initial FW setup for Raven validation

hello/hello.c

@@ -57,12 +57,6 @@ unsigned read_adc(unsigned index){
     return result&0x03ff;
 }
 
-//int read_csr(int csr_num) __attribute__((always_inline)) {
-//    int result;
-//    asm("csrr %0, %1" : "=r"(result) : "I"(csr_num));
-//    return result;
-//}
-
 int main()
 {
 	GPIO_REG(GPIO_IOF_EN) |= 0x30000;

raven/Makefile

@@ -0,0 +1,13 @@
+
+TARGET = hello_raven
+C_SRCS += $(wildcard *.c) 
+CFLAGS += -g 
+#-fno-builtin-printf
+LDFLAGS := -Wl,--wrap=scanf -Wl,--wrap=printf 
+
+#BOARD = iss
+BOARD=freedom-e300-hifive1
+TOOL_DIR=/opt/shared/riscv/FreedomStudio/20180122/SiFive/riscv64-unknown-elf-gcc-20171231-x86_64-linux-centos6/bin
+
+BSP_BASE = ./bsp
+include $(BSP_BASE)/env/common.mk

raven/bsp/Debug/drivers/fe300prci/subdir.mk

@@ -0,0 +1,24 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../drivers/fe300prci/fe300prci_driver.c 
+
+OBJS += \
+./drivers/fe300prci/fe300prci_driver.o 
+
+C_DEPS += \
+./drivers/fe300prci/fe300prci_driver.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+drivers/fe300prci/%.o: ../drivers/fe300prci/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/drivers/plic/subdir.mk

@@ -0,0 +1,24 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../drivers/plic/plic_driver.c 
+
+OBJS += \
+./drivers/plic/plic_driver.o 
+
+C_DEPS += \
+./drivers/plic/plic_driver.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+drivers/plic/%.o: ../drivers/plic/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/env/freedom-e300-arty/subdir.mk

@@ -0,0 +1,24 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../env/freedom-e300-arty/init.c 
+
+OBJS += \
+./env/freedom-e300-arty/init.o 
+
+C_DEPS += \
+./env/freedom-e300-arty/init.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+env/freedom-e300-arty/%.o: ../env/freedom-e300-arty/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/env/freedom-e300-hifive1/subdir.mk

@@ -0,0 +1,27 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../env/freedom-e300-hifive1/init.c 
+
+O_SRCS += \
+../env/freedom-e300-hifive1/init.o 
+
+OBJS += \
+./env/freedom-e300-hifive1/init.o 
+
+C_DEPS += \
+./env/freedom-e300-hifive1/init.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+env/freedom-e300-hifive1/%.o: ../env/freedom-e300-hifive1/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/env/iss/subdir.mk

@@ -0,0 +1,27 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../env/iss/init.c 
+
+O_SRCS += \
+../env/iss/init.o 
+
+OBJS += \
+./env/iss/init.o 
+
+C_DEPS += \
+./env/iss/init.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+env/iss/%.o: ../env/iss/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/env/subdir.mk

@@ -0,0 +1,27 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+O_SRCS += \
+../env/entry.o \
+../env/start.o 
+
+S_UPPER_SRCS += \
+../env/entry.S \
+../env/start.S 
+
+OBJS += \
+./env/entry.o \
+./env/start.o 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+env/%.o: ../env/%.S
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Assembler'
+	riscv32-unknown-elf-as  -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/libwrap/stdlib/subdir.mk

@@ -0,0 +1,27 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../libwrap/stdlib/malloc.c 
+
+O_SRCS += \
+../libwrap/stdlib/malloc.o 
+
+OBJS += \
+./libwrap/stdlib/malloc.o 
+
+C_DEPS += \
+./libwrap/stdlib/malloc.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+libwrap/stdlib/%.o: ../libwrap/stdlib/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/libwrap/sys/subdir.mk

