basic executable loading

7 files changed, 52 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index 3df2ac7..b6eaf0a 100644
--- a/Makefile
+++ b/Makefile
@@ -21,9 +21,9 @@ out/fs/boot/kernel.bin: src/kernel/linker.ld $(call from_sources, src/kernel/)
 	$(CC) $(LFLAGS) -T $^ -o $@
 	grub-file --is-x86-multiboot $@
 
-out/fs/boot/init: src/test_module
+out/fs/boot/init: src/init/linker.ld $(call from_sources, src/init/)
 	@mkdir -p $(@D)
-	@cp $< $@
+	$(CC) $(LFLAGS) -T $^ -o $@
 
 out/fs/boot/grub/grub.cfg: grub.cfg
 	@mkdir -p $(@D)
diff --git a/src/init/linker.ld b/src/init/linker.ld
new file mode 100644
index 0000000..9f3f4b5
--- /dev/null
+++ b/src/init/linker.ld
@@ -0,0 +1,24 @@
+ENTRY(main)
+OUTPUT_FORMAT("binary")
+
+SECTIONS
+{
+	. = 2M;
+	.text BLOCK(4K) : ALIGN(4K)
+	{
+		*(.text)
+	}
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+	.data BLOCK(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+	.bss BLOCK(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+	}
+}
diff --git a/src/init/main.c b/src/init/main.c
new file mode 100644
index 0000000..e6188ac
--- /dev/null
+++ b/src/init/main.c
@@ -0,0 +1,10 @@
+#include <stdint.h>
+
+int main() {
+	// change the colors of VGA text
+	// doesn't require a lot of code, but still shows that it's working
+	uint8_t *vga = (void*) 0xB8000;
+	for (int i = 0; i < 80 * 25; i++)
+		vga[(i << 1) + 1] = 0x4e;
+	for (;;);
+}
diff --git a/src/kernel/main.c b/src/kernel/main.c
index 677faaf..7f49fed 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -3,16 +3,21 @@
 #include <kernel/mem.h>
 #include <kernel/panic.h>
 #include <kernel/proc.h>
+#include <kernel/util.h>
+#include <stdint.h>
 
 void r3_test();
 
 void kmain(struct kmain_info info) {
-	log_write(info.init.at, info.init.size);
 	log_const("mem...");
 	mem_init(&info);
 
 	log_const("creating process...");
-	struct process *proc = process_new(r3_test);
+
+	void *init_addr = (void*)0x200000;
+	memcpy(init_addr, info.init.at, info.init.size);
+
+	struct process *proc = process_new(init_addr);
 	log_const("switching...");
 	process_switch(proc);
 }
diff --git a/src/kernel/util.c b/src/kernel/util.c
index da3ac9d..f4dc5e1 100644
--- a/src/kernel/util.c
+++ b/src/kernel/util.c
@@ -1,6 +1,14 @@
 #include <kernel/util.h>
 #include <stdint.h>
 
+void *memcpy(void *dest, const void *src, size_t n) {
+	char *d = dest;
+	const char *s = src;
+	for (size_t i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
 void *memset(void *s, int c, size_t n) {
 	uint8_t *s2 = s;
 	for (size_t i = 0; i < n; n++)
diff --git a/src/kernel/util.h b/src/kernel/util.h
index 688ac63..4bd7c31 100644
--- a/src/kernel/util.h
+++ b/src/kernel/util.h
@@ -1,4 +1,5 @@
 #pragma once
 #include <stddef.h>
 
+void *memcpy(void *dest, const void *src, size_t n);
 void *memset(void *s, int c, size_t n);
diff --git a/src/test_module b/src/test_module
deleted file mode 100644
index 4e809fd..0000000
--- a/src/test_module
+++ /dev/null
@@ -1 +0,0 @@
-[init binary goes here]