aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPiotr Esden-Tempski2012-10-05 13:03:58 -0700
committerPiotr Esden-Tempski2012-10-05 13:03:58 -0700
commitcb60e3760867133bbef90905c681881a2fb3ae50 (patch)
treea971d20e9ec8986f6857b951d036f70e104f0463
parent4efa64c2785692b422988f7444e737c67931ea5d (diff)
parentaac5909ff133a71dc01037712f86e89f4e7877d7 (diff)
Merging pull request #37 Adds hard-float support to stm32f4, with a nice mandelbrot example
Merge remote-tracking branch 'schodet/hard-float'
-rw-r--r--examples/stm32/f4/Makefile.include5
-rw-r--r--examples/stm32/f4/stm32f4-discovery/mandelbrot/Makefile25
-rw-r--r--examples/stm32/f4/stm32f4-discovery/mandelbrot/README12
-rw-r--r--examples/stm32/f4/stm32f4-discovery/mandelbrot/mandel.c127
-rw-r--r--include/libopencm3/stm32/f4/scb.h69
-rw-r--r--lib/stm32/f4/Makefile3
-rw-r--r--lib/stm32/f4/vector.c5
7 files changed, 243 insertions, 3 deletions
diff --git a/examples/stm32/f4/Makefile.include b/examples/stm32/f4/Makefile.include
index 8fa9391..f436bc8 100644
--- a/examples/stm32/f4/Makefile.include
+++ b/examples/stm32/f4/Makefile.include
@@ -36,12 +36,13 @@ endif
TOOLCHAIN_DIR := ../../../../..
endif
CFLAGS += -Os -g -Wall -Wextra -I$(TOOLCHAIN_DIR)/include \
- -fno-common -mcpu=cortex-m4 -mthumb -msoft-float -MD -DSTM32F4
+ -fno-common -mcpu=cortex-m4 -mthumb \
+ -mfloat-abi=hard -mfpu=fpv4-sp-d16 -MD -DSTM32F4
LDSCRIPT ?= $(BINARY).ld
LDFLAGS += --static -lc -lnosys -L$(TOOLCHAIN_DIR)/lib \
-L$(TOOLCHAIN_DIR)/lib/stm32/f4 \
-T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections \
- -mthumb -mcpu=cortex-m4 -march=armv7 -mfix-cortex-m3-ldrd -msoft-float
+ -mthumb -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16
OBJS += $(BINARY).o
OOCD ?= openocd
diff --git a/examples/stm32/f4/stm32f4-discovery/mandelbrot/Makefile b/examples/stm32/f4/stm32f4-discovery/mandelbrot/Makefile
new file mode 100644
index 0000000..3879eca
--- /dev/null
+++ b/examples/stm32/f4/stm32f4-discovery/mandelbrot/Makefile
@@ -0,0 +1,25 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library 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 Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library. If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = mandel
+
+LDSCRIPT = ../stm32f4-discovery.ld
+
+include ../../Makefile.include
+
diff --git a/examples/stm32/f4/stm32f4-discovery/mandelbrot/README b/examples/stm32/f4/stm32f4-discovery/mandelbrot/README
new file mode 100644
index 0000000..fe4fb13
--- /dev/null
+++ b/examples/stm32/f4/stm32f4-discovery/mandelbrot/README
@@ -0,0 +1,12 @@
+------------------------------------------------------------------------------
+README
+------------------------------------------------------------------------------
+
+This example program demonstrates the floating point coprocessor usage on
+the ST STM32F4DISCOVERY eval board.
+
+A mandelbrot fractal is calculated and sent as "ascii-art" image through
+the USART2.
+
+The terminal settings for the receiving device/PC are 38400 8n1.
