arm: adapt to being built as multilib

Makefile

@@ -34,6 +34,13 @@ LIB_TARGETS := $(PREFIX_A)libphoenix.a $(PREFIX_A)crt0.o
 
 all: $(LIB_TARGETS)
 
+ifeq ($(TARGET_SUBFAMILY),multilib)
+  LIBPHOENIX_MULTILIB := y
+  CPPFLAGS += -DLIBPHOENIX_MULTILIB
+else
+  LIBPHOENIX_MULTILIB := n
+endif
+
 ifneq (,$(findstring arm,$(TARGET_SUFF)))
   include arch/arm/Makefile
 else ifneq (,$(findstring aarch64,$(TARGET_SUFF)))

arch/arm/Makefile

@@ -6,17 +6,34 @@
 # %LICENSE%
 #
 
-ifneq (,$(findstring v7a,$(TARGET_SUFF)))
+# Obtain architecture based on ARM ACLE 2.0
+# https://developer.arm.com/documentation/dui0774/l/Other-Compiler-specific-Features/Predefined-macros
+arm_version := $(word 3, $(shell echo | arm-phoenix-gcc $(CFLAGS) -E -dM - | grep -E "[[:space:]]__ARM_ARCH[[:space:]]"))
+arm_profile_num := $(word 3, $(shell echo | arm-phoenix-gcc $(CFLAGS) -E -dM - | grep -E "[[:space:]]__ARM_ARCH_PROFILE[[:space:]]"))
+# ASCII conversion
+arm_profile := $(subst 65,A,$(subst 77,M,$(subst 82,R,$(arm_profile_num))))
+arm_arch := $(arm_version)$(arm_profile)
+
+arm_use_common := y
+ifneq (,$(findstring 7A,$(arm_arch)))
   include arch/arm/v7a/Makefile
-else ifneq (,$(findstring v7m,$(TARGET_SUFF)))
+else ifneq (,$(findstring 7M,$(arm_arch)))
   include arch/arm/v7m/Makefile
-else ifneq (,$(findstring v8m,$(TARGET_SUFF)))
+else ifneq (,$(findstring 8M,$(arm_arch)))
   include arch/arm/v8m/Makefile
-else ifneq (,$(findstring v8r,$(TARGET_SUFF)))
+else ifneq (,$(findstring 8R,$(arm_arch)))
   include arch/arm/v8r/Makefile
+else ifeq ($(LIBPHOENIX_MULTILIB),y)
+  include arch/arm/multilib/Makefile
+  arm_use_common := n
 else
   $(error Unsupported TARGET)
 endif
 
+# FIXME: multilib supports more targets that functions in those files do,
+#        eg. arm/arch=armv5te or Thumb-1 targets (v6s-m and v8-m.base).
+ifeq ($(arm_use_common),y)
 OBJS += $(addprefix $(PREFIX_O)arch/arm/, jmp.o memcpy.o memset.o signal.o string.o)
+endif
+
 CRT0_OBJS += $(addprefix $(PREFIX_O)arch/arm/, crt0.o)

arch/arm/multilib/Makefile

@@ -0,0 +1,11 @@
+#
+# Makefile for libphoenix/arch/arm/multilib
+#
+# Copyright 2025 Phoenix Systems
+#
+# %LICENSE%
+#
+
+OBJS += $(addprefix $(PREFIX_O)arch/arm/multilib/, syscalls.o reboot.o)
+
+OBJS += $(addprefix $(PREFIX_O)arch/arm/multilib/, jmp.o signal.o string.o)

arch/arm/multilib/jmp.c

@@ -0,0 +1,42 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ *
+ * _setjmp, _longjmp, setjmp, sigsetjmp
+ *
+ * Copyright 2025 Phoenix Systems
+ * Author: Hubert Badocha
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#include <setjmp.h>
+#include <stdlib.h>
+
+
+int _setjmp(jmp_buf var)
+{
+	abort();
+}
+
+
+__attribute__((__noreturn__)) void _longjmp(jmp_buf var, int m)
+{
+	abort();
+}
+
+
+int setjmp(jmp_buf var)
+{
+	abort();
+}
+
+
+int sigsetjmp(sigjmp_buf env, int savesigs)
+{
+	abort();
+}

arch/arm/multilib/reboot.c

@@ -0,0 +1,31 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * reboot.c
+ *
+ * Copyright 2025 Phoenix Systems
+ * Author: Hubert Badocha
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#include <sys/reboot.h>
+#include <sys/platform.h>
+
+
+int reboot(int magic)
+{
+	return -1;
+}
+
+
+int reboot_reason(uint32_t *val)
+{
+	*val = 0u;
+
+	return 0;
+}

arch/arm/multilib/signal.S

@@ -0,0 +1,24 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * Signal trampoline (arm)
+ *
+ * Copyright 2025 Phoenix Systems
+ * Author: Hubert Badocha
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#define __ASSEMBLY__
+
+.text
+
+.globl _signal_trampoline
+.type _signal_trampoline, %function
+_signal_trampoline:
+	bl abort
+.size _signal_trampoline, .-_signal_trampoline

