From 793fbcd03cc830f09746e8d96b70cd17f41b4a69 Mon Sep 17 00:00:00 2001
From: Thomas Oltmann <thomas.oltmann.hhg@gmail.com>
Date: Fri, 4 Jul 2025 03:10:55 +0200
Subject: [PATCH] First sign of life

---
 .gitignore        |  5 +++++
 Makefile          | 21 +++++++++++++++++++++
 Readme.md         |  2 ++
 boot16.S          | 14 ++++++++++++++
 config.default.mk |  5 +++++
 fernlader.ld      |  6 ++++++
 run-qemu.sh       |  2 ++
 7 files changed, 55 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 Readme.md
 create mode 100644 boot16.S
 create mode 100644 config.default.mk
 create mode 100644 fernlader.ld
 create mode 100755 run-qemu.sh

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..7f5d9c3
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+config.mk
+
+*.o
+boot.bin
+boot.elf
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b953e39
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,21 @@
+-include config.mk
+
+.PHONY: all clean
+
+all: boot.bin
+
+clean:
+	rm -f *.o
+	rm -f boot.elf boot.bin
+
+config.mk: | config.default.mk
+	cp config.default.mk $@
+
+boot.bin: boot.elf
+	objcopy -O binary --only-section=.text boot.elf $@
+
+boot.elf: boot16.o fernlader.ld
+	$(LD) $(LDFLAGS) -o $@ boot16.o
+
+.S.o:
+	$(CC) $(CFLAGS) -c -o $@ $(@:.o=.S)
diff --git a/Readme.md b/Readme.md
new file mode 100644
index 0000000..2110f08
--- /dev/null
+++ b/Readme.md
@@ -0,0 +1,2 @@
+# fernlader -- bootboot-compliant PXE bootloader
+
diff --git a/boot16.S b/boot16.S
new file mode 100644
index 0000000..e5ac141
--- /dev/null
+++ b/boot16.S
@@ -0,0 +1,14 @@
+            // vim: et:sw=12:ts=12:sts=12
+
+            .code16
+            .global     _start
+            .text
+
+_start:
+            xor         %bx, %bx
+            mov         $0x0E, %ah
+            mov         $'A', %al
+            int         $0x10
+
+1:          hlt
+            jmp         1b
diff --git a/config.default.mk b/config.default.mk
new file mode 100644
index 0000000..576b634
--- /dev/null
+++ b/config.default.mk
@@ -0,0 +1,5 @@
+CC = cc
+LD = ld
+
+CFLAGS = -no-pie -fno-pic
+LDFLAGS = -Tfernlader.ld
diff --git a/fernlader.ld b/fernlader.ld
new file mode 100644
index 0000000..989ace6
--- /dev/null
+++ b/fernlader.ld
@@ -0,0 +1,6 @@
+SECTIONS {
+    . = 0x7C00;
+    .text : {
+        *(*)
+    }
+}
diff --git a/run-qemu.sh b/run-qemu.sh
new file mode 100755
index 0000000..0cc4dc7
--- /dev/null
+++ b/run-qemu.sh
@@ -0,0 +1,2 @@
+#!/bin/sh
+qemu-system-x86_64 -netdev user,id=n1,net=10.0.0.5/24,tftp=netboot,bootfile=/boot.bin -device virtio-net-pci,netdev=n1