From 5d73ba1059771f3226c1f45d41a9e3f52d68ee3d Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Mon, 15 Sep 2025 15:51:13 -0400
Subject: begin init staging refactor

---
 apps/init/stage1/initrd.h         |  5 +++++
 apps/init/stage1/kprint.c         | 15 +++++++++++++++
 apps/init/stage1/kprint.h         |  7 +++++++
 apps/init/stage1/main.c           | 24 ++++++++++++++++++++++++
 apps/init/stage1/memory.h         |  6 ++++++
 apps/init/stage1/stage1.h         | 12 ++++++++++++
 apps/init/stage1/x86_64/syscall.c | 19 +++++++++++++++++++
 7 files changed, 88 insertions(+)
 create mode 100644 apps/init/stage1/initrd.h
 create mode 100644 apps/init/stage1/kprint.c
 create mode 100644 apps/init/stage1/kprint.h
 create mode 100644 apps/init/stage1/main.c
 create mode 100644 apps/init/stage1/memory.h
 create mode 100644 apps/init/stage1/stage1.h
 create mode 100644 apps/init/stage1/x86_64/syscall.c

(limited to 'apps/init/stage1')

diff --git a/apps/init/stage1/initrd.h b/apps/init/stage1/initrd.h
new file mode 100644
index 0000000..b4bec79
--- /dev/null
+++ b/apps/init/stage1/initrd.h
@@ -0,0 +1,5 @@
+#ifndef INIT_STAGE1_INITRD_H
+#define INIT_STAGE1_INITRD_H 1
+
+
+#endif
diff --git a/apps/init/stage1/kprint.c b/apps/init/stage1/kprint.c
new file mode 100644
index 0000000..57e10f5
--- /dev/null
+++ b/apps/init/stage1/kprint.c
@@ -0,0 +1,15 @@
+#include "stage1.h"
+#include <kernel/syscall.h>
+
+void
+kputc(char c)
+{
+    _syscall_payload[0] = c;
+    syscall_invoke_noret(SYSCALL_DEBUG_PUTC);
+}
+
+void
+kputs(const char *s)
+{
+    for(; *s; s++) kputc(*s);
+}
diff --git a/apps/init/stage1/kprint.h b/apps/init/stage1/kprint.h
new file mode 100644
index 0000000..ea71012
--- /dev/null
+++ b/apps/init/stage1/kprint.h
@@ -0,0 +1,7 @@
+#ifndef INIT_STAGE1_KPRINT_H
+#define INIT_STAGE1_KPRINT_H 1
+
+void kputc(char c);
+void kputs(const char *s);
+
+#endif
diff --git a/apps/init/stage1/main.c b/apps/init/stage1/main.c
new file mode 100644
index 0000000..90e663d
--- /dev/null
+++ b/apps/init/stage1/main.c
@@ -0,0 +1,24 @@
+#include "stage1.h"
+#include "kprint.h"
+#include <kernel/init.h>
+
+uint8_t *_syscall_payload;
+uint8_t  _syscall_message;
+
+void main(void *init_message_ptr)
+{
+    _syscall_payload = init_message_ptr;
+    _syscall_message = INIT_OBJECT_MESSAGE;
+
+    kputs("Hello, Userland!\n");
+    for(;;);
+}
+
+__attribute__((naked))
+void
+_start(void)
+{
+    __asm__ volatile("\
+            popq %rdi; \
+            jmp main");
+}
diff --git a/apps/init/stage1/memory.h b/apps/init/stage1/memory.h
new file mode 100644
index 0000000..72db624
--- /dev/null
+++ b/apps/init/stage1/memory.h
@@ -0,0 +1,6 @@
+#ifndef INIT_STAGE1_MEMORY_H
+#define INIT_STAGE1_MEMORY_H 1
+
+
+
+#endif
diff --git a/apps/init/stage1/stage1.h b/apps/init/stage1/stage1.h
new file mode 100644
index 0000000..d6c3e90
--- /dev/null
+++ b/apps/init/stage1/stage1.h
@@ -0,0 +1,12 @@
+#ifndef INIT_STAGE1_H
+#define INIT_STAGE1_H 1
+
+#include <stdint.h>
+
+extern uint8_t *_syscall_payload;
+extern uint8_t  _syscall_message;
+
+void syscall_invoke_noret(uint64_t calltype);
+intmax_t syscall_invoke_ret(uint64_t calltype);
+
+#endif
diff --git a/apps/init/stage1/x86_64/syscall.c b/apps/init/stage1/x86_64/syscall.c
new file mode 100644
index 0000000..d63be52
--- /dev/null
+++ b/apps/init/stage1/x86_64/syscall.c
@@ -0,0 +1,19 @@
+#include "stage1/stage1.h"
+
+void 
+syscall_invoke_noret(uint64_t calltype)
+{
+    __asm__ volatile("syscall":: "S"(calltype), "D"(_syscall_message): "memory");
+}
+
+int64_t 
+syscall_invoke_ret(uint64_t calltype)
+{
+    int rax = 0; \
+    __asm__ volatile("syscall": "=a"(rax) \
+                              : "S"(calltype), "D"(_syscall_message) \
+                              : "memory");
+    return rax;
+
+}
+
-- 
cgit v1.2.1