From a8b2282eb88f24c3c5f461e1557fa2cf76ebc251 Mon Sep 17 00:00:00 2001
From: turret <turret@duck.com>
Date: Sun, 19 Nov 2023 18:57:55 -0600
Subject: Initial commit

- create subsystem system using clone syscall, shared memory, shared
  file descriptors
- printk-like logging facility (TODO: console loglevel)
- initcall system (like linux kernel)

TODO: determine license
factors: linker.ld, linux kernel licensing (some ideas are more
  liberally taken rather than paraphrased)
---
 init/init.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 init/init.c

(limited to 'init/init.c')

diff --git a/init/init.c b/init/init.c
new file mode 100644
index 0000000..5363082
--- /dev/null
+++ b/init/init.c
@@ -0,0 +1,60 @@
+#include <signal.h>
+#include <sys/wait.h>
+
+#include <init.h>
+#include <util.h>
+
+/* For some reason, I get SIGSEGV'd when running because a random-ass
+   byte was inserted where it isnt supposed to be. Added a safety byte
+   because I cannot be asked to try to figure out how to do this cleanly. */
+static unsigned long __1bsafebuf
+    __attribute__((used)) __attribute__((section(".1bsafebuf.init"))) = 0;
+
+extern initcall_entry_t __initcall1_start[];
+extern initcall_entry_t __initcall2_start[];
+extern initcall_entry_t __initcall3_start[];
+extern initcall_entry_t __initcall4_start[];
+extern initcall_entry_t __initcall5_start[];
+extern initcall_entry_t __initcall_end[];
+
+static initcall_entry_t *initcall_levels[] = {
+    __initcall1_start,
+    __initcall2_start,
+    __initcall3_start,
+    __initcall4_start,
+    __initcall5_start,
+    __initcall_end,
+};
+
+static void do_initcall_level(int level)
+{
+    initcall_entry_t *fn;
+
+    for (fn = initcall_levels[level - 1]; fn < initcall_levels[level]; fn++)
+        initcall_from_entry(fn)();
+}
+
+static void do_initcalls(void)
+{
+    unsigned long level;
+    for (level = 1; level < ARRAY_SIZE(initcall_levels); level++) {
+        do_initcall_level(level);
+    }
+}
+
+int main(void)
+{
+    do_initcalls();
+
+    static sigset_t set;
+    sigaddset(&set, SIGCHLD);
+    sigprocmask(SIG_BLOCK, &set, NULL);
+
+    while(1) {
+        int sig;
+        sigwait(&set, &sig);
+        if(sig == SIGCHLD)
+            while(waitpid(0, NULL, WNOHANG) > 0)
+                ;
+    }
+}
-- 
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