Well basically nothing really works I guess

I've worked quite a while on several small things which I didn't commit but I'm going away for a week (holiday) soooo I synced these useless and dumb files :)

4 files changed, 177 insertions, 0 deletions

diff --git a/src/kernel/fs/elf.h b/src/kernel/fs/elf.h
new file mode 100644
index 0000000..9be6b4d
--- /dev/null
+++ b/src/kernel/fs/elf.h
@@ -0,0 +1,53 @@
+#ifndef MELVIX_ELF_H
+#define MELVIX_ELF_H
+
+#include <stdint.h>
+
+typedef struct {
+    uint32_t sig;
+} elf_priv_data;
+
+typedef struct {
+    unsigned char e_ident[16];
+    uint16_t e_type;
+    uint16_t e_machine;
+    uint32_t e_version;
+    uint32_t e_entry;
+    uint32_t e_phoff;
+    uint32_t e_shoff;
+    uint32_t e_flags;
+    uint16_t e_ehsize;
+    uint16_t e_phentsize;
+    uint16_t e_phnum;
+    uint16_t e_shentsize;
+    uint16_t e_shnum;
+    uint16_t e_shstrndx;
+} elf_header_t;
+
+typedef struct {
+    uint32_t sh_name;
+    uint32_t sh_type;
+    uint32_t sh_flags;
+    uint32_t sh_addr;
+    uint32_t sh_offset;
+    uint32_t sh_size;
+    uint32_t sh_link;
+    uint32_t sh_info;
+    uint32_t sh_addralign;
+    uint32_t sh_entsize;
+} elf_section_header_t;
+
+typedef struct {
+    uint32_t p_type;
+    uint32_t p_offset;
+    uint32_t p_vaddr;
+    uint32_t p_paddr;
+    uint32_t p_filesz;
+    uint32_t p_memsz;
+    uint32_t p_flags;
+    uint32_t p_align;
+} elf_program_header_t;
+
+void elf_init();
+
+#endif
diff --git a/src/kernel/fs/elfloader.c b/src/kernel/fs/elfloader.c
new file mode 100644
index 0000000..5b81a5e
--- /dev/null
+++ b/src/kernel/fs/elfloader.c
@@ -0,0 +1,64 @@
+#include <kernel/fs/elf.h>
+#include <kernel/lib/stdio.h>
+#include <kernel/memory/alloc.h>
+#include <kernel/lib/lib.h>
+#include <kernel/memory/paging.h>
+#include "load.h"
+
+elf_priv_data *elf_probe(uint8_t *buf)
+{
+    elf_header_t *header = (elf_header_t *) buf;
+    /* The first four bytes are 0x7f and 'ELF' */
+    if (header->e_ident[0] == 0x7f &&
+        header->e_ident[1] == 'E' && header->e_ident[2] == 'L' && header->e_ident[3] == 'F') {
+        /* Valid ELF! */
+        serial_printf("Buffer is valid ELF file!");
+        return (void *) 1;
+    }
+    return 0;
+}
+
+uint8_t elf_start(uint8_t *buf)
+{
+    elf_header_t *header = (elf_header_t *) buf;
+    serial_printf("Type: %s%s%s",
+                  header->e_ident[4] == 1 ? "32bit " : "64 bit",
+                  header->e_ident[5] == 1 ? "Little Endian " : "Big endian ",
+                  header->e_ident[6] == 1 ? "True ELF " : "buggy ELF ");
+    if (header->e_type != 2) {
+        serial_printf("File is not executable!");
+        return 0;
+    }
+    /* Map the virtual space */
+    uint32_t phys_loc = loader_get_unused_load_location();
+    uint32_t cr3 = kmalloc(4096);
+    /* Find first program header and loop through them */
+    elf_program_header_t *ph = (elf_program_header_t *) (buf + header->e_phoff);
+    for (int i = 0; i < header->e_phnum; i++, ph++) {
+        switch (ph->p_type) {
+            case 0: /* NULL */
+                break;
+            case 1: /* LOAD */
+                serial_printf("LOAD: offset 0x%x vaddr 0x%x paddr 0x%x filesz 0x%x memsz 0x%x",
+                              ph->p_offset, ph->p_vaddr, ph->p_paddr, ph->p_filesz, ph->p_memsz);
+                paging_map(phys_loc, ph->p_vaddr, PT_PRESENT | PT_RW | PT_USED);
+                memcpy(ph->p_vaddr, buf + ph->p_offset, ph->p_filesz);
+                break;
+            default: /* @TODO add more */
+                serial_printf("Unsupported p_type! Bail out!");
+                return 0;
+        }
+    }
+
+    return 0;//START("elf32", header->e_entry);
+}
+
+void elf_init()
+{
+    loader_t *elfloader = (loader_t *) kmalloc(sizeof(loader_t));
+    elfloader->name = "ELF32";
+    elfloader->probe = (void *) elf_probe;
+    elfloader->start = (void *) elf_start;
+    register_loader(elfloader);
+    // _kill();
+}
\ No newline at end of file
diff --git a/src/kernel/fs/load.c b/src/kernel/fs/load.c
index cd422d0..5a476b5 100644
--- a/src/kernel/fs/load.c
+++ b/src/kernel/fs/load.c
@@ -5,6 +5,8 @@
 #include <kernel/system.h>
 #include <kernel/fs/iso9660/iso9660.h>
 #include <kernel/memory/alloc.h>
+#include <kernel/lib/stdio.h>
+#include <kernel/lib/lib.h>
 
 void load_binaries()
 {
@@ -31,4 +33,46 @@ void load_binaries()
         kfree(user_e);
     }
     vga_log("Successfully loaded binaries");
+}
+
+#define MAX_LOADERS 16
+
+loader_t **loaders = 0;
+uint8_t last_loader = 0;
+
+uint32_t last_load_loc = 0x400000;
+
+void loader_init()
+{
+    serial_printf("Setting up loader");
+    loaders = (loader_t **) kmalloc(MAX_LOADERS * sizeof(uint32_t));
+    memset(loaders, 0, MAX_LOADERS * sizeof(uint32_t));
+    // _kill();
+}
+
+void register_loader(loader_t *load)
+{
+    if (last_loader + 1 > MAX_LOADERS) return;
+    if (!load) return;
+    loaders[last_loader] = load;
+    last_loader++;
+    serial_printf("Registered %s loader as id %d", load->name, last_loader - 1);
+}
+
+uint32_t loader_get_unused_load_location()
+{
+    last_load_loc += 0x400000;
+    return last_load_loc;
+}
+
+uint8_t exec_start(uint8_t *buf)
+{
+    for (int i = 0; i < MAX_LOADERS; i++) {
+        if (!loaders[i]) break;
+        void *priv = loaders[i]->probe(buf);
+        if (priv) {
+            return loaders[i]->start(buf, priv);
+        }
+    }
+    return 0;
 }
\ No newline at end of file
diff --git a/src/kernel/fs/load.h b/src/kernel/fs/load.h
index 7a0ec06..4ba545f 100644
--- a/src/kernel/fs/load.h
+++ b/src/kernel/fs/load.h
@@ -16,4 +16,20 @@ struct font {
 
 void load_binaries();
 
+typedef struct {
+    char *name;
+
+    void *(*probe)(uint8_t *buf);
+
+    uint8_t (*start)(uint8_t *buf, void *priv);
+} loader_t;
+
+void loader_init();
+
+void register_loader(loader_t *load);
+
+uint8_t exec_start(uint8_t *buf);
+
+uint32_t loader_get_unused_load_location();
+
 #endif