From d1ff7bcc91886626dc9060ec5fb67ee102ab7c1d Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Mon, 11 Mar 2024 21:30:31 -0400
Subject: usermode capable kernel with logging syscall

---
 usr/elf.h     | 12 ++++++++++++
 usr/syscall.c | 23 +++++++++++++++++++++++
 usr/syscall.d |  2 ++
 usr/syscall.h | 10 ++++++++++
 usr/umode.c   | 31 +++++++++++++++++++++++++++++++
 usr/umode.d   |  3 +++
 usr/umode.h   |  8 ++++++++
 7 files changed, 89 insertions(+)
 create mode 100644 usr/elf.h
 create mode 100644 usr/syscall.c
 create mode 100644 usr/syscall.d
 create mode 100644 usr/syscall.h
 create mode 100644 usr/umode.c
 create mode 100644 usr/umode.d
 create mode 100644 usr/umode.h

(limited to 'usr')

diff --git a/usr/elf.h b/usr/elf.h
new file mode 100644
index 0000000..d805e55
--- /dev/null
+++ b/usr/elf.h
@@ -0,0 +1,12 @@
+#ifndef JOVE_USER_ELF_H
+#define JOVE_USER_ELF_H 1
+
+#include <stddef.h>
+
+/**Load an ELF file into usermode memory.
+ * @param data pointer to ELF file data buffer
+ * @param len length of ELF file data buffer
+ * @return entry point for loaded ELF exec*/
+void *elf_load(const void *data, size_t len);
+
+#endif
diff --git a/usr/syscall.c b/usr/syscall.c
new file mode 100644
index 0000000..0ea5700
--- /dev/null
+++ b/usr/syscall.c
@@ -0,0 +1,23 @@
+#include "syscall.h"
+#include "mem/memory.h"
+#include "io/log.h"
+
+int _syscall_handler_log(struct syscall_log *req)
+{
+    klogf("Message ptr %#016X\n", req->message);
+    if(!mem_check_ptr(req->message)) return -1;
+    klogf("%s", req->message);
+    return 0;
+}
+
+void *_syscall_handlers[SYSCALL_COUNT] = {
+    _syscall_handler_log
+};
+
+int
+syscall_handler(syscall_t *req)
+{
+    if(!mem_check_ptr(req)) return -1;
+    if(req->id >= SYSCALL_COUNT) return -1;
+    return ((syscall_handler_t)(_syscall_handlers[req->id]))(req);
+}
diff --git a/usr/syscall.d b/usr/syscall.d
new file mode 100644
index 0000000..9d5acbf
--- /dev/null
+++ b/usr/syscall.d
@@ -0,0 +1,2 @@
+usr/syscall.o: usr/syscall.c usr/syscall.h abi/syscall.h mem/memory.h \
+ mem/slab.h io/log.h
diff --git a/usr/syscall.h b/usr/syscall.h
new file mode 100644
index 0000000..49beb85
--- /dev/null
+++ b/usr/syscall.h
@@ -0,0 +1,10 @@
+#ifndef JOVE_USER_SYSCALL_H
+#define JOVE_USER_SYSCALL_H 1
+
+#include "abi/syscall.h"
+
+typedef int (*syscall_handler_t)(syscall_t*);
+
+int _syscall_handler_log(struct syscall_log *req);
+
+#endif
diff --git a/usr/umode.c b/usr/umode.c
new file mode 100644
index 0000000..4ef5306
--- /dev/null
+++ b/usr/umode.c
@@ -0,0 +1,31 @@
+#include "umode.h"
+#include "elf.h"
+#include "boot/cmdline.h"
+#include "lib/jove.h"
+#include "ird/initrd.h"
+#include "mem/memory.h"
+
+void
+umode_setup(void)
+{
+    extern void syscall_setup_syscall(void);
+    syscall_setup_syscall();
+
+    const char *init_path = cmdline_get("init");
+    if(init_path == NULL)
+        kpanic("Missing path to init ELF file / binary\n");
+
+    struct InitrdFile *init_file = ird_getfile(init_path);
+    if(init_file == NULL)
+        kpanic("Missing init file %s in initrd\n", init_path);
+
+    void (*entry_point)(void) = elf_load(init_file->data, init_file->size);
+    if(entry_point == NULL)
+        kpanic("Init file %s is incorrectly formatted (want ELF64)\n", init_path);
+
+    void *user_stack = (void*)(0x00007FFFFFFFFFFF);
+    mem_ensure_range((uintptr_t)user_stack & ~0xFFF, (uintptr_t)user_stack, true, true);
+
+    klogf("User entry point %#016X\n", entry_point);
+    umode_enter(entry_point, user_stack);
+}
diff --git a/usr/umode.d b/usr/umode.d
new file mode 100644
index 0000000..54c004b
--- /dev/null
+++ b/usr/umode.d
@@ -0,0 +1,3 @@
+usr/umode.o: usr/umode.c usr/umode.h usr/elf.h boot/cmdline.h \
+ lib/hashtable.h lib/linkedlist.h lib/jove.h ird/initrd.h ird/tar.h \
+ lib/linkedlist.h mem/memory.h mem/slab.h
diff --git a/usr/umode.h b/usr/umode.h
new file mode 100644
index 0000000..2755abe
--- /dev/null
+++ b/usr/umode.h
@@ -0,0 +1,8 @@
+#ifndef JOVE_UMODE_H
+#define JOVE_UMODE_H 1
+
+void umode_setup(void);
+
+void umode_enter(void (*entry)(void), void *stack);
+
+#endif
-- 
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