Implement accessing FPSCR

asm-fpu.s

@@ -0,0 +1,21 @@
+  .cfi_sections .debug_frame
+
+  .section .text.__get_FPSCR
+  .global __get_FPSCR
+  .thumb_func
+  .cfi_startproc
+__get_FPSCR:
+  vmrs r0, fpscr
+  bx lr
+  .cfi_endproc
+  .size __get_FPSCR, . - __get_FPSCR
+
+  .section .text.__set_FPSCR
+  .global __set_FPSCR
+  .thumb_func
+  .cfi_startproc
+__set_FPSCR:
+  vmsr fpscr, r0
+  bx lr
+  .cfi_endproc
+  .size __set_FPSCR, . - __set_FPSCR

assemble.sh

@@ -17,10 +17,11 @@ arm-none-eabi-as -g -march=armv7-m asm-v7.s -o bin/$crate-v7.o
 ar crs bin/thumbv7m-none-eabi.a bin/$crate.o bin/$crate-v7.o
 
 arm-none-eabi-as -g -march=armv7e-m asm.s -o bin/$crate.o
-arm-none-eabi-as -g -march=armv7e-m asm-v7.s -o bin/$crate-v7.o
+arm-none-eabi-as -g -march=armv7e-m asm-fpu.s -mfpu=fpv4-sp-d16 -o bin/$crate-v7-fpu.o
 arm-none-eabi-as -g -march=armv7e-m asm-cm7-r0p1.s -o bin/$crate-cm7-r0p1.o
+arm-none-eabi-as -g -march=armv7e-m asm-v7.s -o bin/$crate-v7.o
 ar crs bin/thumbv7em-none-eabi.a bin/$crate.o bin/$crate-v7.o bin/$crate-cm7-r0p1.o
-ar crs bin/thumbv7em-none-eabihf.a bin/$crate.o bin/$crate-v7.o bin/$crate-cm7-r0p1.o
+ar crs bin/thumbv7em-none-eabihf.a bin/$crate.o bin/$crate-v7.o bin/$crate-cm7-r0p1.o bin/$crate-v7-fpu.o
 
 arm-none-eabi-as -g -march=armv8-m.base asm.s -o bin/$crate.o
 arm-none-eabi-as -g -march=armv8-m.base asm-v8.s -o bin/$crate-v8.o
@@ -30,11 +31,14 @@ arm-none-eabi-as -g -march=armv8-m.main asm.s -o bin/$crate.o
 arm-none-eabi-as -g -march=armv8-m.main asm-v7.s -o bin/$crate-v7.o
 arm-none-eabi-as -g -march=armv8-m.main asm-v8.s -o bin/$crate-v8.o
 arm-none-eabi-as -g -march=armv8-m.main asm-v8-main.s -o bin/$crate-v8-main.o
+arm-none-eabi-as -g -march=armv7e-m asm-fpu.s -mfpu=fpv5-sp-d16 -o bin/$crate-v8-fpu.o
 ar crs bin/thumbv8m.main-none-eabi.a bin/$crate.o bin/$crate-v7.o bin/$crate-v8.o bin/$crate-v8-main.o
-ar crs bin/thumbv8m.main-none-eabihf.a bin/$crate.o bin/$crate-v7.o bin/$crate-v8.o bin/$crate-v8-main.o
+ar crs bin/thumbv8m.main-none-eabihf.a bin/$crate.o bin/$crate-v7.o bin/$crate-v8.o bin/$crate-v8-main.o bin/$crate-v8-fpu.o
 
 rm bin/$crate.o
 rm bin/$crate-v7.o
+rm bin/$crate-v7-fpu.o
+rm bin/$crate-v8-fpu.o
 rm bin/$crate-cm7-r0p1.o
 rm bin/$crate-v8.o
 rm bin/$crate-v8-main.o

