add floating print to STM32F303

F303-nolib/floatPrintf/Makefile

@@ -0,0 +1,146 @@
+BINARY		= usart1
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F3
+# MCU code
+MCU			?= F303xb
+# or __ARM_ARCH_7EM__
+ARMARCH = __ARM_ARCH_7M__
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f303xB.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -mfpu=fpv4-sp-d16 -mfloat-abi=softfp -fsingle-precision-constant -mlittle-endian -DARM_MATH_CM4
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m4
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS) -D $(ARMARCH)
+
+###############################################################################
+# Executables
+# PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+#TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		:= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		:= $(OBJDIR)/startup.o
+MAP			:= $(OBJDIR)/$(BINARY).map
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -g -gdwarf-2   # debuggin symbols in listing
+CFLAGS		+= -O2 -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fshort-enums -ffunction-sections -fdata-sections
+#CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+#LDFLAGS		+= -nostartfiles --static -nostdlib  -specs=nosys.specs -specs=nano.specs
+LDFLAGS		+= $(ARCH_FLAGS)
+LDFLAGS		+= -specs=nano.specs -specs=nosys.specs
+LDFLAGS		+= -L$(LIB_DIR) 
+#-L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+LDFLAGS		+= -Wl,-Map=$(MAP),--cref -Wl,--gc-sections -Wl,--print-memory-usage
+
+###############################################################################
+# Used libraries
+#LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(CC) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST) $(MAP)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F303-nolib/floatPrintf/hardware.c

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the F303usart project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+#include "usart.h"
+
+static inline void gpio_setup(){
+    RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN; // for USART and LEDs
+    for(int i = 0; i < 10000; ++i) nop();
+    GPIOB->MODER = GPIO_MODER_MODER0_O | GPIO_MODER_MODER1_O;
+    GPIOB->ODR = 1;
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+

F303-nolib/floatPrintf/hardware.h

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the F303usart project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f3.h"
+
+void hw_setup();
+
+#endif // __HARDWARE_H__

