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| author | Clyne Sullivan <clyne@bitgloo.com> | 2024-10-05 12:44:04 -0400 |
|---|---|---|
| committer | Clyne Sullivan <clyne@bitgloo.com> | 2024-10-05 12:44:04 -0400 |
| commit | e7b04608254c414d0e770acde071b651ea1472cf (patch) | |
| tree | ca2e1d387fc70613054f75ee90d6a6a8cd760351 | |
| parent | f529a3b0f8ee24229997e995021a2ee8cb25f065 (diff) | |
toggle gpio
| -rw-r--r-- | build.zig | 1 | ||||
| -rw-r--r-- | src/bootstrap.s | 2 | ||||
| -rw-r--r-- | src/main.zig | 38 |
3 files changed, 39 insertions, 2 deletions
@@ -3,6 +3,7 @@ const std = @import("std"); pub fn build(b: *std.Build) void { const target = b.resolveTargetQuery(.{ .cpu_arch = .thumb, + .cpu_model = .{ .explicit = &std.Target.arm.cpu.cortex_m4 }, .os_tag = .freestanding, .abi = .none }); diff --git a/src/bootstrap.s b/src/bootstrap.s index 22f66f0..5e71da0 100644 --- a/src/bootstrap.s +++ b/src/bootstrap.s @@ -23,7 +23,7 @@ fault5: b fault_handler .section .bss -.skip 128 +.skip 2048 stack_top: .section .isr_vector diff --git a/src/main.zig b/src/main.zig index de602dd..0fe4497 100644 --- a/src/main.zig +++ b/src/main.zig @@ -3,8 +3,44 @@ //! is to delete this file and start with root.zig instead. //const std = @import("std"); +const gpio = packed struct { + moder: u32, + otyper: u32, + ospeedr: u32, + pupdr: u32, + idr: u32, + odr: u32, + bsrr: u32, + lckr: u32, + afrl: u32, + afrh: u32, + brr: u32, + ascr: u32, +}; + +const cpu = struct { + pub fn interrupt_disable() void { + asm volatile("cpsid i"); + } + + pub fn interrupt_enable() void { + asm volatile("cpsie i"); + } +}; + +const gpioa: *gpio = @ptrFromInt(0x48000000); +const rcc: *[39]u32 = @ptrFromInt(0x40021000); + export fn _start() callconv(.C) noreturn { - while (true) {} + cpu.interrupt_disable(); + + rcc[19] |= 1; // gpioaen + gpioa.moder &= ~@as(u32, 0x3 << (5 * 2)); + gpioa.moder |= (1 << (5 * 2)); + + while (true) { + gpioa.odr ^= (1 << 5); + } } export fn fault_handler() callconv(.C) void { |