97 lines
2.7 KiB
Zig
97 lines
2.7 KiB
Zig
// Markus Maiwald (Architect) | Voxis Forge (AI)
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// RUMPK L0
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// libc_stubs.zig
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// We are the standard library now.
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const uart = @import("uart.zig");
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// =========================================================
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// Heap Stubs (Bump Allocator with Block Headers)
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// =========================================================
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// Simple Bump Allocator for L0
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var heap: [8 * 1024 * 1024]u8 align(4096) = undefined; // 8MB Heap
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var heap_idx: usize = 0;
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// Header structure (64 bytes aligned to match LwIP MEM_ALIGNMENT)
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const BlockHeader = struct {
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size: usize,
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_pad: [64 - @sizeOf(usize)]u8,
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};
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export fn malloc(size: usize) ?*anyopaque {
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if (size == 0) return null;
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const total_needed = size + @sizeOf(BlockHeader);
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const align_mask: usize = 63; // 64-byte alignment
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const aligned_idx = (heap_idx + align_mask) & ~align_mask;
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if (aligned_idx + total_needed > heap.len) {
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return null;
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}
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const base_ptr = &heap[aligned_idx];
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const header = @as(*BlockHeader, @ptrCast(@alignCast(base_ptr)));
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header.size = size;
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heap_idx = aligned_idx + total_needed;
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return @as(*anyopaque, @ptrFromInt(@intFromPtr(base_ptr) + @sizeOf(BlockHeader)));
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}
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export fn free(ptr: ?*anyopaque) void {
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// Bump allocator: no-op free.
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_ = ptr;
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}
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export fn realloc(ptr: ?*anyopaque, size: usize) ?*anyopaque {
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if (ptr == null) return malloc(size);
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if (size == 0) {
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free(ptr);
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return null;
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}
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// Retrieve old size from header
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const base_addr = @intFromPtr(ptr.?) - @sizeOf(BlockHeader);
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const header = @as(*BlockHeader, @ptrFromInt(base_addr));
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const old_size = header.size;
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// Optimization: If new size is smaller and it's the last block, we could shrink?
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// But for a bump allocator, just allocate new.
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const new_ptr = malloc(size);
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if (new_ptr) |np| {
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const copy_size = if (size < old_size) size else old_size;
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const src = @as([*]const u8, @ptrCast(ptr.?));
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const dst = @as([*]u8, @ptrCast(np));
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var i: usize = 0;
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while (i < copy_size) : (i += 1) {
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dst[i] = src[i];
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}
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free(ptr);
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return np;
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}
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return null;
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}
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export fn calloc(nmemb: usize, size: usize) ?*anyopaque {
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const total = nmemb * size;
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const ptr = malloc(total);
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if (ptr) |p| {
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const dst = @as([*]u8, @ptrCast(p));
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var i: usize = 0;
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while (i < total) : (i += 1) {
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dst[i] = 0;
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}
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}
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return ptr;
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}
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// =========================================================
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// Rumpk Runtime Support
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// =========================================================
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export fn get_ticks() u32 {
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return 0; // TODO: Implement real timer
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}
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