src/register/fpscr.rs

@@ -0,0 +1,343 @@
+//! Floating-point Status Control Register
+
+/// Floating-point Status Control Register
+#[allow(clippy::missing_inline_in_public_items)]
+#[derive(Clone, Copy, Debug)]
+pub struct Fpscr {
+    bits: u32,
+}
+
+impl Fpscr {
+    /// Creates a `Fspcr` value from raw bits.
+    #[inline]
+    pub fn from_bits(bits: u32) -> Self {
+        Self { bits }
+    }
+
+    /// Returns the contents of the register as raw bits
+    #[inline]
+    pub fn bits(self) -> u32 {
+        self.bits
+    }
+
+    /// Read the Negative condition code flag
+    #[inline]
+    pub fn n(self) -> bool {
+        self.bits & (1 << 31) != 0
+    }
+
+    /// Sets the Negative condition code flag
+    #[inline]
+    pub fn set_n(&mut self, n: bool) {
+        let mask = 1 << 31;
+        match n {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Zero condition code flag
+    #[inline]
+    pub fn z(self) -> bool {
+        self.bits & (1 << 30) != 0
+    }
+
+    /// Sets the Zero condition code flag
+    #[inline]
+    pub fn set_z(&mut self, z: bool) {
+        let mask = 1 << 30;
+        match z {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Carry condition code flag
+    #[inline]
+    pub fn c(self) -> bool {
+        self.bits & (1 << 29) != 0
+    }
+
+    /// Sets the Carry condition code flag
+    #[inline]
+    pub fn set_c(&mut self, c: bool) {
+        let mask = 1 << 29;
+        match c {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Overflow condition code flag
+    #[inline]
+    pub fn v(self) -> bool {
+        self.bits & (1 << 28) != 0
+    }
+
+    /// Sets the Zero condition code flag
+    #[inline]
+    pub fn set_v(&mut self, v: bool) {
+        let mask = 1 << 28;
+        match v {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Alternative Half Precision bit
+    #[inline]
+    pub fn ahp(self) -> bool {
+        self.bits & (1 << 26) != 0
+    }
+
+    /// Sets the Alternative Half Precision bit
+    #[inline]
+    pub fn set_ahp(&mut self, ahp: bool) {
+        let mask = 1 << 26;
+        match ahp {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Default NaN mode bit
+    #[inline]
+    pub fn dn(self) -> bool {
+        self.bits & (1 << 25) != 0
+    }
+
+    /// Sets the Default NaN mode bit
+    #[inline]
+    pub fn set_dn(&mut self, dn: bool) {
+        let mask = 1 << 25;
+        match dn {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Flush to Zero mode bit
+    #[inline]
+    pub fn fz(self) -> bool {
+        self.bits & (1 << 24) != 0
+    }
+
+    /// Sets the Flush to Zero mode bit
+    #[inline]
+    pub fn set_fz(&mut self, fz: bool) {
+        let mask = 1 << 24;
+        match fz {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Rounding Mode control field
+    #[inline]
+    pub fn rmode(self) -> RMode {
+        match (self.bits & (3 << 22)) >> 22 {
+            0 => RMode::Nearest,
+            1 => RMode::PlusInfinity,
+            2 => RMode::MinusInfinity,
+            _ => RMode::Zero,
+        }
+    }
+
+    /// Sets the Rounding Mode control field
+    #[inline]
+    pub fn set_rmode(&mut self, rmode: RMode) {
+        let mask = 3 << 22;
+        match rmode {
+            RMode::Nearest => self.bits = self.bits & !mask,
+            RMode::PlusInfinity => self.bits = (self.bits & !mask) | (1 << 22),
+            RMode::MinusInfinity => self.bits = (self.bits & !mask) | (2 << 22),
+            RMode::Zero => self.bits = self.bits | mask,
+        }
+    }
+
+    /// Read the Input Denormal cumulative exception bit
+    #[inline]
+    pub fn idc(self) -> bool {
+        self.bits & (1 << 7) != 0
+    }
+
+    /// Sets the Input Denormal cumulative exception bit
+    #[inline]
+    pub fn set_idc(&mut self, idc: bool) {
+        let mask = 1 << 7;
+        match idc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Inexact cumulative exception bit
+    #[inline]