@@ -0,0 +1,98 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+# Add inputs and outputs from these tool invocations to the build variables 
+C_SRCS += \
+../libwrap/sys/_exit.c \
+../libwrap/sys/close.c \
+../libwrap/sys/execve.c \
+../libwrap/sys/fork.c \
+../libwrap/sys/fstat.c \
+../libwrap/sys/getpid.c \
+../libwrap/sys/isatty.c \
+../libwrap/sys/kill.c \
+../libwrap/sys/link.c \
+../libwrap/sys/lseek.c \
+../libwrap/sys/open.c \
+../libwrap/sys/openat.c \
+../libwrap/sys/read.c \
+../libwrap/sys/sbrk.c \
+../libwrap/sys/stat.c \
+../libwrap/sys/times.c \
+../libwrap/sys/unlink.c \
+../libwrap/sys/wait.c \
+../libwrap/sys/write.c 
+
+O_SRCS += \
+../libwrap/sys/_exit.o \
+../libwrap/sys/close.o \
+../libwrap/sys/execve.o \
+../libwrap/sys/fork.o \
+../libwrap/sys/fstat.o \
+../libwrap/sys/getpid.o \
+../libwrap/sys/isatty.o \
+../libwrap/sys/kill.o \
+../libwrap/sys/link.o \
+../libwrap/sys/lseek.o \
+../libwrap/sys/open.o \
+../libwrap/sys/read.o \
+../libwrap/sys/sbrk.o \
+../libwrap/sys/stat.o \
+../libwrap/sys/times.o \
+../libwrap/sys/unlink.o \
+../libwrap/sys/wait.o \
+../libwrap/sys/write.o 
+
+OBJS += \
+./libwrap/sys/_exit.o \
+./libwrap/sys/close.o \
+./libwrap/sys/execve.o \
+./libwrap/sys/fork.o \
+./libwrap/sys/fstat.o \
+./libwrap/sys/getpid.o \
+./libwrap/sys/isatty.o \
+./libwrap/sys/kill.o \
+./libwrap/sys/link.o \
+./libwrap/sys/lseek.o \
+./libwrap/sys/open.o \
+./libwrap/sys/openat.o \
+./libwrap/sys/read.o \
+./libwrap/sys/sbrk.o \
+./libwrap/sys/stat.o \
+./libwrap/sys/times.o \
+./libwrap/sys/unlink.o \
+./libwrap/sys/wait.o \
+./libwrap/sys/write.o 
+
+C_DEPS += \
+./libwrap/sys/_exit.d \
+./libwrap/sys/close.d \
+./libwrap/sys/execve.d \
+./libwrap/sys/fork.d \
+./libwrap/sys/fstat.d \
+./libwrap/sys/getpid.d \
+./libwrap/sys/isatty.d \
+./libwrap/sys/kill.d \
+./libwrap/sys/link.d \
+./libwrap/sys/lseek.d \
+./libwrap/sys/open.d \
+./libwrap/sys/openat.d \
+./libwrap/sys/read.d \
+./libwrap/sys/sbrk.d \
+./libwrap/sys/stat.d \
+./libwrap/sys/times.d \
+./libwrap/sys/unlink.d \
+./libwrap/sys/wait.d \
+./libwrap/sys/write.d 
+
+
+# Each subdirectory must supply rules for building sources it contributes
+libwrap/sys/%.o: ../libwrap/sys/%.c
+	@echo 'Building file: $<'
+	@echo 'Invoking: Cross GCC Compiler'
+	riscv32-unknown-elf-gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@)" -o "$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+

raven/bsp/Debug/makefile

@@ -0,0 +1,66 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+-include ../makefile.init
+
+RM := rm -rf
+
+# All of the sources participating in the build are defined here
+-include sources.mk
+-include libwrap/sys/subdir.mk
+-include libwrap/stdlib/subdir.mk
+-include libwrap/misc/subdir.mk
+-include env/iss/subdir.mk
+-include env/freedom-e300-hifive1/subdir.mk
+-include env/freedom-e300-arty/subdir.mk
+-include env/subdir.mk
+-include drivers/plic/subdir.mk
+-include drivers/fe300prci/subdir.mk
+-include subdir.mk
+-include objects.mk
+
+ifneq ($(MAKECMDGOALS),clean)
+ifneq ($(strip $(CC_DEPS)),)
+-include $(CC_DEPS)
+endif
+ifneq ($(strip $(C++_DEPS)),)
+-include $(C++_DEPS)
+endif
+ifneq ($(strip $(C_UPPER_DEPS)),)
+-include $(C_UPPER_DEPS)
+endif
+ifneq ($(strip $(CXX_DEPS)),)
+-include $(CXX_DEPS)
+endif
+ifneq ($(strip $(C_DEPS)),)
+-include $(C_DEPS)
+endif
+ifneq ($(strip $(CPP_DEPS)),)
+-include $(CPP_DEPS)
+endif
+endif
+
+-include ../makefile.defs
+
+# Add inputs and outputs from these tool invocations to the build variables 
+
+# All Target
+all: bsp
+
+# Tool invocations
+bsp: $(OBJS) $(USER_OBJS)
+	@echo 'Building target: $@'
+	@echo 'Invoking: Cross G++ Linker'
+	riscv32-unknown-elf-g++  -o "bsp" $(OBJS) $(USER_OBJS) $(LIBS)
+	@echo 'Finished building target: $@'
+	@echo ' '
+
+# Other Targets
+clean:
+	-$(RM) $(CC_DEPS)$(C++_DEPS)$(EXECUTABLES)$(OBJS)$(C_UPPER_DEPS)$(CXX_DEPS)$(C_DEPS)$(CPP_DEPS) bsp
+	-@echo ' '
+
+.PHONY: all clean dependents
+
+-include ../makefile.targets

raven/bsp/Debug/objects.mk

@@ -0,0 +1,8 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+USER_OBJS :=
+
+LIBS :=
+

raven/bsp/Debug/sources.mk

@@ -0,0 +1,35 @@
+################################################################################
+# Automatically-generated file. Do not edit!
+################################################################################
+
+C_UPPER_SRCS := 
+CXX_SRCS := 
+C++_SRCS := 
+OBJ_SRCS := 
+CC_SRCS := 
+ASM_SRCS := 
+C_SRCS := 
+CPP_SRCS := 
+O_SRCS := 
+S_UPPER_SRCS := 
+CC_DEPS := 
+C++_DEPS := 
+EXECUTABLES := 
+OBJS := 
+C_UPPER_DEPS := 
+CXX_DEPS := 
+C_DEPS := 
+CPP_DEPS := 
+
+# Every subdirectory with source files must be described here
+SUBDIRS := \
+drivers/fe300prci \
+drivers/plic \
+env \
+env/freedom-e300-arty \
+env/freedom-e300-hifive1 \
+env/iss \
+libwrap/misc \
+libwrap/stdlib \
+libwrap/sys \
+