arch/arm/multilib/string.c

@@ -0,0 +1,127 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * arch/arm/multilib/string
+ *
+ * Copyright 2025 Phoenix Systems
+ * Author: Hubert Badocha
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+
+#include <stddef.h>
+
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+	for (size_t i = 0; i < n; i++) {
+		((char *)dest)[i] = ((const char *)src)[i];
+	}
+	return dest;
+}
+
+
+int memcmp(const void *ptr1, const void *ptr2, size_t n)
+{
+	for (size_t i = 0; i < n; i++) {
+		int diff = ((int)(((const unsigned char *)ptr1)[i])) - ((int)(((const unsigned char *)ptr2)[i]));
+		if (diff != 0) {
+			return diff;
+		}
+	}
+	return 0;
+}
+
+
+size_t strlen(const char *s)
+{
+	size_t len = 0;
+	while (s[len] != '\0') {
+		len++;
+	}
+	return len;
+}
+
+
+size_t strnlen(const char *s, size_t maxlen)
+{
+	size_t len = 0;
+	while ((s[len] != '\0') && (len < maxlen)) {
+		len++;
+	}
+	return len;
+}
+
+
+int strcmp(const char *s1, const char *s2)
+{
+	for (size_t i = 0; (s1[i] != '\0') || (s2[i] != '\0'); i++) {
+		int diff = ((int)(((const unsigned char *)s1)[i])) - ((int)(((const unsigned char *)s2)[i]));
+		if (diff != 0) {
+			return diff;
+		}
+	}
+	return 0;
+}
+
+
+int strncmp(const char *s1, const char *s2, size_t count)
+{
+	for (size_t i = 0; ((i < count) && ((s1[i] != '\0') || (s2[i] != '\0'))); i++) {
+		int diff = ((int)(((const unsigned char *)s1)[i])) - ((int)(((const unsigned char *)s2)[i]));
+		if (diff != 0) {
+			return diff;
+		}
+	}
+	return 0;
+}
+
+
+char *strcpy(char *dest, const char *src)
+{
+	size_t i = 0;
+	while ((src[i] != '\0')) {
+		dest[i] = src[i];
+		i++;
+	}
+	dest[i] = '\0';
+	return dest;
+}
+
+
+char *strncpy(char *dest, const char *src, size_t n)
+{
+	size_t i = 0;
+	while (((i < n) && (src[i] != '\0'))) {
+		dest[i] = src[i];
+		i++;
+	}
+	while (i < n) {
+		dest[i] = '\0';
+		i++;
+	}
+	return dest;
+}
+
+
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	for (size_t i = 0; i < n; i++) {
+		((char *)dest)[i] = ((const char *)src)[i];
+	}
+	return dest;
+}
+
+
+void *memset(void *dest, int value, size_t n)
+{
+	for (size_t i = 0; i < n; i++) {
+		((unsigned char *)dest)[i] = (unsigned char)value;
+	}
+	return dest;
+}

arch/arm/multilib/syscalls.S

@@ -0,0 +1,41 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * syscalls (arm-multilib)
+ *
+ * Copyright 2025 Phoenix Systems
+ * Author: Hubert Badocha
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#define __ASSEMBLY__
+#include <phoenix/syscalls.h>
+
+.text
+
+
+#define SYSCALLDEF(sym, sn) \
+.globl sym; \
+.type sym, %function; \
+sym: \
+	bl abort; \
+.size sym, .-sym
+
+
+.globl vfork;
+.type vfork, %function;
+vfork:
+	b vforksvc
+.size vfork, .-vfork
+
+
+#define SYSCALLS_LIBC(name) \
+	SYSCALLDEF(name, __COUNTER__);
+
+
+SYSCALLS(SYSCALLS_LIBC)

arch/arm/v7a/reboot.c

@@ -14,6 +14,25 @@
  */
 
 #include <sys/reboot.h>
+
+#if defined(LIBPHOENIX_MULTILIB)
+
+
+int reboot(int magic)
+{
+	return -1;
+}
+
+
+int reboot_reason(uint32_t *val)
+{
+	return -1;
+}
+
+
+#else
+
+
 #include <sys/platform.h>
 #if defined(__CPU_ZYNQ7000)
 #include <phoenix/arch/armv7a/zynq7000/zynq7000.h>
@@ -52,3 +71,5 @@ int reboot_reason(uint32_t *val)
 	*val = pctl.reboot.reason;
 	return 0;
 }
+
+#endif

arch/arm/v7m/reboot.c

@@ -14,6 +14,25 @@
  */
 
 #include <sys/reboot.h>
+
+#if defined(LIBPHOENIX_MULTILIB)
+
+
+int reboot(int magic)
+{
+	return -1;
+}
+
+
+int reboot_reason(uint32_t *val)
+{
+	return -1;
+}
+
+
+#else
+
+
 #include <sys/platform.h>
 
 #if defined(__CPU_STM32L4X6)
@@ -55,3 +74,5 @@ int reboot_reason(uint32_t *val)
 	*val = pctl.reboot.reason;
 	return 0;
 }
+
+#endif