adds newlib-nano settings

env/common-gcc.mk

@@ -6,14 +6,15 @@ TL_TARGET?=all
 .PHONY: $(TL_TARGET)
 $(TL_TARGET): $(TARGET)
 
+ENV_DIR:=$(dir $(lastword $(MAKEFILE_LIST)))
+BSP_BASE=$(ENV_DIR)/..
+PLATFORM_DIR = $(ENV_DIR)/$(BOARD)
+
 include $(BSP_BASE)/libwrap/libwrap.mk
 
 BOARD?=iss
-ENV_DIR = $(BSP_BASE)/env
-PLATFORM_DIR = $(ENV_DIR)/$(BOARD)
 
-ASM_SRCS += $(ENV_DIR)/start.S
+ASM_SRCS += $(ENV_DIR)/start.S $(ENV_DIR)/entry.S
-ASM_SRCS += $(ENV_DIR)/entry.S
 C_SRCS   += $(PLATFORM_DIR)/init.c
 
 LINKER_SCRIPT ?= $(PLATFORM_DIR)/$(LINK_TARGET).lds
@@ -26,7 +27,13 @@ INCLUDES += -I$(PLATFORM_DIR)
 LDFLAGS += -march=$(RISCV_ARCH) -mabi=$(RISCV_ABI)
 LDFLAGS += -L$(ENV_DIR)
 LD_SCRIPT += -T $(LINKER_SCRIPT) -Wl,--no-warn-rwx-segments -Wl,-Map=$(TARGET).map  -nostartfiles 
-# --specs=nano.specs
+
+ifneq (,$(findstring specs=nano.specs,$(LDFLAGS), LD_SCRIPT))
+    # Found
+else
+    # Not found
+endif
+
 
 ASM_OBJS := $(ASM_SRCS:.S=.o)
 C_OBJS   := $(C_SRCS:.c=.o)
@@ -57,7 +64,8 @@ OBJCOPY := $(TOOL_DIR)$(TRIPLET)-objcopy
 
 ifndef NO_DEFAULT_LINK
 $(TARGET).elf: $(LINK_OBJS) $(LINK_DEPS)
-	$(LD) $(LINK_OBJS) $(LDFLAGS) $(LIBWRAP) $(LD_SCRIPT) -o $@
+	echo LINK_OBJS: $(LINK_OBJS)
+	$(LD) $(LINK_OBJS) $(LDFLAGS) $(LIBWRAP_LDFLAGS) $(LIBWRAP) $(LD_SCRIPT) -o $@
 	$(OBJDUMP) -d -S $@ > $(TARGET).dis
 endif
 

libwrap/libwrap.mk

@@ -59,9 +59,9 @@ LIBWRAP := libwrap.a
 
 LINK_DEPS += $(LIBWRAP)
 
-LDFLAGS += $(foreach s,$(LIBWRAP_SYMS),-Wl,--wrap=$(s))
+LIBWRAP_LDFLAGS += $(foreach s,$(LIBWRAP_SYMS),-Wl,--wrap=$(s))
-#LDFLAGS += $(foreach s,$(LIBWRAP_SYMS),-Wl,--wrap=_$(s))
+#LIBWRAP_LDFLAGS += $(foreach s,$(LIBWRAP_SYMS),-Wl,--wrap=_$(s))
-LDFLAGS += -L. -Wl,--start-group -lwrap -lc -Wl,--end-group
+LIBWRAP_LDFLAGS += -L. -Wl,--start-group -lwrap -lc -Wl,--end-group
 
 CLEAN_OBJS += $(LIBWRAP_OBJS)
 

newlib-nano/.gitignore

@@ -0,0 +1 @@
+/*.o

newlib-nano/lib.mk

@@ -0,0 +1,16 @@
+#CFLAGS+=--specs=nano.specs
+#LDFLAGS+=--specs=nano.specs
+#CFLAGS+=--specs=rv32imac/ilp32/nano.specs
+#LDFLAGS+=--specs=rv32imac/ilp32/nano.specs
+
+NANO_LIB_DIR := $(dir $(lastword $(MAKEFILE_LIST)))
+NANO_LIB_SYMS := read write syscalls
+
+NANO_LIB_SRCS := $(foreach s,$(NANO_LIB_SYMS),$(NANO_LIB_DIR)/$(s).c)
+#NANO_LIB_SRCS := $(foreach f,$(LIB_SRCS),$(LIB_DIR)/$(f))
+NANO_LIB_OBJS := $(NANO_LIB_SRCS:.c=.o)
+
+CLEAN_OBJS += $(NANO_LIB_OBJS)
+
+$(NANO_LIB_OBJS): %.o: %.c $(HEADERS)
+	$(CC) $(CFLAGS) $(INCLUDES) -c -o $@ $<

