commit c77975b17de56cc8e316243c27d98880f2921cc6
parent c8030e031cbd861761a7b54caea213fb3b2fe2f6
Author: Sylvia Ivory <git@sivory.net>
Date: Thu, 15 Jan 2026 21:43:27 -0800
Remove util.zig
Diffstat:
8 files changed, 68 insertions(+), 41 deletions(-)
diff --git a/build.zig b/build.zig
@@ -4,11 +4,18 @@ const config = @import("build.zig.zon");
const add_exe_ty = *const fn (exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build) anyerror!*std.Build.Step.Compile;
fn add_exe_fake_pi(exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build) !*std.Build.Step.Compile {
+ const pi = b.createModule(.{
+ .root_source_file = b.path("fake-pi/pi.zig"),
+ .target = b.graph.host,
+ .optimize = .ReleaseSafe,
+ });
+
const boot = b.createModule(.{
.root_source_file = path,
.target = b.graph.host,
.optimize = .ReleaseSafe,
});
+ boot.addImport("pi", pi);
const fake_pi = b.createModule(.{
.root_source_file = b.path("fake-pi/main.zig"),
@@ -16,7 +23,6 @@ fn add_exe_fake_pi(exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build
.optimize = .ReleaseFast,
.link_libc = true,
});
-
fake_pi.addImport("boot", boot);
// TODO; C should get its own module so we can have fake-pi be in debug for faster comp
@@ -51,9 +57,15 @@ fn add_exe_real(exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build) !
.abi = .eabi,
};
+ const pi = b.createModule(.{
+ .root_source_file = b.path("pi/root.zig"),
+ .target = b.graph.host,
+ .optimize = .ReleaseSafe,
+ });
+
// BCM2835 is **very specifically** the ARM1176JZF-S
// https://www.raspberrypi.com/documentation/computers/processors.html
- const pi = b.createModule(.{
+ const boot = b.createModule(.{
.root_source_file = path,
.target = b.resolveTargetQuery(target),
.optimize = .ReleaseSafe,
@@ -63,12 +75,13 @@ fn add_exe_real(exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build) !
.link_libc = false,
.no_builtin = true,
});
- pi.addAssemblyFile(b.path("start.s"));
+ boot.addAssemblyFile(b.path("start.s"));
+ boot.addImport("pi", pi);
const exe = b.addExecutable(.{
.name = exe_name,
.linkage = .static,
- .root_module = pi,
+ .root_module = boot,
});
exe.setLinkerScript(b.path("linker.ld"));
diff --git a/fake-pi/pi.zig b/fake-pi/pi.zig
@@ -0,0 +1,21 @@
+pub const mem = struct {
+ const Operation = enum {
+ Read,
+ Write,
+ General,
+ };
+
+ pub inline fn barrier(op: Operation) void {
+ _ = op;
+ }
+
+ pub extern fn put_u32(address: *u32, value: u32) void;
+ pub inline fn put_u32_barrier(address: *u32, value: u32) void {
+ return put_u32(address, value);
+ }
+
+ pub extern fn get_u32(address: *u32) u32;
+ pub inline fn get_u32_barrier(address: *u32) u32 {
+ return get_u32(address);
+ }
+};
diff --git a/pi/mem.zig b/pi/mem.zig
@@ -37,7 +37,7 @@ pub inline fn put_u32(address: *u32, value: u32) void {
asm volatile ("str %[value], [%[address]]"
:
: [value] "r" (value),
- [address] "=r" (address),
+ [address] "r" (address),
);
}
@@ -51,8 +51,8 @@ pub inline fn put_u32_barrier(
pub inline fn get_u32(address: *u32) u32 {
return asm volatile ("str %[result], [%[address]]"
- : [result] "r" (-> u32),
- : [address] "=r" (address),
+ : [result] "=r" (-> u32),
+ : [address] "r" (address),
);
}
diff --git a/pi/root.zig b/pi/root.zig
@@ -0,0 +1 @@
+pub const mem = @import("./mem.zig");
diff --git a/src/devices/gpio.zig b/src/devices/gpio.zig
@@ -1,5 +1,5 @@
const std = @import("std");
-const util = @import("../util.zig");
+const mem = @import("pi").mem;
// Page 90, Table 6-1: GPIO Register Assignment
const BASE_OFFSET: usize = 0x0020_0000;
@@ -53,10 +53,10 @@ pub fn fn_sel(pin: u8, sel: FunctionSelect) Error!void {
