sylveos

commit bec24b32e7ba98c90eb70f25af83d5a11b184fb9
parent 18e68acfdd9b4d9ca827c37836aa5363b9553e39
Author: Sylvia Ivory <git@sivory.net>
Date:   Tue, 13 Jan 2026 15:55:10 -0800

Adjust build settings

Diffstat:
M
Justfile
 | 
4
++--
M
build.zig
 | 
9
+++++----
M
linker.ld
 | 
2
++
M
src/root.zig
 | 
10
+++-------

4 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/Justfile b/Justfile
@@ -4,5 +4,5 @@ build:
 lab name:
     zig build -Dlab={{ name }}
 
-list: build
-    arm-none-eabi-objdump -D zig-out/bin/SylveOS
+list name="SylveOS": build
+    arm-none-eabi-objdump -m armv6 -d zig-out/bin/{{ name }}
diff --git a/build.zig b/build.zig
@@ -10,6 +10,7 @@ const target: std.Target.Query = .{
     .cpu_model = .{ .explicit = &std.Target.arm.cpu.arm1176jzf_s },
     .cpu_features_add = std.Target.arm.cpu.arm1176jzf_s.features,
     .os_tag = .freestanding,
+    .abi = .none,
 };
 
 fn add_exe(exe_name: []const u8, path: std.Build.LazyPath, b: *std.Build) !*std.Build.Step.Compile {
@@ -50,14 +51,14 @@ fn lab(name: []const u8, units: []const []const u8, b: *std.Build) !void {
 
         const template =
             \\ const lab = @import("{s}");
-            \\ export fn main() void {{ lab.{s}(); }}
-            \\ export fn abort() void {{ while(true) {{}} }}
             \\ export fn _start() callconv(.naked) noreturn {{
             \\     asm volatile (
             \\        \\ mov sp, 0x800000
-            \\        \\ bl main
-            \\        \\ bl abort
+            \\        \\ bl %[main:P]
+            \\        :
+            \\        : [main] "X" (&lab.{s})
             \\     );
+            \\     while (true) {{ }}
             \\ }}
         ;
 
diff --git a/linker.ld b/linker.ld
@@ -7,6 +7,8 @@
  * pi-install bootloader will copy the program it receives
  * to address 0x8000 and jump to it.
  */
+ENTRY(_start)
+
 SECTIONS
 {
     /* link the code first at 0x8000. */
diff --git a/src/root.zig b/src/root.zig
@@ -14,16 +14,12 @@ fn panic_handler(msg: []const u8, trace_addr: ?usize) noreturn {
 
 pub const panic = std.debug.FullPanic(panic_handler);
 
-// Can't just use main.zig#main directly
-export fn main() void {
-    _ = fake_main();
-}
-
 export fn _start() callconv(.naked) noreturn {
-    // TODO; ask prof why
     asm volatile (
         \\ mov sp, 0x800000
-        \\ bl main
+        \\ bl %[main:P]
         \\ bl abort
+        :
+        : [main] "X" (&fake_main),
     );
 }