soc: st: stm32: h7rs: Add memory region to MPU region list

Add ethernet DMA buffer/descriptor region (sram2) and read only
flash region 0x08FFF800 with unique device ID registers to MPU region
list. The unique device ID is used to create a random mac address by
the ethernet driver. Ethernet DMA buffer/descriptor memory section is
also added to linker script.

Signed-off-by: Thomas Decker <[email protected]>

Author: TD-JBL

soc/st/stm32/stm32h7rsx/CMakeLists.txt

@@ -6,6 +6,7 @@ zephyr_sources(
   )
 
 zephyr_sources(mpu_regions.c)
+zephyr_linker_sources(SECTIONS sections.ld)
 
 zephyr_include_directories(.)
 

soc/st/stm32/stm32h7rsx/mpu_regions.c

@@ -26,6 +26,20 @@ static const struct arm_mpu_region mpu_regions[] = {
 
 	/* Region 3 */
 	MPU_REGION_ENTRY("SRAM_0", CONFIG_SRAM_BASE_ADDRESS, REGION_RAM_ATTR(REGION_SRAM_SIZE)),
+
+	/* Region 4 - Ready only flash with unique device id */
+	MPU_REGION_ENTRY("ID", 0x08FFF800, REGION_FLASH_ATTR(REGION_2K)),
+
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(mac))
+#define sram_eth_node DT_NODELABEL(sram2)
+#if DT_NODE_HAS_STATUS_OKAY(sram_eth_node)
+	/* Region 5 - Ethernet DMA buffer RAM */
+	MPU_REGION_ENTRY("SRAM_ETH_BUF", DT_REG_ADDR(sram_eth_node),
+			 REGION_RAM_NOCACHE_ATTR(REGION_16K)),
+	/* Region 6 - Ethernet DMA descriptor RAM (overlays the first 256B of SRAM_ETH_BUF)*/
+	MPU_REGION_ENTRY("SRAM_ETH_DESC", DT_REG_ADDR(sram_eth_node), REGION_PPB_ATTR(REGION_256B)),
+#endif
+#endif
 };
 
 const struct arm_mpu_config mpu_config = {

soc/st/stm32/stm32h7rsx/sections.ld

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2020 Mario Jaun
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(mac))
+#define sram_eth_node	DT_NODELABEL(sram2)
+#if DT_NODE_HAS_STATUS_OKAY(sram_eth_node)
+SECTION_DATA_PROLOGUE(eth_stm32,(NOLOAD),)
+{
+    . = ABSOLUTE(DT_REG_ADDR(sram_eth_node));
+    *(.eth_stm32_desc)
+    . = ABSOLUTE(DT_REG_ADDR(sram_eth_node)) + 256;
+    *(.eth_stm32_buf)
+    . = ABSOLUTE(DT_REG_ADDR(sram_eth_node)) + 16K;
+} GROUP_DATA_LINK_IN(LINKER_DT_NODE_REGION_NAME(sram_eth_node), LINKER_DT_NODE_REGION_NAME(sram_eth_node))
+#endif
+
+#endif /* DT_NODE_HAS_STATUS(DT_NODELABEL(mac), okay) */