const offset: u5 = @truncate((pin % GPIO_PER_FSEL) * 3);
const mask = ~(@as(u32, 0b111) << offset);
- var state = util.get_u32(address);
+ var state = mem.get_u32(address);
state &= mask;
state |= (@as(u32, @intCast(@intFromEnum(sel))) << offset);
- util.put_u32(address, state);
+ mem.put_u32(address, state);
}
fn addr_bitset(pin: u8, address: *u32) void {
@@ -65,7 +65,7 @@ fn addr_bitset(pin: u8, address: *u32) void {
// We don't want to preserve the old value
// SET and CLR are separated for this purpose
- util.put_u32(address, mask);
+ mem.put_u32(address, mask);
}
// Turn on
@@ -105,7 +105,7 @@ pub fn read(pin: u8) Error!bool {
const offset: u5 = @truncate(pin % 32);
const mask = (@as(u32, 1) << offset);
- return (util.get_u32(address) & mask) == mask;
+ return (mem.get_u32(address) & mask) == mask;
}
pub fn write(pin: u8, state: bool) Error!void {
diff --git a/src/devices/timer.zig b/src/devices/timer.zig
@@ -1,7 +1,5 @@
const std = @import("std");
-
-const barrier = @import("barrier.zig");
-const util = @import("../util.zig");
+const mem = @import("pi").mem;
var base_address: usize = 0;
@@ -14,11 +12,8 @@ pub fn initialize(base_addr: u32) void {
}
pub fn current_count() u64 {
- var b = barrier.obtain();
- defer b.release();
-
- const upper = util.get_u32(base_address + COUNTER_UPPER_OFFSET);
- const lower = util.get_u32(base_address + COUNTER_LOWER_OFFSET);
+ const upper = mem.get_u32_barrier(base_address + COUNTER_UPPER_OFFSET);
+ const lower = mem.get_u32_barrier(base_address + COUNTER_LOWER_OFFSET);
const extended: u64 = @intCast(upper);
return (extended << 32) | lower;
diff --git a/src/labs/2-gpio.zig b/src/labs/2-gpio.zig
@@ -1,20 +1,28 @@
+const std = @import("std");
+
const gpio = @import("../devices/gpio.zig");
-const util = @import("../util.zig");
const led0 = 20;
const led1 = 21;
const led2 = 27;
const act = 47;
+// TODO; replace with actual cycles
+fn delay_cycles(count: usize) void {
+ for (0..count) |_| {
+ std.atomic.spinLoopHint();
+ }
+}
+
pub fn blink_1() !void {
try gpio.set_output(led0);
for (0..10) |_| {
try gpio.set_on(led0);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
try gpio.set_off(led0);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
}
try gpio.set_on(led0);
@@ -27,11 +35,11 @@ pub fn blink_2() !void {
for (0..10) |_| {
try gpio.set_on(led0);
try gpio.set_off(led1);
- util.delay_cycles(3000000);
+ delay_cycles(3000000);
try gpio.set_off(led0);
try gpio.set_on(led1);
- util.delay_cycles(3000000);
+ delay_cycles(3000000);
}
}
@@ -50,7 +58,7 @@ pub fn loopback() !void {
try gpio.write(output, v);
try gpio.write(led1, try gpio.read(input));
- util.delay_cycles(1500000);
+ delay_cycles(1500000);
v = !v;
}
}
@@ -60,10 +68,10 @@ pub fn act_blink() !void {
for (0..10) |_| {
try gpio.set_on(act);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
try gpio.set_off(act);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
}
try gpio.set_on(act);
@@ -80,13 +88,13 @@ pub fn all() !void {
try gpio.set_on(led1);
try gpio.set_on(led2);
try gpio.set_off(act);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
try gpio.set_off(led0);
try gpio.set_off(led1);
try gpio.set_off(led2);
try gpio.set_on(act);
- util.delay_cycles(1000000);
+ delay_cycles(1000000);
}
try gpio.set_on(act);
diff --git a/src/util.zig b/src/util.zig
@@ -1,11 +0,0 @@
-pub extern fn nop() void;
-pub extern fn get_u32(address: *u32) u32;
-pub extern fn put_u32(address: *u32, value: u32) void;
-
-pub noinline fn delay_cycles(ticks: usize) void {
- var counter = ticks;
- while (counter > 0) {
- counter -= 1;
- nop(); // Prevent optimization
- }
-}
