finally working oh my gash

.gitignore

@@ -1,2 +1,4 @@
 .zig-cache/
 main
+test/
+test.zip

flake.nix

@@ -20,6 +20,7 @@
           echo "Entering Zig Master Environment"
           echo "Zig: $(zig version)"
           echo "ZLS: $(zls --version)"
+          echo "openocd -f board/ek-tm4c123gxl.cfg -c \"program tiva/zig-out/bin/tiva-app verify reset exit\""
         '';
       };
     };

tiva/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const target = b.resolveTargetQuery(.{
         .cpu_arch = .thumb,
         .os_tag = .freestanding,
-        .abi = .eabi,
+        .abi = .eabihf,
         .cpu_model = .{ .explicit = &std.Target.arm.cpu.cortex_m4 },
     });
 
@@ -29,6 +29,10 @@ pub fn build(b: *std.Build) void {
         .root_module = tiva_module,
     });
 
+    const bin = elf.addObjCopy(.{ .format = .bin });
+    const install_bin = b.addInstallBinFile(bin.getOutput(), "tiva-app.bin");
+    b.getInstallStep().dependOn(&install_bin.step);
+
     elf.root_module.strip = true; 
     elf.root_module.omit_frame_pointer = true;
     elf.root_module.unwind_tables = .none;

tiva/src/main.zig

@@ -3,23 +3,46 @@ const cmsis = @cImport({
     @cInclude("TM4C123GH6PM.h");
 });
 
-const GPIO_PORTF_CLK_EN: u32 = 0x20;  // Bit 5 (Port F)
-const GPIO_PORTF_PIN1_EN: u32 = 0x02; // Bit 1
+const GPIO_PORTF_CLK_EN = @as(u32, 0x20); // Bit 5 (Port F)
+const GPIO_PORTF_PIN1_EN = @as(u32, 0x02); // Bit 1
 
-const LED_ON1: u32 = 0x02;
+const LED_RED = @as(u32, 0x02);
 
-export fn _start() noreturn {
+// export const vector_table linksection(".isr_vector") = [2]usize{
+//     0x20008000,
+//     @intFromPtr(&_start),
+// };
+
+const VectorEntry = extern union {
+    stack_top: u32,
+    handler: *const fn () callconv(.c) noreturn,
+};
+
+export const vector_table linksection(".vector_table") = [_]VectorEntry{
+    .{ .stack_top = 0x20008000 },
+    .{ .handler = &_start },
+};
+
+export fn _start() callconv(.c) noreturn {
+    cmsis.SYSCTL.*.RCGC2 |= GPIO_PORTF_CLK_EN;
     cmsis.SYSCTL.*.RCGCGPIO |= GPIO_PORTF_CLK_EN;
     _ = cmsis.SYSCTL.*.RCGCGPIO;
+    _ = cmsis.SYSCTL.*.RCGCGPIO;
+    _ = cmsis.SYSCTL.*.RCGCGPIO;
 
-    cmsis.GPIOF.*.DEN |= GPIO_PORTF_PIN1_EN;
-    cmsis.GPIOF.*.DIR |= GPIO_PORTF_PIN1_EN;
+    cmsis.SYSCTL.*.GPIOHBCTL |= GPIO_PORTF_CLK_EN;
 
-    const DELAY_VALUE = 4000000;
+    cmsis.GPIOF_AHB.*.DEN |= GPIO_PORTF_PIN1_EN;
+    cmsis.GPIOF_AHB.*.DIR |= GPIO_PORTF_PIN1_EN;
+    // cmsis.GPIOF_AHB.*.DATA ^= LED_RED;
+
+    const gpiof_data_pf1: *volatile u32 = @ptrFromInt(@intFromPtr(cmsis.GPIOF_AHB) + (LED_RED << 2));
+
+    const DELAY_VALUE = 400000;
     while (true) {
-        cmsis.GPIOF.*.DATA = LED_ON1; // LED On
+        gpiof_data_pf1.* = LED_RED; // LED On
         Delay(DELAY_VALUE);
-        cmsis.GPIOF.*.DATA = 0; // LED On
+        gpiof_data_pf1.* = 0; // LED off
         Delay(DELAY_VALUE);
     }
 }