Rust-USB support using riscv-blink c-code

riscv-rust-blink/.cargo/config

@@ -1,6 +1,6 @@
 [target.riscv32i-unknown-none-elf]
 rustflags = [
-  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tld/linker.ld",
 ]
 
 

riscv-rust-blink/Cargo.lock

@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.13"
@@ -24,6 +26,12 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a165d606cf084741d4ac3a28fb6e9b1eb0bd31f6cd999098cfddb0b2ab381dc0"
 
+[[package]]
+name = "cc"
+version = "1.0.71"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79c2681d6594606957bbb8631c4b90a7fcaaa72cdb714743a437b156d6a7eedd"
+
 [[package]]
 name = "fomu-pac"
 version = "0.0.4"
@@ -157,6 +165,7 @@ dependencies = [
 name = "riscv-rust-blink"
 version = "0.1.0"
 dependencies = [
+ "cc",
  "fomu-pac",
  "fomu-rt",
  "panic-halt",

riscv-rust-blink/Cargo.toml

@@ -12,6 +12,9 @@ fomu-rt  = "0.0.6"
 
 panic-halt = "0.2"
 
+[build-dependencies]
+cc = "1.0.71"
+
 [profile.release]
 # Keep debug information for release builds, for easier debugging.
 # It will be removed during the conversion to the .dfu file.

riscv-rust-blink/build.rs

@@ -0,0 +1,16 @@
+use cc;
+
+// Build the USB-Support from the riscv-blink c-code
+fn main() {
+    cc::Build::new()
+        .file("../riscv-blink/src/usb-dev.c")
+        .file("../riscv-blink/src/usb-epfifo.c")
+        .file("../riscv-blink/src/usb-eptri.c")
+        .file("../riscv-blink/src/usb.c")
+        .file("../riscv-blink/src/rgb.c")
+        .file("src/c/irq.c")
+        .include("../riscv-blink/include")
+        
+        .define("__vexriscv__", None)
+        .compile("fomu-usb");
+}