raven/bsp/drivers/fe300prci/fe300prci_driver.c

@@ -0,0 +1,252 @@
+// See LICENSE file for license details
+
+#include "platform.h"
+
+#ifdef PRCI_BASE_ADDR
+#include "fe300prci/fe300prci_driver.h"
+#include <unistd.h>
+
+#define rdmcycle(x)  {				       \
+    uint32_t lo, hi, hi2;			       \
+    __asm__ __volatile__ ("1:\n\t"		       \
+			  "csrr %0, mcycleh\n\t"       \
+			  "csrr %1, mcycle\n\t"	       \
+			  "csrr %2, mcycleh\n\t"		\
+			  "bne  %0, %2, 1b\n\t"			\
+			  : "=r" (hi), "=r" (lo), "=r" (hi2)) ;	\
+    *(x) = lo | ((uint64_t) hi << 32); 				\
+  }
+
+uint32_t PRCI_measure_mcycle_freq(uint32_t mtime_ticks, uint32_t mtime_freq)
+{
+
+  uint32_t start_mtime = CLINT_REG(CLINT_MTIME);
+  uint32_t end_mtime = start_mtime + mtime_ticks + 1;
+
+  // Make sure we won't get rollover.
+  while (end_mtime < start_mtime){
+    start_mtime = CLINT_REG(CLINT_MTIME);
+    end_mtime = start_mtime + mtime_ticks + 1;
+  }
+
+  // Don't start measuring until mtime edge.
+  uint32_t tmp = start_mtime;
+  do {
+    start_mtime = CLINT_REG(CLINT_MTIME);
+  } while (start_mtime == tmp);
+  
+  uint64_t start_mcycle;
+  rdmcycle(&start_mcycle);
+  
+  while (CLINT_REG(CLINT_MTIME) < end_mtime) ;
+  
+  uint64_t end_mcycle;
+  rdmcycle(&end_mcycle);
+  uint32_t difference = (uint32_t) (end_mcycle - start_mcycle);
+
+  uint64_t freq = ((uint64_t) difference * mtime_freq) / mtime_ticks;
+  return (uint32_t) freq & 0xFFFFFFFF;
+  
+}
+ 
+
+void PRCI_use_hfrosc(int div, int trim)
+{
+  // Make sure the HFROSC is running at its default setting
+  // It is OK to change this even if we are running off of it.
+  
+  PRCI_REG(PRCI_HFROSCCFG) = (ROSC_DIV(div) | ROSC_TRIM(trim) | ROSC_EN(1));
+
+  while ((PRCI_REG(PRCI_HFROSCCFG) & ROSC_RDY(1)) == 0);
+  
+  PRCI_REG(PRCI_PLLCFG) &= ~PLL_SEL(1);
+}
+
+void PRCI_use_pll(int refsel, int bypass,
+			 int r, int f, int q, int finaldiv,
+			 int hfroscdiv, int hfrosctrim)
+{
+  // Ensure that we aren't running off the PLL before we mess with it.
+  if (PRCI_REG(PRCI_PLLCFG) & PLL_SEL(1)) {
+    // Make sure the HFROSC is running at its default setting
+    PRCI_use_hfrosc(4, 16);
+  }
+  
+  // Set PLL Source to be HFXOSC if desired.
+  uint32_t config_value = 0;
+
+  config_value |= PLL_REFSEL(refsel);
+  
+  if (bypass) {
+    // Bypass
+    config_value |= PLL_BYPASS(1);
+
+    PRCI_REG(PRCI_PLLCFG) = config_value;
+
+    // If we don't have an HFXTAL, this doesn't really matter.
+    // Set our Final output divide to divide-by-1:
+    PRCI_REG(PRCI_PLLDIV) = (PLL_FINAL_DIV_BY_1(1) | PLL_FINAL_DIV(0));
+  } else {
+  
+    // To overclock, use the hfrosc
+    if (hfrosctrim >= 0 && hfroscdiv >= 0) {
+      PRCI_use_hfrosc(hfroscdiv, hfrosctrim);
+    }
+    
+    // Set DIV Settings for PLL
+    
+    // (Legal values of f_REF are 6-48MHz)
+
+    // Set DIVR to divide-by-2 to get 8MHz frequency
+    // (legal values of f_R are 6-12 MHz)
+
+    config_value |= PLL_BYPASS(1);
+    config_value |= PLL_R(r);
+
+    // Set DIVF to get 512Mhz frequncy
+    // There is an implied multiply-by-2, 16Mhz.
+    // So need to write 32-1
+    // (legal values of f_F are 384-768 MHz)
+    config_value |= PLL_F(f);
+
+    // Set DIVQ to divide-by-2 to get 256 MHz frequency
+    // (legal values of f_Q are 50-400Mhz)
+    config_value |= PLL_Q(q);
+
+    // Set our Final output divide to divide-by-1:
+    if (finaldiv == 1){
+      PRCI_REG(PRCI_PLLDIV) = (PLL_FINAL_DIV_BY_1(1) | PLL_FINAL_DIV(0));
+    } else {
+      PRCI_REG(PRCI_PLLDIV) = (PLL_FINAL_DIV(finaldiv-1));
+    }
+
+    PRCI_REG(PRCI_PLLCFG) = config_value;
+
+    // Un-Bypass the PLL.
+    PRCI_REG(PRCI_PLLCFG) &= ~PLL_BYPASS(1);
+
