amd64: barely boot into kernel code

1 files changed, 61 insertions, 0 deletions

diff --git a/src/kernel/arch/amd64/driver/ps2.c b/src/kernel/arch/amd64/driver/ps2.c
new file mode 100644
index 0000000..8a5a078
--- /dev/null
+++ b/src/kernel/arch/amd64/driver/ps2.c
@@ -0,0 +1,61 @@
+#include <kernel/arch/amd64/driver/ps2.h>
+#include <kernel/arch/amd64/interrupts/irq.h>
+#include <kernel/mem/virt.h>
+#include <kernel/panic.h>
+#include <kernel/vfs/request.h>
+#include <shared/container/ring.h>
+#include <shared/mem.h>
+
+#define BACKLOG_CAPACITY 64
+static volatile uint8_t backlog_buf[BACKLOG_CAPACITY];
+static volatile ring_t backlog = {(void*)backlog_buf, BACKLOG_CAPACITY, 0, 0};
+
+static void accept(struct vfs_request *req);
+static bool is_ready(struct vfs_backend *self);
+
+static struct vfs_request *blocked_on = NULL;
+static struct vfs_backend backend = BACKEND_KERN(is_ready, accept);
+void ps2_init(void) { vfs_mount_root_register("/ps2", &backend); }
+
+
+void ps2_recv(uint8_t s) {
+	ring_put1b((void*)&backlog, s);
+	if (blocked_on) {
+		accept(blocked_on);
+		blocked_on = NULL;
+		vfs_backend_tryaccept(&backend);
+	}
+}
+
+static void accept(struct vfs_request *req) {
+	// when you fix something here go also fix it in the COM1 driver
+	static uint8_t buf[32]; // pretty damn stupid
+	int ret;
+	bool valid;
+	switch (req->type) {
+		case VFSOP_OPEN:
+			valid = req->input.len == 0;
+			vfsreq_finish_short(req, valid ? 0 : -1);
+			break;
+		case VFSOP_READ:
+			if (ring_size((void*)&backlog) == 0) {
+				// nothing to read
+				blocked_on = req;
+			} else if (req->caller) {
+				ret = clamp(0, req->output.len, sizeof buf);
+				ret = ring_get((void*)&backlog, buf, ret);
+				virt_cpy_to(req->caller->pages, req->output.buf, buf, ret);
+				vfsreq_finish_short(req, ret);
+			} else {
+				vfsreq_finish_short(req, -1);
+			}
+			break;
+		default:
+			vfsreq_finish_short(req, -1);
+			break;
+	}
+}
+
+static bool is_ready(struct vfs_backend __attribute__((unused)) *self) {
+	return blocked_on == NULL;
+}