+    pub fn ixc(self) -> bool {
+        self.bits & (1 << 4) != 0
+    }
+
+    /// Sets the Inexact cumulative exception bit
+    #[inline]
+    pub fn set_ixc(&mut self, ixc: bool) {
+        let mask = 1 << 4;
+        match ixc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Underflow cumulative exception bit
+    #[inline]
+    pub fn ufc(self) -> bool {
+        self.bits & (1 << 3) != 0
+    }
+
+    /// Sets the Underflow cumulative exception bit
+    #[inline]
+    pub fn set_ufc(&mut self, ufc: bool) {
+        let mask = 1 << 3;
+        match ufc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Overflow cumulative exception bit
+    #[inline]
+    pub fn ofc(self) -> bool {
+        self.bits & (1 << 2) != 0
+    }
+
+    /// Sets the Overflow cumulative exception bit
+    #[inline]
+    pub fn set_ofc(&mut self, ofc: bool) {
+        let mask = 1 << 2;
+        match ofc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Division by Zero cumulative exception bit
+    #[inline]
+    pub fn dzc(self) -> bool {
+        self.bits & (1 << 1) != 0
+    }
+
+    /// Sets the Division by Zero cumulative exception bit
+    #[inline]
+    pub fn set_dzc(&mut self, dzc: bool) {
+        let mask = 1 << 1;
+        match dzc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+
+    /// Read the Invalid Operation cumulative exception bit
+    #[inline]
+    pub fn ioc(self) -> bool {
+        self.bits & (1 << 0) != 0
+    }
+
+    /// Sets the Invalid Operation cumulative exception bit
+    #[inline]
+    pub fn set_ioc(&mut self, ioc: bool) {
+        let mask = 1 << 0;
+        match ioc {
+            true => self.bits |= mask,
+            false => self.bits &= !mask,
+        }
+    }
+}
+
+/// Rounding mode
+#[allow(clippy::missing_inline_in_public_items)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum RMode {
+    /// Round to Nearest (RN) mode. This is the reset value.
+    Nearest,
+    /// Round towards Plus Infinity (RP) mode.
+    PlusInfinity,
+    /// Round towards Minus Infinity (RM) mode.
+    MinusInfinity,
+    /// Round towards Zero (RZ) mode.
+    Zero,
+}
+
+impl RMode {
+    /// Is Nearest the current rounding mode?
+    #[inline]
+    pub fn is_nearest(self) -> bool {
+        self == RMode::Nearest
+    }
+
+    /// Is Plus Infinity the current rounding mode?
+    #[inline]
+    pub fn is_plus_infinity(self) -> bool {
+        self == RMode::PlusInfinity
+    }
+
+    /// Is Minus Infinity the current rounding mode?
+    #[inline]
+    pub fn is_minus_infinity(self) -> bool {
+        self == RMode::MinusInfinity
+    }
+
+    /// Is Zero the current rounding mode?
+    #[inline]
+    pub fn is_zero(self) -> bool {
+        self == RMode::Zero
+    }
+}
+
+/// Read the FPSCR register
+#[inline]
+pub fn read() -> Fpscr {
+    match () {
+        #[cfg(all(cortex_m, feature = "inline-asm"))]
+        () => {
+            let r: u32;
+            unsafe {
+                llvm_asm!("vmrs $0, fpscr" : "=r"(r) ::: "volatile");
+            }
+            Fpscr::from_bits(r)
+        }
+
+        #[cfg(all(cortex_m, not(feature = "inline-asm")))]
+        () => unsafe {
+            extern "C" {
+                fn __get_FPSCR() -> u32;
+            }
+            Fpscr::from_bits(__get_FPSCR())
+        },
+
+        #[cfg(not(cortex_m))]
+        () => unimplemented!(),
+    }
+}
+
+/// Set the value of the FPSCR register
+#[inline]
+pub unsafe fn write(_fspcr: Fpscr) {
+    match () {
+        #[cfg(all(cortex_m, feature = "inline-asm"))]
+        () => {
+            let bits = _fspcr.bits();
+            llvm_asm!("vmsr fpscr, $0" :: "r"(bits) :: "volatile");
+        }
+
+        #[cfg(all(cortex_m, not(feature = "inline-asm")))]
+        () => {
+            extern "C" {
+                fn __set_FPSCR(bits: u32);
+            }
+
+            __set_FPSCR(_fspcr.bits());
+        }
+
+        #[cfg(not(cortex_m))]
+        () => unimplemented!(),
+    }
+}