+    // Wait for PLL Lock
+    // Note that the Lock signal can be glitchy.
+    // Need to wait 100 us
+    // RTC is running at 32kHz.
+    // So wait 4 ticks of RTC.
+    uint32_t now = CLINT_REG(CLINT_MTIME);
+    while (CLINT_REG(CLINT_MTIME) - now < 4) ;
+    
+    // Now it is safe to check for PLL Lock
+    while ((PRCI_REG(PRCI_PLLCFG) & PLL_LOCK(1)) == 0);
+
+  }
+
+  // Switch over to PLL Clock source
+  PRCI_REG(PRCI_PLLCFG) |= PLL_SEL(1);
+
+  // If we're running off HFXOSC, turn off the HFROSC to
+  // save power.
+  if (refsel) {
+    PRCI_REG(PRCI_HFROSCCFG) &= ~ROSC_EN(1);
+  }
+  
+}
+
+void PRCI_use_default_clocks()
+{
+  // Turn off the LFROSC
+  AON_REG(AON_LFROSC) &= ~ROSC_EN(1);
+
+  // Use HFROSC
+  PRCI_use_hfrosc(4, 16);
+}
+
+void PRCI_use_hfxosc(uint32_t finaldiv)
+{
+  
+  PRCI_use_pll(1, // Use HFXTAL
+	       1, // Bypass = 1
+	       0, // PLL settings don't matter
+	       0, // PLL settings don't matter
+	       0, // PLL settings don't matter
+	       finaldiv,
+	       -1,
+	       -1);
+}
+
+// This is a generic function, which
+// doesn't span the entire range of HFROSC settings.
+// It only adjusts the trim, which can span a hundred MHz or so.
+// This function does not check the legality of the PLL settings
+// at all, and it is quite possible to configure invalid PLL settings
+// this way.
+// It returns the actual measured CPU frequency.
+
+uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target )
+{
+
+  uint32_t hfrosctrim = 0;
+  uint32_t hfroscdiv = 4;
+  uint32_t prev_trim = 0;
+
+  // In this function we use PLL settings which
+  // will give us a 32x multiplier from the output
+  // of the HFROSC source to the output of the
+  // PLL. We first measure our HFROSC to get the
+  // right trim, then finally use it as the PLL source.
+  // We should really check here that the f_cpu
+  // requested is something in the limit of the PLL. For
+  // now that is up to the user.
+
+  // This will undershoot for frequencies not divisible by 16.
+  uint32_t desired_hfrosc_freq = (f_cpu/ 16);
+
+  PRCI_use_hfrosc(hfroscdiv, hfrosctrim);
+  
+  // Ignore the first run (for icache reasons)
+  uint32_t cpu_freq = PRCI_measure_mcycle_freq(3000, RTC_FREQ);
+
+  cpu_freq = PRCI_measure_mcycle_freq(3000, RTC_FREQ);
+  uint32_t prev_freq = cpu_freq;
+  
+  while ((cpu_freq < desired_hfrosc_freq) && (hfrosctrim < 0x1F)){
+    prev_trim = hfrosctrim;
+    prev_freq = cpu_freq;
+    hfrosctrim ++;
+    PRCI_use_hfrosc(hfroscdiv, hfrosctrim);
+    cpu_freq = PRCI_measure_mcycle_freq(3000, RTC_FREQ);
+  } 
+
+  // We couldn't go low enough
+  if (prev_freq > desired_hfrosc_freq){
+    PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, prev_trim);
+    cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ);
+    return cpu_freq;
+  }
+  
+  // We couldn't go high enough
+  if (cpu_freq < desired_hfrosc_freq){
+    PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, prev_trim);
+    cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ);
+    return cpu_freq;
+  }
+
+  // Check for over/undershoot
+  switch(target) {
+  case(PRCI_FREQ_CLOSEST):
+    if ((desired_hfrosc_freq - prev_freq) < (cpu_freq - desired_hfrosc_freq)) {
+      PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, prev_trim);
+    } else {
+      PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, hfrosctrim);
+    }
+    break;
+  case(PRCI_FREQ_UNDERSHOOT):
+    PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, prev_trim);
+    break;
+  default:
+    PRCI_use_pll(0, 0, 1, 31, 1, 1, hfroscdiv, hfrosctrim);
+  }
+
+  cpu_freq =  PRCI_measure_mcycle_freq(1000, RTC_FREQ);
+  return cpu_freq;
+
+}
+
+#endif

