Implement ELF loading ; arrange so that user processes run.

3 files changed, 29 insertions, 14 deletions

diff --git a/src/kernel/core/gdt.c b/src/kernel/core/gdt.c
index 97e6661..ed7abe0 100644
--- a/src/kernel/core/gdt.c
+++ b/src/kernel/core/gdt.c
@@ -4,27 +4,25 @@
 #define GDT_ENTRIES 6	// The contents of each entry is defined in gdt_init.
 
 /* 	One entry of the table */
-struct gdt_entry {
+typedef struct {
 	uint16_t limit_low;
 	uint16_t base_low;
 	uint8_t base_middle;
 	uint8_t access;
 	uint8_t granularity;
 	uint8_t base_high;
-} __attribute__((packed));
-typedef struct gdt_entry gdt_entry_t;
+} __attribute__((packed)) gdt_entry_t;
 
 /*	Structure defining the whole table : address and size (in bytes). */
-struct gdt_ptr {
+typedef struct {
 	uint16_t limit;
 	uint32_t base;
-} __attribute__((packed));
-typedef struct gdt_ptr gdt_ptr_t;
+} __attribute__((packed)) gdt_ptr_t;
 
 /*	The TSS is used for hardware multitasking.
 	We don't use that, but we still need a TSS so that user mode process exceptions
 	can be handled correctly by the kernel.	*/
-struct tss_entry {
+typedef struct {
 	uint32_t prev_tss;   // The previous TSS - if we used hardware task switching this would form a linked list.
 	uint32_t esp0;       // The stack pointer to load when we change to kernel mode.
 	uint32_t ss0;        // The stack segment to load when we change to kernel mode.
@@ -52,8 +50,7 @@ struct tss_entry {
 	uint32_t ldt;        // Unused...
 	uint16_t trap;
 	uint16_t iomap_base;
-} __attribute__((packed));
-typedef struct tss_entry tss_entry_t;
+} __attribute__((packed)) tss_entry_t;
 
 // ========================= //
 // Actual definitions
@@ -86,13 +83,11 @@ void gdt_init() {
 	gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);		//User data segment		0x20
 
 	// Write TSS
-	memset(&tss_entry, 0, sizeof(tss_entry));
+	memset(&tss_entry, 0, sizeof(tss_entry_t));
 
 	tss_entry.ss0  = 0x10;
 	tss_entry.esp0 = 0;
-
-	tss_entry.cs   = 0x0b;
-	tss_entry.ss = tss_entry.ds = tss_entry.es = tss_entry.fs = tss_entry.gs = 0x13;
+	tss_entry.iomap_base = sizeof(tss_entry_t);
 
 	uint32_t tss_base = (uint32_t)&tss_entry;
 	uint32_t tss_limit = tss_base + sizeof(tss_entry_t);
diff --git a/src/kernel/core/kmain.c b/src/kernel/core/kmain.c
index 34438aa..5572ac4 100644
--- a/src/kernel/core/kmain.c
+++ b/src/kernel/core/kmain.c
@@ -15,6 +15,8 @@
 
 #include <vfs.h>
 #include <nullfs.h>
+#include <process.h>
+#include <elf.h>
 
 #include <slab_alloc.h>
 #include <hashtbl.h>
@@ -333,6 +335,23 @@ void kernel_init_stage2(void* data) {
 
 	test_cmdline(mbd, devfs);
 
+	fs_handle_t *init_bin = fs_open(devfs, "/mod/init.bin", FM_READ | FM_MMAP);
+	if (init_bin == 0) PANIC("No init.bin module provided!");
+	if (!is_elf(init_bin)) PANIC("init.bin is not valid ELF32 binary");
+
+	process_t *init_p = new_process(0);
+	ASSERT(init_p != 0);
+
+	bool add_devfs_ok = proc_add_fs(init_p, devfs, "dev");
+	ASSERT(add_devfs_ok);
+
+	proc_entry_t *e = elf_load(init_bin, init_p);
+	if (e == 0) PANIC("Could not load ELF file init.bin");
+
+	unref_file(init_bin);
+
+	start_process(init_p, e);
+
 	//TODO :
 	// - (OK) populate devfs with information regarding kernel command line & modules
 	// - create user process with init module provided on command line
diff --git a/src/kernel/core/paging.c b/src/kernel/core/paging.c
index 74331c0..5a58c8c 100644
--- a/src/kernel/core/paging.c
+++ b/src/kernel/core/paging.c
@@ -221,7 +221,8 @@ bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 		}
 
 		current_pd->page[pt] = pd->page[pt] =
-			(new_pt_frame << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW;
+			(new_pt_frame << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW
+			| ((size_t)vaddr < K_HIGHHALF_ADDR ? PTE_USER : 0);
 		invlpg(&current_pt[pt]);
 	}
 	current_pt[pt].page[page] =