feat: load + run native ELF binaries

2 files changed, 30 insertions, 0 deletions

diff --git a/user/link.ld b/user/link.ld
new file mode 100644
index 0000000..9dc8402
--- /dev/null
+++ b/user/link.ld
@@ -0,0 +1,8 @@
+ENTRY(_start)
+SECTIONS {
+    . = 0x400000;
+    .text   : ALIGN(0x1000) { *(.text*) }
+    .rodata : ALIGN(0x1000) { *(.rodata*) }
+    .data   : ALIGN(0x1000) { *(.data*) }
+    .bss    : ALIGN(0x1000) { *(.bss*) *(COMMON) }
+}
diff --git a/user/program.c b/user/program.c
new file mode 100644
index 0000000..8e26128
--- /dev/null
+++ b/user/program.c
@@ -0,0 +1,22 @@
+static long sys_write(const char* buffer, unsigned long buffer_size)
+{
+    long ret;
+    __asm__ volatile("int $0x80" : "=a"(ret) : "a"(1L), "D"(buffer), "S"(buffer_size) : "memory");
+    return ret;
+}
+static void sys_exit(long code)
+{
+    __asm__ volatile("int $0x80" : : "a"(0L), "D"(code) : "memory");
+    for (;;);
+}
+
+void _start(void)
+{
+    const char* message = "wassup shawty\n";
+    unsigned long message_length = 0;
+    while (message[message_length])
+        message_length++;
+
+    sys_write(message, message_length);
+    sys_exit(0);
+}