Build: Add hightec toolchain and picolibc stub function support

Signed-off-by: Huaqi Fang <[email protected]>

Build/Makefile.conf

@@ -6,6 +6,11 @@ ifdef STDCLIB
 override NEWLIB := $(STDCLIB)
 endif
 
+# TODO workaround for forcing to use picolibc for hightec toolchain
+ifeq ($(TOOLCHAIN),hightec)
+override STDCLIB := picolibc_small
+endif
+
 include $(NUCLEI_SDK_BUILD)/Makefile.files
 include $(NUCLEI_SDK_NMSIS)/build.mk
 include $(NUCLEI_SDK_BUILD)/Makefile.soc

Build/toolchain/hightec.mk

@@ -0,0 +1,79 @@
+CC      := clang
+CXX     := clang
+OBJDUMP := llvm-objdump
+OBJCOPY := llvm-objcopy
+# use gnu gdb to debug or upload
+GDB     := riscv64-unknown-elf-gdb
+AR      := llvm-ar
+SIZE    := llvm-size
+OPENOCD := openocd
+
+# Hightec toolchain use picolibc as c library
+# TODO: The stub function is totally different from newlib stub function, take care
+
+# Handle standard c library selection variable STDCLIB
+ifneq ($(findstring picolibc,$(STDCLIB)),)
+### Handle cases when STDCLIB variable has picolibc in it
+LDLIBS += -lc
+STDCLIB_LDFLAGS +=
+###
+else ifeq ($(STDCLIB),nostd)
+### Handle cases when no standard system directories for header files
+COMMON_FLAGS += -nostdinc
+###
+else ifeq ($(STDCLIB),nospec)
+### Handle cases no specs configs are passed
+COMMON_FLAGS +=
+###
+else
+LDLIBS += -lc
+STDCLIB_LDFLAGS +=
+###
+endif
+
+ifneq ($(SEMIHOST),)
+LDLIBS += -lsemihost
+endif
+
+## Link with standard c++ library
+LDLIBS +=
+
+
+## TODO: Specical handling for RV32 or RV64 clang_rt library selection
+ifneq ($(findstring 32,$(RISCV_ABI)),)
+LDLIBS += -lclang_rt.builtins-riscv32
+else
+LDLIBS += -lclang_rt.builtins-riscv64
+endif
+
+## Heap and stack size settings
+## It will define symbols only used in linker script
+## __STACK_SIZE and __HEAP_SIZE are not a c marco
+## they are ld symbols used by linker
+ifneq ($(STACKSZ),)
+LDFLAGS += -Wl,--defsym=__STACK_SIZE=$(STACKSZ)
+endif
+ifneq ($(HEAPSZ),)
+LDFLAGS += -Wl,--defsym=__HEAP_SIZE=$(HEAPSZ)
+endif
+
+## SIMU=xlspike/qemu
+### enable run on xlspike and qemu auto-exit if return from main
+ifneq ($(SIMU),)
+SIMULATION_MODE=SIMULATION_MODE_$(call uc, $(SIMU))
+COMMON_FLAGS += -DSIMULATION_MODE=$(SIMULATION_MODE)
+endif
+
+COMMON_FLAGS += -march=$(RISCV_ARCH) -mabi=$(RISCV_ABI) -mcmodel=$(RISCV_CMODEL)
+COMMON_FLAGS += -fno-exceptions
+## Append mtune options when RISCV_TUNE is defined
+## It might be defined in SoC/<SOC>/build.mk, and can be overwritten by make
+ifneq ($(RISCV_TUNE),)
+COMMON_FLAGS +=# -mtune=$(RISCV_TUNE)
+endif
+
+ifneq ($(findstring picolibc,$(STDCLIB)),)
+LDFLAGS += #-u __on_exit_args
+endif
+
+LDFLAGS += -nodefaultlibs

