Add support for stm32mp2 SoC family

Add support for STM32MP2 SoC A35 core and stm32mp25-ev1 board.

Supports HYP and SMP configurations
-DPLATFORM=stm32mp2 -DKernelARMlatform=stm32mp257f-ev1 (default)

Supports MCS configuration (for Microkit build)

Signed-off-by: Christian Bruel <christian.bruel@foss.st.com>

libsel4/sel4_plat_include/stm32mp2/sel4/plat/api/constants.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2026, STMicroelectronics
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <sel4/config.h>
+#include <sel4/arch/constants_cortex_a35.h>
+
+#ifdef CONFIG_ARCH_AARCH32
+#error "AARCH32 is unsupported"
+#endif

src/drivers/serial/config.cmake

@@ -21,3 +21,5 @@ register_driver(compatibility_strings "qcom,msm-uartdm" PREFIX src/drivers/seria
 register_driver(compatibility_strings "xlnx,xuartps" PREFIX src/drivers/serial CFILES "xuartps.c")
 register_driver(compatibility_strings "amlogic,meson-gx-uart" PREFIX src/drivers/serial
                 CFILES "meson-gx-uart.c")
+register_driver(compatibility_strings "st,stm32h7-uart" PREFIX src/drivers/serial
+                CFILES "stm32h7-uart.c")

src/drivers/serial/stm32h7-uart.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2026, STMicroelectronics
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <config.h>
+#include <stdint.h>
+#include <util.h>
+#include <machine/io.h>
+#include <plat/machine/devices_gen.h>
+
+#define USART_ISR               0x1C
+#define USART_TDR               0x28
+
+#define USART_ISR_TXE           0x80U
+
+#define UART_REG(x) ((volatile uint32_t *)(UART_PPTR + (x)))
+
+#ifdef CONFIG_PRINTING
+void uart_drv_putchar(unsigned char c)
+{
+    while (!(*UART_REG(USART_ISR) & USART_ISR_TXE));
+    *UART_REG(USART_TDR) = c;
+}
+#endif /* CONFIG_PRINTING */
+
+#ifdef CONFIG_DEBUG_BUILD
+unsigned char uart_drv_getchar(void)
+{
+    return -1;
+}
+#endif /* CONFIG_DEBUG_BUILD */

src/plat/stm32mp2/config.cmake

@@ -0,0 +1,46 @@
+#
+# Copyright 2026, STMicroelectronics
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
+declare_platform(stm32mp2 KernelPlatformMP2 PLAT_STM32MP2 KernelSel4ArchAarch64)
+
+set(c_configs PLAT_STM32MP25_EV1)
+set(cmake_configs KernelPlatformMP25_EV1)
+set(plat_lists stm32mp257f-ev1)
+foreach(config IN LISTS cmake_configs)
+  unset(${config} CACHE)
+endforeach()
+
+if(KernelPlatformMP2)
+  declare_seL4_arch(aarch64)
+
+  check_platform_and_fallback_to_default(KernelARMPlatform "stm32mp257f-ev1")
+
+  list(FIND plat_lists ${KernelARMPlatform} index)
+  if("${index}" STREQUAL "-1")
+    message(FATAL_ERROR "Which stm32mp2 platform not specified ${KernelARMPlatform}")
+  endif()
+
+  list(GET c_configs ${index} c_config)
+  list(GET cmake_configs ${index} cmake_config)
+  config_set(${cmake_config} ${c_config} ON)
+  list(APPEND KernelDTSList "tools/dts/${KernelARMPlatform}.dts")
+  list(APPEND KernelDTSList "src/plat/stm32mp2/overlay-stm32mp2.dts")
+
+  set(KernelArmCortexA35 ON)
+  set(KernelArchArmV8a ON)
+  set(KernelArmGicV2 ON)
+
+  message(STATUS "KernelARMPlatform is ${KernelARMPlatform}")
+  config_set(KernelARMPlatform ARM_PLAT ${KernelARMPlatform})
+  config_set(KernelARMMach MACH "stm32mp2")
+
+  declare_default_headers(
+    TIMER_FREQUENCY 40000000 NUM_PPI 32 MAX_IRQ 415 INTERRUPT_CONTROLLER arch/machine/gic_v2.h
+    TIMER drivers/timer/arm_generic.h KERNEL_WCET 10u)
+endif()
+
+add_sources(DEP "KernelPlatformMP2" CFILES src/arch/arm/machine/gic_v2.c
+                                           src/arch/arm/machine/l2c_nop.c)

src/plat/stm32mp2/overlay-stm32mp2.dts

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2026, STMicroelectronics
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+/ {
+	chosen {
+		seL4,elfloader-devices =
+		    "serial0",
+		    &{/psci};
+
+		seL4,kernel-devices =
+		    "serial0",
+		    &{/interrupt-controller@4ac00000},
+		    &{/timer};
+	};
+
+	/* vgic maintenance interrupt */
+	interrupt-controller@4ac00000 {
+		interrupt-parent = <0x05>;
+		interrupts = <0x01 0x09 0x308>;
+	};
+};

tools/hardware.yml

@@ -191,6 +191,7 @@ devices:
       - qcom,msm-uartdm
       - samsung,exynos4210-uart
       - snps,dw-apb-uart
+      - st,stm32h7-uart
       - ti,omap3-uart
       - xlnx,xuartps
       - ns16550a