From f092bf03baf3b2c13c9dc462bdc697caddccd347 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Wed, 29 Jul 2020 15:55:13 +0200
Subject: Added elf loading and test app

---
 src/features/elf.c | 39 +++++++++++++++++++++++++++++++++++++++
 src/features/gui.c |  2 +-
 2 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 src/features/elf.c

(limited to 'src/features')

diff --git a/src/features/elf.c b/src/features/elf.c
new file mode 100644
index 0000000..339add0
--- /dev/null
+++ b/src/features/elf.c
@@ -0,0 +1,39 @@
+#include <assert.h>
+#include <def.h>
+#include <elf.h>
+#include <fs.h>
+#include <mem.h>
+
+int elf_verify(struct elf_header *header)
+{
+	if (header->ident[0] == ELF_MAG && header->ident[1] == 'E' && header->ident[2] == 'L' &&
+	    header->ident[3] == 'F' && header->ident[4] == ELF_32 &&
+	    header->ident[5] == ELF_LITTLE && header->ident[6] == ELF_CURRENT &&
+	    header->machine == ELF_386 && (header->type == ET_REL || header->type == ET_EXEC)) {
+		return 1;
+	}
+	return 0;
+}
+
+void elf_load(char *path)
+{
+	u32 *data = read_file(path);
+
+	struct elf_header *h = (struct elf_header *)data;
+	assert(elf_verify(h));
+
+	struct elf_program_header *p = (struct elf_program_header *)((u32)data + h->phoff);
+	struct elf_program_header *p_end =
+		(struct elf_program_header *)((u32)p + (h->phentsize * h->phnum));
+
+	u32 offset = (p->vaddr - p->paddr);
+	while (p < p_end) {
+		memcpy((void *)p->paddr, (void *)((u32)data + p->offset), p->filesz);
+		p++;
+	}
+
+	void (*entry)();
+	entry = (void (*)())(h->entry - offset);
+
+	entry();
+}
diff --git a/src/features/gui.c b/src/features/gui.c
index fa0641c..d080cb1 100644
--- a/src/features/gui.c
+++ b/src/features/gui.c
@@ -37,7 +37,7 @@ void gui_write(int x, int y, const u32 c[3], char *text)
 }
 
 // Abstraction
-int x, y = 1;
+int x, y = 0;
 const u32 c[3] = { 0xff, 0xff, 0xff };
 void gui_term_write_char(char ch)
 {
-- 
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