From 5062ac0818f07bfe07714039c46018172a79ee76 Mon Sep 17 00:00:00 2001
From: Brian Cully <bjc@kublai.com>
Date: Wed, 3 Aug 2022 12:22:32 -0400
Subject: Blinking achieved.

---
 src/main.rs | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/main.rs b/src/main.rs
index 0f77639..c0d41d3 100755
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,10 +4,49 @@
 #![no_main]
 
 use core::arch::asm;
+use gd32vf103_pac::Peripherals;
 
 #[no_mangle]
 fn main(_hartid: usize) -> ! {
-    loop {}
+    // let peripherals = Peripherals::take().unwrap();
+    let peripherals = unsafe { Peripherals::steal() };
+
+    let rcu = peripherals.RCU;
+    // enable RCU_GPIOA
+    rcu.apb2en.write(|w| {
+        w.paen().set_bit()
+    });
+
+    let gpio = peripherals.GPIOA;
+    // led is gpioa pin 7 output push/pull 50mhz
+    gpio.ctl0.write(|w| unsafe {
+        // output mode, push-pull
+        w.ctl7().bits(0b00);
+        // 50 mhz output rate
+        w.md7().bits(0b11);
+        w
+    });
+
+    let mut led_on = false;
+    loop {
+        if led_on {
+            gpio.bc.write(|w| w.cr7().set_bit());
+            if gpio.octl.read().octl7().bit() {
+                panic!("not set");
+            }
+        } else {
+            gpio.bop.write(|w| w.bop7().set_bit());
+            if !gpio.octl.read().octl7().bit() {
+                panic!("set");
+            }
+        }
+        led_on = !led_on;
+
+        let mut a = 0;
+        for _ in 1..100_000 {
+            a = gpio.octl.read().bits();
+        }
+    }
 }
 
 #[naked]
@@ -27,12 +66,20 @@ unsafe extern "C" fn _start() -> ! {
         "csrr a0, mhartid",
         "la sp, _stack_top",
 
-        "j main",
+        "tail main",
         options(noreturn)
     )
 }
 
 #[panic_handler]
-fn panic(_info: &core::panic::PanicInfo) -> ! {
+fn panic(info: &core::panic::PanicInfo) -> ! {
+    if let Some(loc) = info.location() {
+        let _file = loc.file();
+        let _line = loc.line();
+        if let Some(_msg) = info.payload().downcast_ref::<&str>() {
+            loop {}
+        }
+        loop {}
+    }
     loop {}
 }
-- 
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