the only thing that doesn't work is the buffer, which is bad, but at least the board lights up

.cargo/config.toml

@@ -1,10 +1,9 @@
-[build]
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
-target = "thumbv7em-none-eabihf"
+runner = "arm-none-eabi-gdb -q -x .gdbinit"
-
-[target.thumbv7em-none-eabihf]
-# Using probe-rs for flashing
-runner = "probe-rs run --chip STM32F469NIx"
 
 rustflags = [
     "-C", "link-arg=-Tlink.x",
 ]
+
+[build]
+target = "thumbv7em-none-eabihf"

.gdbinit

@@ -17,7 +17,7 @@ break rust_begin_unwind
 # end
 
 # *try* to stop at the user entry point (it might be gone due to inlining)
-break main
+# break main
 
 monitor arm semihosting enable
 

build.rs

@@ -1,19 +0,0 @@
-// I totally understand this and it's not copied from
-// https://github.com/cyang812/rust_stm32f469i/blob/main/led_blinky/
-// hehe
-use std::env;
-use std::fs;
-use std::path::PathBuf;
-
-fn main() {
-    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
-    fs::write(out.join("memory.x"), include_bytes!("memory.x")).unwrap();
-    println!("cargo:rustc-link-search={}", out.display());
-
-    // Only link CCM script when the feature is enabled.
-    // Enable with: cargo build --features ccmram
-    if env::var_os("CARGO_FEATURE_CCMRAM").is_some() {
-        fs::write(out.join("ccmram.x"), include_bytes!("ccmram.x")).unwrap();
-        println!("cargo:rustc-link-arg=-Tccmram.x");
-    }
-}

ccmram.x

@@ -1,10 +0,0 @@
-/* Extra linker script to place data into CCM SRAM */
-SECTIONS
-{
-    .ccmram (NOLOAD) :
-    {
-        . = ALIGN(4);
-        *(.ccmram .ccmram.*)
-        . = ALIGN(4);
-    } > CCMRAM
-} INSERT AFTER .rodata;

memory.x

@@ -1,9 +1,7 @@
-/* Memory layout of the STM32F469NI */
 MEMORY
 {
   FLASH : ORIGIN = 0x08000000, LENGTH = 2M
-    RAM : ORIGIN = 0x20000000, LENGTH = 384K
+  RAM : ORIGIN = 0x20000000, LENGTH = 320K
-    CCMRAM : ORIGIN = 0x10000000, LENGTH = 64K
   SDRAM : ORIGIN = 0xC0000000, LENGTH = 16M
 }
 
@@ -11,8 +9,8 @@ SECTIONS
 {
 	.sdram (NOLOAD) :
 	{
-        *(.sdram .sdram.*);
+			. = ALIGN(4);
+			*(.sdram)
+			. = ALIGN(4);
 	} >SDRAM
 }
-
-_stack_start = ORIGIN(RAM) + LENGTH(RAM);

src/main.rs

@@ -10,13 +10,10 @@ use crate::hal::{
     prelude::*,
 };
 use cortex_m_rt::entry;
-use defmt_rtt as _;
 use otm8009a::{Otm8009A, Otm8009AConfig};
-use panic_probe as _;
+use panic_halt as _;
 use stm32f4xx_hal::{self as hal, ltdc, rcc::Config};
 
-defmt::timestamp!("{=u32}", 0u32);
-
 const WIDTH: usize = 480;
 const HEIGHT: usize = 800;
 
@@ -175,6 +172,7 @@ fn main() -> ! {
     });
     while fmc.sdsr().read().busy().bit_is_set() {}
     fmc.sdrtr().write(|w| w.count().set(1385));
+    while fmc.sdsr().read().busy().bit_is_set() {}
 
     let mut lcd_reset = gpioh.ph7.into_push_pull_output();
     lcd_reset.set_low();
@@ -193,12 +191,12 @@ fn main() -> ! {
         DISPLAY_CONFIGURATION,
         Some(hse_freq),
     );
-    display.enable_layer(ltdc::Layer::L1);
     display.config_layer(
         ltdc::Layer::L1,
         unsafe { &mut BUFF[..] },
         PixelFormat::ARGB8888,
     );
+    display.enable_layer(ltdc::Layer::L1);
 
     let dsi_pll_config = unsafe { DsiPllConfig::manual(125, 2, 0, 4) };
     let dsi_config = DsiConfig {
@@ -239,7 +237,6 @@ fn main() -> ! {
     dsi_host.enable_bus_turn_around();
     dsi_host.set_command_mode_transmission_kind(DsiCmdModeTransmissionKind::AllInHighSpeed);
     dsi_host.force_rx_low_power(true);
-    dsi_host.enable_color_test();
 
     let mut otm = Otm8009A::new();
     otm.init(
@@ -255,6 +252,11 @@ fn main() -> ! {
     )
     .unwrap();
 
+    unsafe {
+        (0..480 * 800).for_each(|i| BUFF[i] = 0xFF0000FF);
+    }
+    display.reload();
+
     gpiog.pg6.into_push_pull_output().set_low();
     gpiod.pd4.into_push_pull_output().set_low();
     gpiod.pd5.into_push_pull_output().set_low();

src/test.rs

@@ -0,0 +1,18 @@
+#![no_main]
+#![no_std]
+use crate::hal::prelude::*;
+use cortex_m_rt::entry;
+use panic_halt as _;
+use stm32f4xx_hal::{self as hal, rcc::Config};
+
+#[entry]
+fn main() -> ! {
+    let peripherals = hal::pac::Peripherals::take().unwrap();
+    let mut rcc = peripherals.RCC.freeze(Config::hse(8.MHz()));
+
+    let gpiok = peripherals.GPIOK.split(&mut rcc);
+    let mut led = gpiok.pk3.into_push_pull_output();
+    led.set_low();
+
+    loop {}
+}