raven/bsp/drivers/fe300prci/fe300prci_driver.h

@@ -0,0 +1,79 @@
+// See LICENSE file for license details
+
+#ifndef _FE300PRCI_DRIVER_H_
+#define _FE300PRCI_DRIVER_H_
+
+__BEGIN_DECLS
+
+#include <unistd.h>
+
+typedef enum prci_freq_target {
+  
+  PRCI_FREQ_OVERSHOOT,
+  PRCI_FREQ_CLOSEST,
+  PRCI_FREQ_UNDERSHOOT
+
+} PRCI_freq_target;
+
+/* Measure and return the approximate frequency of the 
+ * CPU, as given by measuring the mcycle counter against 
+ * the mtime ticks.
+ */
+uint32_t PRCI_measure_mcycle_freq(uint32_t mtime_ticks, uint32_t mtime_freq);
+
+/* Safely switch over to the HFROSC using the given div
+ * and trim settings.
+ */
+void PRCI_use_hfrosc(int div, int trim);
+
+/* Safely switch over to the 16MHz HFXOSC,
+ * applying the finaldiv clock divider (1 is the lowest
+ * legal value).
+ */
+void PRCI_use_hfxosc(uint32_t finaldiv);
+
+/* Safely switch over to the PLL using the given
+ * settings.
+ * 
+ * Note that not all combinations of the inputs are actually
+ * legal, and this function does not check for their
+ * legality ("safely" means that this function won't turn off
+ * or glitch the clock the CPU is actually running off, but
+ * doesn't protect against you making it too fast or slow.)
+ */
+
+void PRCI_use_pll(int refsel, int bypass,
+			 int r, int f, int q, int finaldiv,
+			 int hfroscdiv, int hfrosctrim);
+
+/* Use the default clocks configured at reset.
+ * This is ~16Mhz HFROSC and turns off the LFROSC
+ * (on the current FE310 Dev Platforms, an external LFROSC is 
+ * used as it is more power efficient).
+ */
+void PRCI_use_default_clocks();
+
+/* This routine will adjust the HFROSC trim
+ * while using HFROSC as the clock source, 
+ * measure the resulting frequency, then
+ * use it as the PLL clock source, 
+ * in an attempt to get over, under, or close to the 
+ * requested frequency. It returns the actual measured 
+ * frequency. 
+ *
+ * Note that the requested frequency must be within the 
+ * range supported by the PLL so not all values are 
+ * achievable with this function, and not all 
+ * are guaranteed to actually work. The PLL
+ * is rated higher than the hardware.
+ * 
+ * There is no check on the desired f_cpu frequency, it
+ * is up to the user to specify something reasonable.
+ */
+
+uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target);
+
+__END_DECLS
+
+#endif
+  

raven/bsp/drivers/plic/plic_driver.c

@@ -0,0 +1,127 @@
+// See LICENSE for license details.
+
+#include "sifive/devices/plic.h"
+#include "plic/plic_driver.h"
+#include "platform.h"
+#include "encoding.h"
+#include <string.h>
+
+
+// Note that there are no assertions or bounds checking on these
+// parameter values.
+
+void volatile_memzero(uint8_t * base, unsigned int size)
+{
+  volatile uint8_t * ptr;
+  for (ptr = base; ptr < (base + size); ptr++){
+    *ptr = 0;
+  }
+}
+
+void PLIC_init (
+                plic_instance_t * this_plic,
+                uintptr_t         base_addr,
+                uint32_t num_sources,
+                uint32_t num_priorities
+                )
+{
+  
+  this_plic->base_addr = base_addr;
+  this_plic->num_sources = num_sources;
+  this_plic->num_priorities = num_priorities;
+  
+  // Disable all interrupts (don't assume that these registers are reset).
+  unsigned long hart_id = read_csr(mhartid);
+  volatile_memzero((uint8_t*) (this_plic->base_addr +
+                               PLIC_ENABLE_OFFSET +
+                               (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET)),
+                   (num_sources + 8) / 8);
+  
+  // Set all priorities to 0 (equal priority -- don't assume that these are reset).
+  volatile_memzero ((uint8_t *)(this_plic->base_addr +
+                                PLIC_PRIORITY_OFFSET),
+                    (num_sources + 1) << PLIC_PRIORITY_SHIFT_PER_SOURCE);
+
+  // Set the threshold to 0.
+  volatile plic_threshold* threshold = (plic_threshold*)
+    (this_plic->base_addr +
+     PLIC_THRESHOLD_OFFSET +
+     (hart_id << PLIC_THRESHOLD_SHIFT_PER_TARGET));
+
+  *threshold = 0;
+  
+}
+
+void PLIC_set_threshold (plic_instance_t * this_plic,
+			 plic_threshold threshold){
+
+  unsigned long hart_id = read_csr(mhartid);  
+  volatile plic_threshold* threshold_ptr = (plic_threshold*) (this_plic->base_addr +
+                                                              PLIC_THRESHOLD_OFFSET +
+                                                              (hart_id << PLIC_THRESHOLD_SHIFT_PER_TARGET));
+
+  *threshold_ptr = threshold;
+
+}
+  
+
+void PLIC_enable_interrupt (plic_instance_t * this_plic, plic_source source){
+
+  unsigned long hart_id = read_csr(mhartid);
+  volatile uint8_t * current_ptr = (volatile uint8_t *)(this_plic->base_addr +
+                                                        PLIC_ENABLE_OFFSET +
+                                                        (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET) +
+                                                        (source >> 3));
+  uint8_t current = *current_ptr;
+  current = current | ( 1 << (source & 0x7));
+  *current_ptr = current;
+
+}
+
+void PLIC_disable_interrupt (plic_instance_t * this_plic, plic_source source){
+  
+  unsigned long hart_id = read_csr(mhartid);
+  volatile uint8_t * current_ptr = (volatile uint8_t *) (this_plic->base_addr +
+                                                         PLIC_ENABLE_OFFSET +
+                                                         (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET) +
+                                                         (source >> 3));
+  uint8_t current = *current_ptr;
+  current = current & ~(( 1 << (source & 0x7)));
+  *current_ptr = current;
+  
+}
+
+void PLIC_set_priority (plic_instance_t * this_plic, plic_source source, plic_priority priority){
+
+  if (this_plic->num_priorities > 0) {
+    volatile plic_priority * priority_ptr = (volatile plic_priority *)
+      (this_plic->base_addr +
+       PLIC_PRIORITY_OFFSET +
+       (source << PLIC_PRIORITY_SHIFT_PER_SOURCE));
+    *priority_ptr = priority;
+  }
+}
+
+plic_source PLIC_claim_interrupt(plic_instance_t * this_plic){
+  
+  unsigned long hart_id = read_csr(mhartid);
+
+  volatile plic_source * claim_addr = (volatile plic_source * )
+    (this_plic->base_addr +
+     PLIC_CLAIM_OFFSET +
+     (hart_id << PLIC_CLAIM_SHIFT_PER_TARGET));
+
+  return  *claim_addr;
+  
+}
+
+void PLIC_complete_interrupt(plic_instance_t * this_plic, plic_source source){
+  
+  unsigned long hart_id = read_csr(mhartid);
+  volatile plic_source * claim_addr = (volatile plic_source *) (this_plic->base_addr +
+                                                                PLIC_CLAIM_OFFSET +
+                                                                (hart_id << PLIC_CLAIM_SHIFT_PER_TARGET));
+  *claim_addr = source;
+  
+}
+