F303-nolib/floatPrintf/main.c

@@ -0,0 +1,163 @@
+/*
+ * This file is part of the F303usart project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "stm32f3.h"
+#include "hardware.h"
+#include "usart.h"
+
+//#include <arm_math.h>
+
+volatile uint32_t Tms = 0;
+
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+# define IEEE_754_FLOAT_MANTISSA_BITS (23)
+# define IEEE_754_FLOAT_EXPONENT_BITS (8)
+# define IEEE_754_FLOAT_SIGN_BITS     (1)
+# if (IS_BIG_ENDIAN == 1)
+    typedef union {
+        float value;
+        struct {
+            __int8_t   sign     : IEEE_754_FLOAT_SIGN_BITS;
+            __int8_t   exponent : IEEE_754_FLOAT_EXPONENT_BITS;
+            __uint32_t mantissa : IEEE_754_FLOAT_MANTISSA_BITS;
+        };
+    } IEEE_754_float;
+# else
+    typedef union {
+        float value;
+        struct {
+            __uint32_t mantissa : IEEE_754_FLOAT_MANTISSA_BITS;
+            __int8_t   exponent : IEEE_754_FLOAT_EXPONENT_BITS;
+            __int8_t   sign     : IEEE_754_FLOAT_SIGN_BITS;
+        };
+    } IEEE_754_float;
+# endif
+
+
+#define P(x)  usart_putchar(x)
+#define S(x) usart_send(x)
+
+// be careful: if pow10 would be bigger you should change str[] size!
+static const float pwr10[] = {1., 10., 100., 1000., 10000.};
+static const float rounds[] = {0.5, 0.05, 0.005, 0.0005, 0.00005};
+#define P10L  (sizeof(pwr10)/sizeof(uint32_t) - 1)
+static char * float2str(float x, uint8_t prec){
+    if(prec > P10L) prec = P10L;
+    static char str[16] = {0}; // -117.5494E-36\0 - 14 symbols max!
+    char *s = str + 14; // go to end of buffer
+    uint8_t minus = 0;
+    if(x < 0){
+        x = -x;
+        minus = 1;
+    }
+    int pow = 0; // xxxEpow
+    // now convert float to 1.xxxE3y
+    while(x > 1000.f){
+        x /= 1000.f;
+        pow += 3;
+    }
+    while(x < 1.){
+        x *= 1000.f;
+        pow -= 3;
+    }
+    // print Eyy
+    if(pow){
+        uint8_t m = 0;
+        if(pow < 0){pow = -pow; m = 1;}
+        while(pow){
+            register int p10 = pow/10;
+            *s-- = '0' + (pow - 10*p10);
+            pow = p10;
+        }
+        if(m) *s-- = '-';
+        *s-- = 'E';
+    }
+    // now our number is in [1, 1000]
+    uint32_t units;
+    if(prec){
+        units = (uint32_t) x;
+        uint32_t decimals = (uint32_t)((x-units+rounds[prec])*pwr10[prec]);
+        // print decimals
+        while(prec){
+            register int d10 = decimals / 10;
+            *s-- = '0' + (decimals - 10*d10);
+            decimals = d10;
+            --prec;
+        }
+        // decimal point
+        *s-- = '.';
+    }else{ // without decimal part
+        units = (uint32_t) (x + 0.5);
+    }
+    // print main units
+    if(units == 0) *s-- = '0';
+    else while(units){
+        register uint32_t u10 = units / 10;
+        *s-- = '0' + (units - 10*u10);
+        units = u10;
+    }
+    if(minus) *s-- = '-';
+    return s+1;
+}
+
+static const float tests[] = {-1.23456789e-37, -3.14159265e-2, -1234.56789, -1.2345678, 0.1234567, 123.456789, 1.98765e7, 2.473829e31};
+#define TESTN 8
+
+int main(void){
+    sysreset();
+    if(!StartHSE()) StartHSI();
+    SysTick_Config((uint32_t)72000); // 1ms
+    hw_setup();
+    usart_setup();
+    usart_send("Start\n");
+    uint32_t ctr = Tms;
+    float x = 0.519, more = 5.123;
+    while(1){
+        if(Tms - ctr > 499){
+            //usart_send("ping\n");
+            ctr = Tms;
+            pin_toggle(GPIOB, 1 << 1 | 1 << 0); // toggle LED @ PB0
+            /**/
+            if((x += 0.519) > more){
+                //usart_send("MORE!\n");
+                more += 5.123;
+                //__get_FPSCR();
+            }
+        }
+        if(bufovr){
+            bufovr = 0;
+            usart_send("bufovr\n");
+        }
+        char *txt = NULL;
+        if(usart_getline(&txt)){
+            if(*txt == '?'){
+                for(int i = 0; i < TESTN; ++i) for(int j = 0; j <= (int)P10L; ++j){
+                    usart_send(float2str(tests[i], j));
+                    usart_putchar('\n');
+                }
+            }else{
+                usart_send("Get by USART1: ");
+                usart_send(txt);
+                usart_putchar('\n');
+            }
+        }
+    }
+}