SoC/evalsoc/Common/Source/Stubs/picolibc/stubs.c

@@ -0,0 +1,204 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright © 2022 Keith Packard
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials provided
+ *    with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <nuclei_sdk_hal.h>
+
+#undef errno
+#ifndef NEWLIB_THREAD_LOCAL_ERRNO
+#define NEWLIB_THREAD_LOCAL_ERRNO
+#endif
+NEWLIB_THREAD_LOCAL_ERRNO int errno;
+
+#undef putchar
+
+int putchar(int dat)
+{
+    if (dat == '\n') {
+        uart_write(SOC_DEBUG_UART, '\r');
+    }
+    uart_write(SOC_DEBUG_UART, dat);
+    return dat;
+}
+
+// #define UART_AUTO_ECHO
+
+#undef getchar
+
+int getchar(void)
+{
+    int dat;
+
+    dat = (int)uart_read(SOC_DEBUG_UART);
+#ifdef UART_AUTO_ECHO
+    uart_write(SOC_DEBUG_UART, (uint8_t)dat);
+#endif
+    return dat;
+}
+
+#ifdef TINY_STDIO
+
+static int __stdio_putc(char c, FILE *file)
+{
+    (void)file;
+    return putchar((int)c);
+}
+
+// #define UART_AUTO_ECHO
+
+static int __stdio_getc(FILE *file)
+{
+    (void)file;
+    return getchar();
+}
+
+static FILE __stdio =
+    FDEV_SETUP_STREAM(__stdio_putc, __stdio_getc, NULL, _FDEV_SETUP_RW);
+
+#ifdef __strong_reference
+#define STDIO_ALIAS(x) __strong_reference(stdin, x);
+#else
+#define STDIO_ALIAS(x) FILE *const x = &__stdio;
+#endif
+
+FILE *const stdin = &__stdio;
+STDIO_ALIAS(stdout);
+STDIO_ALIAS(stderr);
+
+#endif
+
+ssize_t read(int fd, void *buf, size_t count)
+{
+    (void)fd;
+    ssize_t cnt = 0;
+    uint8_t* readbuf = (uint8_t*)buf;
+
+    for (cnt = 0; cnt < count; cnt ++) {
+        readbuf[cnt] = getchar();
+        /* Return partial buffer if we get EOL */
+        if (readbuf[cnt] == '\n') {
+            return cnt;
+        }
+    }
+
+    return cnt;
+}
+
+ssize_t write(int fd, const void *buf, size_t count)
+{
+    (void)buf;
+
+    const uint8_t* writebuf = (const uint8_t*)buf;
+    for (size_t i = 0; i < count; i++) {
+        putchar((int)writebuf[i]);
+    }
+    return (ssize_t)count;
+}
+
+
+void _ATTRIBUTE((__noreturn__)) _exit(int code)
+{
+    (void)code;
+    while (1) {
+    }
+}
+
+pid_t getpid(void)
+{
+    return 1;
+}
+
+int kill(pid_t pid, int sig)
+{
+    if (pid == 1)
+        _exit(128 + sig);
+    errno = ESRCH;
+    return -1;
+}
+
+int open(const char *pathname, int flags, ...)
+{
+    (void)pathname;
+    (void)flags;
+    return -1;
+}
+
+int close(int fd)
+{
+    (void)fd;
+    return 0;
+}
+
+off_t lseek(int fd, off_t offset, int whence)
+{
+    (void)fd;
+    (void)offset;
+    (void)whence;
+    return (off_t)-1;
+}
+
+_off64_t lseek64(int fd, _off64_t offset, int whence)
+{
+    return (_off64_t)lseek(fd, (off_t)offset, whence);
+}
+
+int unlink(const char *pathname)
+{
+    (void)pathname;
+    return 0;
+}
+
+int fstat(int fd, struct stat *sbuf)
+{
+    (void)fd;
+    (void)sbuf;
+    return -1;
+}
+
+int isatty(int fd)
+{
+    (void)fd;
+    return 1;
+}
+

SoC/evalsoc/build.mk

@@ -209,6 +209,8 @@ C_SRCDIRS += $(NUCLEI_SDK_SOC_COMMON)/Source $(NUCLEI_SDK_SOC_COMMON)/Source/Dri
 ifeq ($(SEMIHOST),)
 ifneq ($(findstring newlib,$(STDCLIB)),)
 C_SRCDIRS += $(NUCLEI_SDK_SOC_COMMON)/Source/Stubs/newlib
+else ifneq ($(findstring picolib,$(STDCLIB)),)
+C_SRCDIRS += $(NUCLEI_SDK_SOC_COMMON)/Source/Stubs/picolibc
 else
 # no stubs will be used
 endif