ESP32-P4. This is controlled by a Kconfig option.

Signed-off-by: Tiago Medicci Serrano <tiago.medicci@espressif.com>

arch/risc-v/src/common/espressif/CMakeLists.txt

@@ -213,7 +213,7 @@ if(DEFINED ENV{ESP_HAL_3RDPARTY_VERSION})
       CACHE STRING "ESP HAL 3rdparty version")
 else()
   set(ESP_HAL_3RDPARTY_VERSION
-      e10e44f52e41aee7a617b4d144982a1998a17fc5
+      627f38f94c1084b6b2d90ce09c0ce5517e8eaed7
       CACHE STRING "ESP HAL 3rdparty version")
 endif()
 

arch/risc-v/src/common/espressif/Kconfig

@@ -61,6 +61,7 @@ config ESPRESSIF_SPIRAM_BOOT_INIT
 
 config ESPRESSIF_SPIRAM_IGNORE_NOTFOUND
 	bool "Ignore SPIRAM not found"
+	depends on !ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
 	default n
 	---help---
 		Keep booting even if PSRAM detection fails.
@@ -118,6 +119,19 @@ config ESPRESSIF_SPIRAM_USER_HEAP
 	---help---
 		Add SPIRAM as an additional NuttX heap region.
 
+config ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
+	bool "Allow .bss segment placed in external memory"
+	default n
+	---help---
+		If enabled, variables with EXT_RAM_BSS_ATTR attribute will be
+		placed in SPIRAM instead of internal DRAM.
+
+		BSS sections from esp-hal-3rdparty components can also be placed
+		in SPIRAM through linker fragment mappings when enabled.
+
+		Note that variables placed in SPIRAM this way are still
+		zero-initialized at startup.
+
 endif # ESPRESSIF_SPIRAM
 
 config ESPRESSIF_IDF_ENV_FPGA

arch/risc-v/src/common/espressif/Make.defs

@@ -221,7 +221,7 @@ endif
 
 ESP_HAL_3RDPARTY_REPO   = esp-hal-3rdparty
 ifndef ESP_HAL_3RDPARTY_VERSION
-	ESP_HAL_3RDPARTY_VERSION = e10e44f52e41aee7a617b4d144982a1998a17fc5
+	ESP_HAL_3RDPARTY_VERSION = 627f38f94c1084b6b2d90ce09c0ce5517e8eaed7
 endif
 
 ifndef ESP_HAL_3RDPARTY_URL

arch/risc-v/src/common/espressif/esp_start.c

@@ -506,6 +506,7 @@ void __esp_start(void)
 #else
   bootloader_clear_bss_section();
 #endif
+
   /* Initialize the per CPU areas */
 
 #ifdef CONFIG_RISCV_PERCPU_SCRATCH
@@ -605,6 +606,10 @@ void __esp_start(void)
     }
 #endif
 
+#ifdef CONFIG_ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
+  esp_psram_bss_init();
+#endif
+
   /* Disable clock of unused peripherals */
 
   esp_perip_clk_init();

boards/risc-v/esp32p4/common/scripts/esp32p4_sections.ld

@@ -20,6 +20,8 @@
  *
  ****************************************************************************/
 
+#include <nuttx/config.h>
+
 /* Default entry point: */
 
 ENTRY(__start);
@@ -683,13 +685,26 @@ SECTIONS
      */
     *(.bss .bss.*)
     *(.dynbss .dynsbss .gnu.linkonce.b .gnu.linkonce.b.* .gnu.linkonce.sb .gnu.linkonce.sb.* .gnu.linkonce.sb2 .gnu.linkonce.sb2.* .sbss .sbss.* .sbss2 .sbss2.* .scommon .share.mem)
+#ifndef CONFIG_ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
     *(.ext_ram.bss .ext_ram.bss.*)
+#endif
     *(COMMON)
 
  . = ALIGN(4);
  _bss_end_high = ABSOLUTE(.);
   } > sram_high
 
+#ifdef CONFIG_ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
+  /* This section holds .ext_ram.bss data and places it in external RAM. */
+  .ext_ram.bss (NOLOAD) :
+  {
+    _ext_ram_bss_start = ABSOLUTE(.);
+    *(.ext_ram.bss .ext_ram.bss.*)
+    . = ALIGN(4);
+    _ext_ram_bss_end = ABSOLUTE(.);
+  } > ext_ram_seg
+#endif
+
   /* Heap region for sram_high: from end of bss to end of sram_high segment */
   _sram_high_heap_start = _bss_end_high;
   _sram_high_heap_end = ORIGIN(sram_high) + LENGTH(sram_high);

boards/risc-v/esp32p4/common/scripts/esp32p4_sections.rev3.ld

@@ -20,6 +20,8 @@
  *
  ****************************************************************************/
 
+#include <nuttx/config.h>
+
 /* Default entry point: */
 
 ENTRY(__start);
@@ -526,7 +528,9 @@ SECTIONS
     *(COMMON)
 
     *(.dynbss .dynsbss .gnu.linkonce.b .gnu.linkonce.b.* .gnu.linkonce.sb .gnu.linkonce.sb.* .gnu.linkonce.sb2 .gnu.linkonce.sb2.* .sbss .sbss.* .sbss2 .sbss2.* .scommon .share.mem)
+#ifndef CONFIG_ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
     *(.ext_ram.bss .ext_ram.bss.*)
+#endif
 
     . = ALIGN(4);
     _ebss = ABSOLUTE(.);
@@ -538,6 +542,17 @@ SECTIONS
     _bss_end = ABSOLUTE(.);
   } > sram_seg
 
+#ifdef CONFIG_ESPRESSIF_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
+  /* This section holds .ext_ram.bss data and places it in external RAM. */
+  .ext_ram.bss (NOLOAD) :
+  {
+    _ext_ram_bss_start = ABSOLUTE(.);
+    *(.ext_ram.bss .ext_ram.bss.*)
+    . = ALIGN(4);
+    _ext_ram_bss_end = ABSOLUTE(.);
+  } > ext_ram_seg
+#endif
+
   .flash.text :
   {
     _stext = .;