zba-gdbstub/src/lib.zig

149 lines
4.3 KiB
Zig

const std = @import("std");
const Allocator = std.mem.Allocator;
/// Re-export of the server interface
pub const Server = @import("Server.zig");
const State = @import("State.zig");
/// Interface for interacting between GDB and a GBA emu
pub const Emulator = struct {
const Self = @This();
const Signal = union(enum) {
const Kind = enum { HwBkpt, SwBkpt };
Trap: Kind,
SingleStep: void,
};
state: State,
ptr: *anyopaque,
readFn: *const fn (*anyopaque, u32) u8,
writeFn: *const fn (*anyopaque, u32, u8) void,
registersFn: *const fn (*anyopaque) *[16]u32,
cpsrFn: *const fn (*anyopaque) u32,
stepFn: *const fn (*anyopaque) void,
pub fn init(allocator: Allocator, ptr: anytype) Self {
const Ptr = @TypeOf(ptr);
const ptr_info = @typeInfo(Ptr);
if (ptr_info != .Pointer) @compileError("ptr must be a pointer");
if (ptr_info.Pointer.size != .One) @compileError("ptr must be a single-item pointer");
const gen = struct {
pub fn readImpl(pointer: *anyopaque, addr: u32) u8 {
const self: Ptr = @ptrCast(@alignCast(pointer));
return @call(.always_inline, ptr_info.Pointer.child.read, .{ self, addr });
}
pub fn writeImpl(pointer: *anyopaque, addr: u32, value: u8) void {
const self: Ptr = @ptrCast(@alignCast(pointer));
return @call(.always_inline, ptr_info.Pointer.child.write, .{ self, addr, value });
}
pub fn registersImpl(pointer: *anyopaque) *[16]u32 {
const self: Ptr = @ptrCast(@alignCast(pointer));
return @call(.always_inline, ptr_info.Pointer.child.registers, .{self});
}
pub fn cpsrImpl(pointer: *anyopaque) u32 {
const self: Ptr = @ptrCast(@alignCast(pointer));
return @call(.always_inline, ptr_info.Pointer.child.cpsr, .{self});
}
pub fn stepImpl(pointer: *anyopaque) void {
const self: Ptr = @ptrCast(@alignCast(pointer));
return @call(.always_inline, ptr_info.Pointer.child.step, .{self});
}
};
return .{
.ptr = ptr,
.readFn = gen.readImpl,
.writeFn = gen.writeImpl,
.registersFn = gen.registersImpl,
.cpsrFn = gen.cpsrImpl,
.stepFn = gen.stepImpl,
.state = State.init(allocator),
};
}
pub fn deinit(self: *Self) void {
self.state.deinit();
self.* = undefined;
}
pub inline fn read(self: Self, addr: u32) u8 {
return self.readFn(self.ptr, addr);
}
pub inline fn write(self: Self, addr: u32, value: u8) void {
self.writeFn(self.ptr, addr, value);
}
pub inline fn registers(self: Self) *[16]u32 {
return self.registersFn(self.ptr);
}
pub inline fn cpsr(self: Self) u32 {
return self.cpsrFn(self.ptr);
}
pub inline fn contd(self: *Self) Signal {
while (true) {
const signal = self.step();
switch (signal) {
.SingleStep => {},
.Trap => return signal,
}
}
}
pub inline fn step(self: *Self) Signal {
self.stepFn(self.ptr);
const r = self.registersFn(self.ptr);
const is_thumb = self.cpsrFn(self.ptr) >> 5 & 1 == 1;
const r15 = r[15] -| if (is_thumb) @as(u32, 4) else 8;
if (self.state.sw_bkpt.isHit(r15)) return .{ .Trap = .SwBkpt };
if (self.state.hw_bkpt.isHit(r15)) return .{ .Trap = .HwBkpt };
return .SingleStep;
}
const BkptType = enum { Hardware, Software };
// TODO: Consider properly implementing Software interrupts?
pub fn addBkpt(self: *Self, comptime @"type": BkptType, addr: u32, kind: u32) !void {
switch (@"type") {
.Hardware => try self.state.hw_bkpt.add(addr, kind),
.Software => try self.state.sw_bkpt.add(addr, kind),
}
}
pub fn removeBkpt(self: *Self, comptime @"type": BkptType, addr: u32) void {
switch (@"type") {
.Hardware => self.state.hw_bkpt.remove(addr),
.Software => self.state.sw_bkpt.remove(addr),
}
}
};
test {
_ = @import("test.zig");
}