riscv-rust-blink/ld/linker.ld

@@ -0,0 +1,162 @@
+MEMORY
+{
+  RAM : ORIGIN = 0x10000000, LENGTH = 128K
+  FLASH : ORIGIN = 0x20040000, LENGTH = 2M - 0x40000
+}
+
+REGION_ALIAS("REGION_TEXT", FLASH);
+REGION_ALIAS("REGION_RODATA", FLASH);
+REGION_ALIAS("REGION_DATA", RAM);
+REGION_ALIAS("REGION_BSS", RAM);
+REGION_ALIAS("REGION_HEAP", RAM);
+REGION_ALIAS("REGION_STACK", RAM);
+
+PROVIDE(_stext = ORIGIN(REGION_TEXT));
+PROVIDE(_stack_start = ORIGIN(REGION_STACK) + LENGTH(REGION_STACK));
+PROVIDE(_max_hart_id = 0);
+PROVIDE(_hart_stack_size = 2K);
+PROVIDE(_heap_size = 0);
+
+PROVIDE(trap_handler = default_trap_handler);
+
+/* # Pre-initialization function */
+/* If the user overrides this using the `#[pre_init]` attribute or by creating a `__pre_init` function,
+   then the function this points to will be called before the RAM is initialized. */
+PROVIDE(__pre_init = default_pre_init);
+
+/* # Multi-processing hook function
+   fn _mp_hook() -> bool;
+
+   This function is called from all the harts and must return true only for one hart,
+   which will perform memory initialization. For other harts it must return false
+   and implement wake-up in platform-dependent way (e.g. after waiting for a user interrupt).
+*/
+PROVIDE(_mp_hook = default_mp_hook);
+
+SECTIONS
+{
+  .text.dummy (NOLOAD) :
+  {
+    /* This section is intended to make _stext address work */
+    . = _stext;
+  } > REGION_TEXT
+
+  .text _stext :
+  {
+    /* Put reset handler first in .text section so it ends up as the entry */
+    /* point of the program. */
+    KEEP(*(.init));
+    KEEP(*(.init.rust));
+    . = ALIGN(4);
+    KEEP(*(.trap));
+    KEEP(*(.trap.rust));
+
+    *(.text .text.*);
+  } > REGION_TEXT
+
+  .rodata : ALIGN(4)
+  {
+    *(.rodata .rodata.*);
+
+    /* 4-byte align the end (VMA) of this section.
+       This is required by LLD to ensure the LMA of the following .data
+       section will have the correct alignment. */
+    . = ALIGN(4);
+  } > REGION_RODATA
+
+  .data : ALIGN(4)
+  {
+    _sidata = LOADADDR(.data);
+    _sdata = .;
+    *(.ramtext .ramtext.*)
+
+    /* Must be called __global_pointer$ for linker relaxations to work. */
+    PROVIDE(__global_pointer$ = . + 0x800);
+    *(.sdata .sdata.* .sdata2 .sdata2.*);
+    *(.data .data.*);
+    . = ALIGN(4);
+    _edata = .;
+  } > REGION_DATA AT > REGION_RODATA
+
+  .bss (NOLOAD) :
+  {
+    _sbss = .;
+    *(.sbss .sbss.* .bss .bss.*);
+    . = ALIGN(4);
+    _ebss = .;
+  } > REGION_BSS
+
+  /* fictitious region that represents the memory available for the heap */
+  .heap (NOLOAD) :
+  {
+    _sheap = .;
+    . += _heap_size;
+    . = ALIGN(4);
+    _eheap = .;
+  } > REGION_HEAP
+
+  /* fake output .got section */
+  /* Dynamic relocations are unsupported. This section is only used to detect
+     relocatable code in the input files and raise an error if relocatable code
+     is found */
+  .got (INFO) :
+  {
+    KEEP(*(.got .got.*));
+  }
+
+  /* Discard .eh_frame, we are not doing unwind on panic so it is not needed */
+  /DISCARD/ :
+  {
+    *(.eh_frame);
+    *(.eh_frame_hdr);
+  }
+}
+
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* Do not exceed this mark in the error messages above                                    | */
+ASSERT(ORIGIN(REGION_TEXT) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_TEXT must be 4-byte aligned");
+
+ASSERT(ORIGIN(REGION_RODATA) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_RODATA must be 4-byte aligned");
+
+ASSERT(ORIGIN(REGION_DATA) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_DATA must be 4-byte aligned");
+
+ASSERT(ORIGIN(REGION_HEAP) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_HEAP must be 4-byte aligned");
+
+ASSERT(ORIGIN(REGION_TEXT) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_TEXT must be 4-byte aligned");
+
+ASSERT(ORIGIN(REGION_STACK) % 4 == 0, "
+ERROR(riscv-rt): the start of the REGION_STACK must be 4-byte aligned");
+
+ASSERT(_stext % 4 == 0, "
+ERROR(riscv-rt): `_stext` must be 4-byte aligned");
+
+ASSERT(_sdata % 4 == 0 && _edata % 4 == 0, "
+BUG(riscv-rt): .data is not 4-byte aligned");
+
+ASSERT(_sidata % 4 == 0, "
+BUG(riscv-rt): the LMA of .data is not 4-byte aligned");
+
+ASSERT(_sbss % 4 == 0 && _ebss % 4 == 0, "
+BUG(riscv-rt): .bss is not 4-byte aligned");
+
+ASSERT(_sheap % 4 == 0, "
+BUG(riscv-rt): start of .heap is not 4-byte aligned");
+
+ASSERT(_stext + SIZEOF(.text) < ORIGIN(REGION_TEXT) + LENGTH(REGION_TEXT), "
+ERROR(riscv-rt): The .text section must be placed inside the REGION_TEXT region.
+Set _stext to an address smaller than 'ORIGIN(REGION_TEXT) + LENGTH(REGION_TEXT)'");
+
+ASSERT(SIZEOF(.got) == 0, "
+.got section detected in the input files. Dynamic relocations are not
+supported. If you are linking to C code compiled using the `gcc` crate
+then modify your build script to compile the C code _without_ the
+-fPIC flag. See the documentation of the `gcc::Config.fpic` method for
+details.");
+
+/* Do not exceed this mark in the error messages above                                    | */

riscv-rust-blink/src/c/irq.c

@@ -0,0 +1,22 @@
+#include <generated/csr.h>
+#include <irq.h>
+#include <usb.h>
+#include <system.h>
+
+
+void isr(void) {
+    unsigned int irqs;
+
+    irqs = irq_pending() & irq_getmask();
+
+    if (irqs & (1 << USB_INTERRUPT)) {
+        usb_isr();
+    }
+
+}
+
+void irq_init() {
+    irq_setmask(0);
+    irq_setie(1);
+    csrw(mie, 0x880);
+}

riscv-rust-blink/src/main.rs

@@ -14,10 +14,37 @@ use timer::Timer;
 
 const SYSTEM_CLOCK_FREQUENCY: u32 = 12_000_000;
 
+
+// USB-support using the c-code from riscv-blink
+#[link(name = "fomu-usb", kind = "static")]
+extern "C" {
+    fn usb_init();
+    fn usb_connect();
+    fn irq_init();
+    fn isr();
+    fn _start_trap_rust();
+}
+
+// set irq handler and call c-implementation
+#[doc(hidden)]
+#[link_section = ".trap.rust"]
+#[no_mangle]
+fn trap_handler() {
+    unsafe {isr();}
+}
+
 // This is the entry point for the application.
 // It is not allowed to return.
 #[entry]
 fn main() -> ! {
+
+    // Call riscv-blink c-usb-initialization code
+    unsafe {
+        irq_init();
+        usb_init();
+        usb_connect();
+    }
+
     let peripherals = fomu_pac::Peripherals::take().unwrap();
 
     let mut rgb_control = rgb::RgbControl::new(peripherals.RGB);