raven/bsp/drivers/plic/plic_driver.h

@@ -0,0 +1,51 @@
+// See LICENSE file for licence details
+
+#ifndef PLIC_DRIVER_H
+#define PLIC_DRIVER_H
+
+
+__BEGIN_DECLS
+
+#include "platform.h"
+
+typedef struct __plic_instance_t
+{
+  uintptr_t base_addr;
+
+  uint32_t num_sources;
+  uint32_t num_priorities;
+  
+} plic_instance_t;
+
+typedef uint32_t plic_source;
+typedef uint32_t plic_priority;
+typedef uint32_t plic_threshold;
+
+void PLIC_init (
+                plic_instance_t * this_plic,
+                uintptr_t         base_addr,
+                uint32_t num_sources,
+                uint32_t num_priorities
+                );
+
+void PLIC_set_threshold (plic_instance_t * this_plic,
+			 plic_threshold threshold);
+  
+void PLIC_enable_interrupt (plic_instance_t * this_plic,
+			    plic_source source);
+
+void PLIC_disable_interrupt (plic_instance_t * this_plic,
+			     plic_source source);
+  
+void PLIC_set_priority (plic_instance_t * this_plic,
+			plic_source source,
+			plic_priority priority);
+
+plic_source PLIC_claim_interrupt(plic_instance_t * this_plic);
+
+void PLIC_complete_interrupt(plic_instance_t * this_plic,
+			     plic_source source);
+
+__END_DECLS
+
+#endif

raven/bsp/env/common.mk

@@ -0,0 +1,62 @@
+# See LICENSE for license details.
+
+ifndef _SIFIVE_MK_COMMON
+_SIFIVE_MK_COMMON := # defined
+
+.PHONY: all
+all: $(TARGET)
+
+include $(BSP_BASE)/libwrap/libwrap.mk
+
+BOARD ?= freedom-e300-hifive1
+ENV_DIR = $(BSP_BASE)/env
+PLATFORM_DIR = $(ENV_DIR)/$(BOARD)
+
+#TARGET_FLAVOR := -march=rv32imac -mabi=ilp32 -mcmodel=medany -msmall-data-limit=8 -x assembler-with-cpp
+TARGET_FLAVOR := -march=rv32i -mabi=ilp32
+
+ASM_SRCS += $(ENV_DIR)/start.S
+ASM_SRCS += $(ENV_DIR)/entry.S
+C_SRCS += $(PLATFORM_DIR)/init.c
+
+LINKER_SCRIPT := $(PLATFORM_DIR)/link.lds
+
+INCLUDES += -I$(BSP_BASE)/include
+INCLUDES += -I$(BSP_BASE)/drivers/
+INCLUDES += -I$(ENV_DIR)
+INCLUDES += -I$(PLATFORM_DIR)
+
+TOOL_DIR ?= $(BSP_BASE)/../toolchain/bin
+
+CC := $(TOOL_DIR)/riscv64-unknown-elf-gcc ${TARGET_FLAVOR}
+AR := $(TOOL_DIR)/riscv64-unknown-elf-ar
+OBJDUMP := $(TOOL_DIR)/riscv64-unknown-elf-objdump
+
+LDFLAGS += -T $(LINKER_SCRIPT) -nostartfiles
+LDFLAGS += -L$(ENV_DIR)
+
+ASM_OBJS := $(ASM_SRCS:.S=.o)
+C_OBJS := $(C_SRCS:.c=.o)
+
+LINK_OBJS += $(ASM_OBJS) $(C_OBJS)
+LINK_DEPS += $(LINKER_SCRIPT)
+
+CLEAN_OBJS += $(TARGET) $(LINK_OBJS)
+
+CFLAGS += -g
+
+$(TARGET): $(LINK_OBJS) $(LINK_DEPS)
+	$(CC) $(CFLAGS) $(INCLUDES) $(LINK_OBJS) -o $@ $(LDFLAGS)
+	$(OBJDUMP) -d $(TARGET) > $(TARGET).dis
+
+$(ASM_OBJS): %.o: %.S $(HEADERS)
+	$(CC) $(CFLAGS) $(INCLUDES) -c -o $@ $<
+
+$(C_OBJS): %.o: %.c $(HEADERS)
+	$(CC) $(CFLAGS) $(INCLUDES) -include sys/cdefs.h -c -o $@ $<
+
+.PHONY: clean
+clean:
+	rm -f $(CLEAN_OBJS)
+
+endif # _SIFIVE_MK_COMMON