F303-nolib/floatPrintf/usart.c

@@ -0,0 +1,106 @@
+/*
+ * This file is part of the F303usart project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "stm32f3.h"
+#include "hardware.h"
+#include "usart.h"
+#include <string.h>
+
+static volatile int idatalen = 0; // received data line length (including '\n')
+
+volatile int linerdy = 0,   // received data ready
+    dlen    = 0,            // length of data (including '\n') in current buffer
+    bufovr  = 0;            // input buffer overfull
+
+static volatile int rbufno = 0; // current rbuf number
+static char rbuf[2][UARTBUFSZ]; // receive buffers
+static volatile char *recvdata = NULL;
+
+/**
+ * return length of received data (without trailing zero)
+ */
+int usart_getline(char **line){
+    if(bufovr){
+        bufovr = 0;
+        linerdy = 0;
+        return 0;
+    }
+    if(!linerdy) return 0;
+    *line = (char*)recvdata;
+    linerdy = 0;
+    return dlen;
+}
+
+void usart_putchar(const char ch){
+    while(!(USART1->ISR & USART_ISR_TXE));
+    USART1->TDR = ch;
+}
+void usart_sendn(const char *str, int L){
+    if(!str) return;
+    for(int i = 0; i < L; ++i){
+        usart_putchar(str[i]);
+    }
+}
+void usart_send(const char *str){
+    if(!str) return;
+    int L = 0;
+    const char *ptr = str;
+    while(*ptr++) ++L;
+    usart_sendn(str, L);
+}
+
+void usart_setup(){
+    // USART1: Rx - PA10 (AF7), Tx - PA9  (AF7)
+    // setup pins:
+    GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9 | GPIO_MODER_MODER10)) |
+                   GPIO_MODER_MODER9_AF | GPIO_MODER_MODER10_AF;
+    GPIOA->AFR[1] = (GPIOA->AFR[1] & ~(GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2)) |
+                7 << (1 * 4) | 7 << (2 * 4); // PA9, PA10
+    // clock
+    RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
+    USART1->ICR = 0xffffffff; // clear all flags
+    USART1->BRR = 720000 / 1152;
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE | USART_CR1_RXNEIE; // 1start,8data,nstop; enable Rx,Tx,USART
+    uint32_t tmout = 16000000;
+    while(!(USART1->ISR & USART_ISR_TC)){if(--tmout == 0) break;} // polling idle frame Transmission
+    USART1->ICR = 0xffffffff; // clear all flags again
+    NVIC_SetPriority(USART1_IRQn, 0);
+    NVIC_EnableIRQ(USART1_IRQn);
+}
+
+void usart1_exti25_isr(){
+    if(USART1->ISR & USART_ISR_RXNE){ // RX not emty - receive next char
+        // read RDR clears flag
+        uint8_t rb = USART1->RDR;
+        if(idatalen < UARTBUFSZ){ // put next char into buf
+            rbuf[rbufno][idatalen++] = rb;
+            if(rb == '\n'){ // got newline - line ready
+                linerdy = 1;
+                dlen = idatalen;
+                recvdata = rbuf[rbufno];
+                recvdata[dlen-1] = 0;
+                // prepare other buffer
+                rbufno = !rbufno;
+                idatalen = 0;
+            }
+        }else{ // buffer overrun
+            bufovr = 1;
+            idatalen = 0;
+        }
+    }
+}

F303-nolib/floatPrintf/usart.h

@@ -0,0 +1,36 @@
+/*
+ * This file is part of the F303usart project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USART_H__
+#define __USART_H__
+
+#include "hardware.h"
+
+// input buffers size
+#define UARTBUFSZ  (80)
+
+extern volatile int linerdy, bufovr;
+
+void usart_setup();
+int usart_getline(char **line);
+void usart_send(const char *str);
+void usart_sendn(const char *str, int L);
+void usart_putchar(const char ch);
+
+#endif // __USART_H__

F303-nolib/inc/Fx/stm32f3.h

@@ -32,6 +32,10 @@
 
 #define VECT_TAB_OFFSET  0x0 /*!< Vector Table base offset field.
                                   This value must be a multiple of 0x200. */
+/*
+TRUE_INLINE void enable_FPU(){
+    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  // set CP10 and CP11 Full Access
+}*/
 
 //extern uint32_t SystemCoreClock;          /*!< System Clock Frequency (Core Clock) */
 //extern const uint8_t AHBPrescTable[16];   /*!< AHB prescalers table values */
@@ -45,11 +49,6 @@
   */
 TRUE_INLINE void sysreset(void) // not usable
 {
-  /* FPU settings ------------------------------------------------------------*/
-  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
-    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */
-  #endif
-
   /* Reset the RCC clock configuration to the default reset state ------------*/
   /* Set HSION bit */
   RCC->CR |= RCC_CR_HSION;

F303-nolib/inc/startup/vector.c

@@ -833,6 +833,14 @@ void WEAK __attribute__ ((naked)) __attribute__ ((noreturn)) reset_handler(void)
   // enable 8-byte stack alignment to comply with AAPCS
   SCB->CCR |= 0x00000200;
 
+  /* FPU settings ------------------------------------------------------------*/
+  #if (__FPU_PRESENT == 1)
+    SCB->CPACR = 0x0f << 20 ;  /* set CP10 and CP11 Full Access */
+    nop();
+    __DSB();
+    __ISB();
+  #endif
+
   // copy initialized variables data
   while ( dst < &_edata ) { *dst++ = *src++; }