+
diff --git a/examples/stm32/f4/stm32f4-discovery/mandelbrot/mandel.c b/examples/stm32/f4/stm32f4-discovery/mandelbrot/mandel.c
new file mode 100644
index 0000000..5cbdafd
--- /dev/null
+++ b/examples/stm32/f4/stm32f4-discovery/mandelbrot/mandel.c
@@ -0,0 +1,127 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
+ * Copyright (C) 2012 Daniel Serpell <daniel.serpell@gmail.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/f4/rcc.h>
+#include <libopencm3/stm32/f4/gpio.h>
+#include <libopencm3/stm32/usart.h>
+
+void clock_setup(void)
+{
+ /* Enable high-speed clock at 120MHz */
+ rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_120MHZ]);
+
+ /* Enable GPIOD clock for LED & USARTs. */
+ rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);
+ rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);
+
+ /* Enable clocks for USART2. */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+}
+
+void usart_setup(void)
+{
+ /* Setup USART2 parameters. */
+ usart_set_baudrate(USART2, 38400);
+ usart_set_databits(USART2, 8);
+ usart_set_stopbits(USART2, USART_STOPBITS_1);
+ usart_set_mode(USART2, USART_MODE_TX);
+ usart_set_parity(USART2, USART_PARITY_NONE);
+ usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
+
+ /* Finally enable the USART. */
+ usart_enable(USART2);
+}
+
+void gpio_setup(void)
+{
+ /* Setup GPIO pin GPIO12 on GPIO port D for LED. */
+ gpio_mode_setup(GPIOD, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO12);
+
+ /* Setup GPIO pins for USART2 transmit. */
+ gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
+
+ /* Setup USART2 TX pin as alternate function. */
+ gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
+}
+
+/* Maximum number of iterations for the escape-time calculation */
+#define maxIter 32
+/* This array converts the iteration count to a character representation. */
+static char color[maxIter+1] = " .:++xxXXX%%%%%%################";
+
+/* Main mandelbrot calculation */
+static int iterate(float px, float py)
+{
+ int it=0;
+ float x=0,y=0;
+ while(it<maxIter)
+ {
+ float nx = x*x;
+ float ny = y*y;
+ if( (nx + ny) > 4 )
+ return it;
+ // Zn+1 = Zn^2 + P
+ y = 2*x*y + py;
+ x = nx - ny + px;
+ it++;
+ }
+ return 0;
+}
+
+static void mandel(float cX, float cY, float scale)
+{
+ int x,y;
+ for(x=-60;x<60;x++)
+ {
+ for(y=-50;y<50;y++)
+ {
+ int i = iterate(cX+x*scale, cY+y*scale);
+ usart_send_blocking(USART2, color[i]);
+ }
+ usart_send_blocking(USART2, '\r');
+ usart_send_blocking(USART2, '\n');
+ }
+}
+
+int main(void)
+{
+ float scale = 0.25f, centerX = -0.5f, centerY = 0.0f;
+
+ clock_setup();
+ gpio_setup();
+ usart_setup();
+
+ while (1) {
+ /* Blink the LED (PD12) on the board with each fractal drawn. */
+ gpio_toggle(GPIOD, GPIO12); /* LED on/off */
+ mandel(centerX,centerY,scale); /* draw mandelbrot */
+
+ /* Change scale and center */
+ centerX += 0.175f * scale;
+ centerY += 0.522f * scale;
+ scale *= 0.875f;
+
+ usart_send_blocking(USART2, '\r');
+ usart_send_blocking(USART2, '\n');
+ }
+
+ return 0;
+}
diff --git a/include/libopencm3/stm32/f4/scb.h b/include/libopencm3/stm32/f4/scb.h
index 181aa7a..7187ca9 100644
--- a/include/libopencm3/stm32/f4/scb.h
+++ b/include/libopencm3/stm32/f4/scb.h
@@ -72,6 +72,63 @@
/* AFSR: Auxiliary Fault Status Register */
#define SCB_AFSR MMIO32(SCB_BASE + 0x3C)
+/* ID_PFR0: Processor Feature Register 0 */
+#define SCB_ID_PFR0 MMIO32(SCB_BASE + 0x40)
+
+/* ID_PFR1: Processor Feature Register 1 */
+#define SCB_ID_PFR1 MMIO32(SCB_BASE + 0x44)
+
+/* ID_DFR0: Debug Features Register 0 */