raven/bsp/env/entry.S

@@ -0,0 +1,97 @@
+// See LICENSE for license details
+
+#ifndef ENTRY_S
+#define ENTRY_S
+
+#include "encoding.h"
+#include "sifive/bits.h"
+
+  .section      .text.entry	
+  .align 2
+  .global trap_entry
+trap_entry:
+  addi sp, sp, -32*REGBYTES
+
+  STORE x1, 1*REGBYTES(sp)
+  STORE x2, 2*REGBYTES(sp)
+  STORE x3, 3*REGBYTES(sp)
+  STORE x4, 4*REGBYTES(sp)
+  STORE x5, 5*REGBYTES(sp)
+  STORE x6, 6*REGBYTES(sp)
+  STORE x7, 7*REGBYTES(sp)
+  STORE x8, 8*REGBYTES(sp)
+  STORE x9, 9*REGBYTES(sp)
+  STORE x10, 10*REGBYTES(sp)
+  STORE x11, 11*REGBYTES(sp)
+  STORE x12, 12*REGBYTES(sp)
+  STORE x13, 13*REGBYTES(sp)
+  STORE x14, 14*REGBYTES(sp)
+  STORE x15, 15*REGBYTES(sp)
+  STORE x16, 16*REGBYTES(sp)
+  STORE x17, 17*REGBYTES(sp)
+  STORE x18, 18*REGBYTES(sp)
+  STORE x19, 19*REGBYTES(sp)
+  STORE x20, 20*REGBYTES(sp)
+  STORE x21, 21*REGBYTES(sp)
+  STORE x22, 22*REGBYTES(sp)
+  STORE x23, 23*REGBYTES(sp)
+  STORE x24, 24*REGBYTES(sp)
+  STORE x25, 25*REGBYTES(sp)
+  STORE x26, 26*REGBYTES(sp)
+  STORE x27, 27*REGBYTES(sp)
+  STORE x28, 28*REGBYTES(sp)
+  STORE x29, 29*REGBYTES(sp)
+  STORE x30, 30*REGBYTES(sp)
+  STORE x31, 31*REGBYTES(sp)
+
+  csrr a0, mcause
+  csrr a1, mepc
+  mv a2, sp
+  call handle_trap
+  csrw mepc, a0
+
+  # Remain in M-mode after mret
+  li t0, MSTATUS_MPP
+  csrs mstatus, t0
+
+  LOAD x1, 1*REGBYTES(sp)
+  LOAD x2, 2*REGBYTES(sp)
+  LOAD x3, 3*REGBYTES(sp)
+  LOAD x4, 4*REGBYTES(sp)
+  LOAD x5, 5*REGBYTES(sp)
+  LOAD x6, 6*REGBYTES(sp)
+  LOAD x7, 7*REGBYTES(sp)
+  LOAD x8, 8*REGBYTES(sp)
+  LOAD x9, 9*REGBYTES(sp)
+  LOAD x10, 10*REGBYTES(sp)
+  LOAD x11, 11*REGBYTES(sp)
+  LOAD x12, 12*REGBYTES(sp)
+  LOAD x13, 13*REGBYTES(sp)
+  LOAD x14, 14*REGBYTES(sp)
+  LOAD x15, 15*REGBYTES(sp)
+  LOAD x16, 16*REGBYTES(sp)
+  LOAD x17, 17*REGBYTES(sp)
+  LOAD x18, 18*REGBYTES(sp)
+  LOAD x19, 19*REGBYTES(sp)
+  LOAD x20, 20*REGBYTES(sp)
+  LOAD x21, 21*REGBYTES(sp)
+  LOAD x22, 22*REGBYTES(sp)
+  LOAD x23, 23*REGBYTES(sp)
+  LOAD x24, 24*REGBYTES(sp)
+  LOAD x25, 25*REGBYTES(sp)
+  LOAD x26, 26*REGBYTES(sp)
+  LOAD x27, 27*REGBYTES(sp)
+  LOAD x28, 28*REGBYTES(sp)
+  LOAD x29, 29*REGBYTES(sp)
+  LOAD x30, 30*REGBYTES(sp)
+  LOAD x31, 31*REGBYTES(sp)
+
+  addi sp, sp, 32*REGBYTES
+  mret
+
+.weak handle_trap
+handle_trap:
+1:
+  j 1b
+	
+#endif