newlib-nano/read.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include "stub.h"
+#include <platform.h>
+
+ssize_t _read(int fd, void* ptr, size_t len);
+
+ssize_t _read(int fd, void* ptr, size_t len) {
+  uint8_t * current = (uint8_t *)ptr;
+  ssize_t result = 0;
+  if (isatty(fd)) {
+    for (current = (uint8_t *)ptr;
+        (current < ((uint8_t *)ptr) + len) && (uart_get_rx_avail(uart) > 0);
+        current ++) {
+      *current = uart_read(uart);
+      result++;
+    }
+    return result;
+  }
+  return _stub(EBADF);
+}

newlib-nano/stub.h

@@ -0,0 +1,8 @@
+#ifndef _LIBWRAP_STUB_H_
+#define _LIBWRAP_STUB_H_
+
+static inline int _stub(int err) {
+  return err?-1:-1;
+}
+
+#endif /* _LIBWRAP_STUB_H_ */

newlib-nano/syscalls.c

@@ -0,0 +1,79 @@
+#include <unistd.h>
+#include <sys/stat.h>
+
+extern int _end;
+void* _sbrk(int incr);
+int _close(int file);
+int _fstat(int file, struct stat *st);
+int _isatty(int fd);
+int _lseek(int file, int ptr, int dir);
+
+void _kill(int pid, int sig);
+int _getpid(void);
+void write_hex(int fd, unsigned long int hex);
+
+void *_sbrk(int incr) {
+  static unsigned char *heap = NULL;
+  unsigned char *prev_heap;
+  if (heap == NULL) {
+    heap = (unsigned char *)&_end;
+  }
+  prev_heap = heap;
+  heap += incr;
+  return prev_heap;
+}
+
+int _close(int file) {
+  (void)file;
+  return -1;
+}
+
+int _fstat(int file, struct stat *st) {
+  (void)file;
+  st->st_mode = S_IFCHR;
+  return 0;
+}
+
+int _isatty(int fd) {
+  if (fd == STDOUT_FILENO || fd == STDERR_FILENO)
+    return 1;
+  return 0;
+}
+
+int _lseek(int file, int ptr, int dir) {
+  (void)file;
+  (void)ptr;
+  (void)dir;
+  return 0;
+}
+
+void _exit(int status) {
+  const char message[] = "\nProgam has exited with code:";
+  write(STDERR_FILENO, message, sizeof(message) - 1);
+  write_hex(STDERR_FILENO, status);
+  write(STDERR_FILENO, "\n", 1);
+  for (;;);
+}
+
+void _kill(int pid, int sig) {
+  (void)pid;
+  (void)sig;
+  return;
+}
+
+int _getpid(void) {
+  return -1;
+}
+
+void write_hex(int fd, unsigned long int hex){
+  uint8_t ii;
+  uint8_t jj;
+  char towrite;
+  write(fd , "0x", 2);
+  for (ii = sizeof(unsigned long int) * 2 ; ii > 0; ii--) {
+    jj = ii - 1;
+    uint8_t digit = ((hex & (0xF << (jj*4))) >> (jj*4));
+    towrite = digit < 0xA ? ('0' + digit) : ('A' +  (digit - 0xA));
+    write(fd, &towrite, 1);
+  }
+}

newlib-nano/write.c

@@ -0,0 +1,24 @@
+#include <stdint.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include "stub.h"
+#include <platform.h>
+
+ssize_t _write(int fd, const void* ptr, size_t len);
+
+ssize_t _write(int fd, const void* ptr, size_t len) {
+  const char * current = (const char *)ptr;
+  if (isatty(fd)) {
+    for (size_t jj = 0; jj < len; jj++) {
+      while (uart_get_tx_free(uart)==0) ;
+      uart_write(uart, current[jj]);
+      if (current[jj] == '\n') {
+        while (uart_get_tx_free(uart)==0) ;
+        uart_write(uart, '\r');
+      }
+    }
+    return len;
+  }
+  return _stub(EBADF);
+}