+#define SCB_ID_DFR0 MMIO32(SCB_BASE + 0x48)
+
+/* ID_AFR0: Auxiliary Features Register 0 */
+#define SCB_ID_AFR0 MMIO32(SCB_BASE + 0x4C)
+
+/* ID_MMFR0: Memory Model Feature Register 0 */
+#define SCB_ID_MMFR0 MMIO32(SCB_BASE + 0x50)
+
+/* ID_MMFR1: Memory Model Feature Register 1 */
+#define SCB_ID_MMFR1 MMIO32(SCB_BASE + 0x54)
+
+/* ID_MMFR2: Memory Model Feature Register 2 */
+#define SCB_ID_MMFR2 MMIO32(SCB_BASE + 0x58)
+
+/* ID_MMFR3: Memory Model Feature Register 3 */
+#define SCB_ID_MMFR3 MMIO32(SCB_BASE + 0x5C)
+
+/* ID_ISAR0: Instruction Set Attributes Register 0 */
+#define SCB_ID_ISAR0 MMIO32(SCB_BASE + 0x60)
+
+/* ID_ISAR1: Instruction Set Attributes Register 1 */
+#define SCB_ID_ISAR1 MMIO32(SCB_BASE + 0x64)
+
+/* ID_ISAR2: Instruction Set Attributes Register 2 */
+#define SCB_ID_ISAR2 MMIO32(SCB_BASE + 0x68)
+
+/* ID_ISAR3: Instruction Set Attributes Register 3 */
+#define SCB_ID_ISAR3 MMIO32(SCB_BASE + 0x6C)
+
+/* ID_ISAR4: Instruction Set Attributes Register 4 */
+#define SCB_ID_ISAR4 MMIO32(SCB_BASE + 0x70)
+
+/* CPACR: Coprocessor Access Control Register */
+#define SCB_CPACR MMIO32(SCB_BASE + 0x88)
+
+/* FPCCR: Floating-Point Context Control Register */
+#define SCB_FPCCR MMIO32(SCB_BASE + 0x234)
+
+/* FPCAR: Floating-Point Context Address Register */
+#define SCB_FPCAR MMIO32(SCB_BASE + 0x238)
+
+/* FPDSCR: Floating-Point Default Status Control Register */
+#define SCB_FPDSCR MMIO32(SCB_BASE + 0x23C)
+
+/* MVFR0: Media and Floating-Point Feature Register 0 */
+#define SCB_MVFR0 MMIO32(SCB_BASE + 0x240)
+
+/* MVFR1: Media and Floating-Point Feature Register 1 */
+#define SCB_MVFR1 MMIO32(SCB_BASE + 0x244)
+
/* --- SCB values ---------------------------------------------------------- */
/* --- SCB_CPUID values ---------------------------------------------------- */
@@ -292,6 +349,18 @@
/* BFAR [31:0]: Bus fault address */
+/* --- SCB_CPACR values ---------------------------------------------------- */
+
+/* CPACR CPn: Access privileges values */
+#define SCB_CPACR_NONE 0 /* Access denied */
+#define SCB_CPACR_PRIV 1 /* Privileged access only */
+#define SCB_CPACR_FULL 3 /* Full access */
+
+/* CPACR [20:21]: Access privileges for coprocessor 10 */
+#define SCB_CPACR_CP10 (1 << 20)
+/* CPACR [22:23]: Access privileges for coprocessor 11 */
+#define SCB_CPACR_CP11 (1 << 22)
+
/* --- SCB functions ------------------------------------------------------- */
BEGIN_DECLS
diff --git a/lib/stm32/f4/Makefile b/lib/stm32/f4/Makefile
index 85870a7..fd0b279 100644
--- a/lib/stm32/f4/Makefile
+++ b/lib/stm32/f4/Makefile
@@ -24,7 +24,8 @@ PREFIX ?= arm-none-eabi
CC = $(PREFIX)-gcc
AR = $(PREFIX)-ar
CFLAGS = -Os -g -Wall -Wextra -I../../../include -fno-common \
- -mcpu=cortex-m3 -mthumb -Wstrict-prototypes \
+ -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 \
+ -Wstrict-prototypes \
-ffunction-sections -fdata-sections -MD -DSTM32F4
# ARFLAGS = rcsv
ARFLAGS = rcs
diff --git a/lib/stm32/f4/vector.c b/lib/stm32/f4/vector.c
index 3429bfb..01b5e64 100644
--- a/lib/stm32/f4/vector.c
+++ b/lib/stm32/f4/vector.c
@@ -18,6 +18,8 @@
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <libopencm3/stm32/f4/scb.h>
+
#define WEAK __attribute__ ((weak))
/* Symbols exported by the linker script(s): */
@@ -224,6 +226,9 @@ void reset_handler(void)
__asm__("MSR msp, %0" : : "r"(&_stack));
+ /* Enable access to Floating-Point coprocessor. */
+ SCB_CPACR |= SCB_CPACR_FULL * (SCB_CPACR_CP10 | SCB_CPACR_CP11);
+
for (src = &_data_loadaddr, dest = &_data; dest < &_edata; src++, dest++)
*dest = *src;