sylveos

commit 5489ba5ae05dc12e6c7056b73c35d8e3050a2d93
parent 93f89d83bb17f5f5dbdb2f184f4c60d0861c88fd
Author: Sylvia Ivory <git@sivory.net>
Date:   Sun,  8 Mar 2026 20:58:10 -0700

Add SD card module

Diffstat:
A
pi/devices/sd.zig
 | 
37
+++++++++++++++++++++++++++++++++++++
M
pi/root.zig
 | 
1
+

2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/pi/devices/sd.zig b/pi/devices/sd.zig
@@ -0,0 +1,37 @@
+// Temporarily use external C code until I feel like writing my own
+const std = @import("std");
+const pi_sd = @cImport({
+    @cInclude("pi-sd.h");
+});
+
+const Self = @This();
+
+alloc: std.mem.Allocator,
+
+pub fn init(alloc: std.mem.Allocator) Self {
+    return .{ .alloc = alloc };
+}
+
+pub fn read_sector(self: *const Self, sector: usize) !u4096 {
+    _ = self;
+
+    var buffer: [512]u8 = .{0} ** 512;
+    if (pi_sd.pi_sd_read(&buffer, sector, 1) == -1) {
+        return error.InvalidRead;
+    }
+
+    return std.mem.readInt(u4096, buffer[0..512], .little);
+}
+
+pub fn read_sectors(self: *const Self, sector: usize, count: usize) ![]u4096 {
+    var buffer = try self.alloc.alloc(u8, count * 512);
+    if (pi_sd.pi_sd_read(&buffer, sector, 1) == -1) {
+        return error.InvalidRead;
+    }
+
+    return @ptrCast(@alignCast(buffer));
+}
+
+pub fn free_sectors(self: *const Self, sectors: []u4096) void {
+    self.alloc.free(sectors);
+}
diff --git a/pi/root.zig b/pi/root.zig
@@ -23,6 +23,7 @@ pub const devices = struct {
     pub const sw_uart = @import("./devices/sw-uart.zig");
     pub const timer = @import("./devices/timer.zig");
     pub const mailbox = @import("./devices/mailbox.zig");
+    pub const sd = @import("./devices/sd.zig");
 };
 
 pub export const STACK_ADDRESS: usize = 0x8000000;