From a10aabfcd52f702057316018cd7847ab2bfe4aa1 Mon Sep 17 00:00:00 2001
From: Ada Christine <adachristine18@gmail.com>
Date: Tue, 26 May 2026 21:32:27 +0000
Subject: we're bringing kjarna back and not doing the crazy stuff with trying
 to have task management during efi. that was a bit extra.

---
 kc/core/cpu/arch_thread.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 kc/core/cpu/arch_thread.c

(limited to 'kc/core/cpu/arch_thread.c')

diff --git a/kc/core/cpu/arch_thread.c b/kc/core/cpu/arch_thread.c
new file mode 100644
index 0000000..c0d707a
--- /dev/null
+++ b/kc/core/cpu/arch_thread.c
@@ -0,0 +1,81 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <stdnoreturn.h>
+
+#include <libc/stdio.h>
+
+#include "task.h"
+
+struct arch_register_context
+{
+	uint64_t
+		r15,
+		r14,
+		r13,
+		r12,
+		r11,
+		r10,
+		r9,
+		r8,
+		rsi,
+		rdi,
+		rdx,
+		rcx,
+		rbx,
+		rax,
+		rbp,
+		rsp;
+};
+
+extern uint64_t *get_tss_rsp0(void);
+
+struct arch_thread_context
+{
+	struct arch_register_context register_context;
+	void *return_address;
+};
+
+extern void arch_swap_thread_stack(
+		void * volatile *outgoing_stack,
+		void *incoming_stack);
+
+extern void arch_begin_thread(
+		void *(func)(void *),
+		void *params);
+
+void arch_create_thread(
+		struct kc_thread *thread,
+		void *(*func)(void *),
+		void *params)
+{
+	uintptr_t stack_pointer = (uintptr_t)thread->kernel_stack_pointer;
+	struct arch_thread_context *context = (struct arch_thread_context *)
+		(stack_pointer -= sizeof(*context));
+	thread->kernel_stack_pointer = (void *)stack_pointer;
+
+	context->return_address = (void *)arch_begin_thread;
+	context->register_context.rdi = (uint64_t)func;
+	context->register_context.rsi = (uint64_t)params;
+	context->register_context.rdx = (uint64_t)thread;
+	context->register_context.rsp = (uint64_t)&context->return_address;
+}
+
+void arch_swap_thread(
+		struct kc_thread *outgoing,
+		struct kc_thread *incoming)
+{
+	arch_swap_thread_stack(&outgoing->kernel_stack_pointer, incoming->kernel_stack_pointer);
+}
+
+void *arch_idle_loop(void *)
+{
+	for (;;) __asm__ ("hlt");
+	return nullptr;
+}
+
+noreturn void arch_terminate_thread(union kc_thread_result result, struct kc_thread *)
+{
+	kct_terminate(result);
+	for (;;) __asm__ ("hlt");
+}
+
-- 
cgit v1.3.1-1-g115d