raven/bsp/env/freedom-e300-arty/init.c

@@ -0,0 +1,87 @@
+//See LICENSE for license details.
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "platform.h"
+#include "encoding.h"
+
+extern int main(int argc, char** argv);
+extern void trap_entry();
+
+static unsigned long get_cpu_freq()
+{
+  return 65000000;
+}
+
+unsigned long get_timer_freq()
+{
+  return get_cpu_freq();
+}
+
+uint64_t get_timer_value()
+{
+#if __riscv_xlen == 32
+  while (1) {
+    uint32_t hi = read_csr(mcycleh);
+    uint32_t lo = read_csr(mcycle);
+    if (hi == read_csr(mcycleh))
+      return ((uint64_t)hi << 32) | lo;
+  }
+#else
+  return read_csr(mcycle);
+#endif
+}
+
+static void uart_init(size_t baud_rate)
+{
+  GPIO_REG(GPIO_IOF_SEL) &= ~IOF0_UART0_MASK;
+  GPIO_REG(GPIO_IOF_EN) |= IOF0_UART0_MASK;
+  UART0_REG(UART_REG_DIV) = get_cpu_freq() / baud_rate - 1;
+  UART0_REG(UART_REG_TXCTRL) |= UART_TXEN;
+}
+
+
+#ifdef USE_PLIC
+extern void handle_m_ext_interrupt();
+#endif
+
+#ifdef USE_M_TIME
+extern void handle_m_time_interrupt();
+#endif
+
+uintptr_t handle_trap(uintptr_t mcause, uintptr_t epc)
+{
+  if (0){
+#ifdef USE_PLIC
+    // External Machine-Level interrupt from PLIC
+  } else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_EXT)) {
+    handle_m_ext_interrupt();
+#endif
+#ifdef USE_M_TIME
+    // External Machine-Level interrupt from PLIC
+  } else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_TIMER)){
+    handle_m_time_interrupt();
+#endif
+  }
+  else {
+    write(1, "Unhandled Trap:\n", 16);
+    _exit(1 + mcause);
+  }
+  return epc;
+}
+
+void _init()
+{
+  #ifndef NO_INIT
+  uart_init(115200);
+
+  printf("core freq at %d Hz\n", get_cpu_freq());
+
+  write_csr(mtvec, &trap_entry);
+  #endif
+}
+
+void _fini()
+{
+}

raven/bsp/env/freedom-e300-arty/link.lds

@@ -0,0 +1,167 @@
+OUTPUT_ARCH( "riscv" )
+
+ENTRY( _start )
+
+MEMORY
+{
+  flash (rxai!w) : ORIGIN = 0x20400000, LENGTH = 512M
+  ram (wxa!ri) : ORIGIN = 0x80000000, LENGTH = 16K
+}
+
+PHDRS
+{
+  flash PT_LOAD;
+  ram_init PT_LOAD;
+  ram PT_NULL;
+}
+
+SECTIONS
+{
+  __stack_size = DEFINED(__stack_size) ? __stack_size : 2K;
+
+  .init           :
+  {
+    KEEP (*(SORT_NONE(.init)))
+  } >flash AT>flash :flash
+
+  .text           :
+  {
+    *(.text.unlikely .text.unlikely.*)
+    *(.text.startup .text.startup.*)
+    *(.text .text.*)
+    *(.gnu.linkonce.t.*)
+  } >flash AT>flash :flash
+
+  .fini           :
+  {
+    KEEP (*(SORT_NONE(.fini)))
+  } >flash AT>flash :flash
+
+  PROVIDE (__etext = .);
+  PROVIDE (_etext = .);
+  PROVIDE (etext = .);
+
+  .rodata         :
+  {
+    *(.rdata)
+    *(.rodata .rodata.*)
+    *(.gnu.linkonce.r.*)
+  } >flash AT>flash :flash
+
+  . = ALIGN(4);
+
+  .preinit_array  :
+  {
+    PROVIDE_HIDDEN (__preinit_array_start = .);
+    KEEP (*(.preinit_array))
+    PROVIDE_HIDDEN (__preinit_array_end = .);
+  } >flash AT>flash :flash
+
+  .init_array     :
+  {
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))
+    KEEP (*(.init_array EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o ) .ctors))
+    PROVIDE_HIDDEN (__init_array_end = .);
+  } >flash AT>flash :flash
+
+  .fini_array     :
+  {
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))
+    KEEP (*(.fini_array EXCLUDE_FILE (*crtbegin.o *crtbegin?.o *crtend.o *crtend?.o ) .dtors))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+  } >flash AT>flash :flash
+
+  .ctors          :
+  {
+    /* gcc uses crtbegin.o to find the start of
+       the constructors, so we make sure it is
+       first.  Because this is a wildcard, it
+       doesn't matter if the user does not
+       actually link against crtbegin.o; the
+       linker won't look for a file to match a
+       wildcard.  The wildcard also means that it
+       doesn't matter which directory crtbegin.o
+       is in.  */
+    KEEP (*crtbegin.o(.ctors))
+    KEEP (*crtbegin?.o(.ctors))
+    /* We don't want to include the .ctor section from
+       the crtend.o file until after the sorted ctors.
+       The .ctor section from the crtend file contains the
+       end of ctors marker and it must be last */
+    KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .ctors))
+    KEEP (*(SORT(.ctors.*)))
+    KEEP (*(.ctors))
+  } >flash AT>flash :flash
+
+  .dtors          :
+  {
+    KEEP (*crtbegin.o(.dtors))
+    KEEP (*crtbegin?.o(.dtors))
+    KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .dtors))
+    KEEP (*(SORT(.dtors.*)))
+    KEEP (*(.dtors))
+  } >flash AT>flash :flash
+
+  .lalign         :
+  {
+    . = ALIGN(4);
+    PROVIDE( _data_lma = . );
+  } >flash AT>flash :flash
+
+  .dalign         :
+  {
+    . = ALIGN(4);
+    PROVIDE( _data = . );
+  } >ram AT>flash :ram_init
+
+  .data          :
+  {