Hello user process

.gitignore

@@ -1,5 +1,4 @@
 /limine
 /iso_root
-/base_root
 *.iso
 *.img

Makefile

@@ -1,7 +1,10 @@
-.PHONY: all clean prepare cleanall iso base
+.PHONY: clean prepare cleanall iso base kernel user
 
-all:
+kernel:
-	make -C kernel all
+	make -C kernel ROOT=$(PWD) all
+
+user:
+	make -C user ROOT=$(PWD) all
 
 prepare:
 	if [ ! -d limine ]; then \
@@ -13,10 +16,10 @@ prepare:
 cleanall:
 	make clean
 	rm -rf limine
-	rm -rf littlefs-fuse
 
 clean:
 	make -C kernel clean
+	make -C user clean
 	rm -f mop2.iso base.img
 
 base:

base/bin/.gitignore

@@ -0,0 +1,3 @@
+*
+!.gitignore
+!.gitkeep

kernel/Makefile

@@ -29,7 +29,7 @@ endif
 include arch/$(ARCH)/$(ARCH).mk
 include extconf/extra.mk
 
-LDFLAGS := -nostdlib -static -T arch/$(ARCH)/link.ld $(shell $(CC) -print-libgcc-file-name)
+LDFLAGS += -nostdlib -static -T arch/$(ARCH)/link.ld $(shell $(CC) -print-libgcc-file-name)
 
 SRCFILES := $(wildcard *.c) \
 	$(wildcard printf/*.c) \

kernel/elf.h

@@ -0,0 +1,355 @@
+#ifndef ELF_H_
+#define ELF_H_
+
+#include <stdint.h>
+
+#define ELFCLASS64 2
+#define ELFDATA2LSB 1
+#define ELFOSABI_SYSV 0
+#define EM_X86_64 62
+
+#define SHT_NULL 0
+#define SHT_PROGBITS 1
+#define SHT_SYMTAB 2
+#define SHT_STRTAB 3
+#define SHT_RELA 4
+#define SHT_HASH 5
+#define SHT_DYNAMIC 6
+#define SHT_NOBITS 8
+#define SHT_DYNSYM 11
+
+#define SHF_WRITE 1
+#define SHF_ALLOC 2
+#define SHF_EXECINSTR 4
+
+typedef uint64_t Elf64_Addr;
+typedef uint64_t Elf64_Off;
+typedef uint16_t Elf64_Half;
+typedef uint32_t Elf64_Word;
+typedef int32_t Elf64_Sword;
+typedef uint64_t Elf64_Xword;
+typedef int64_t Elf64_Sxword;
+
+typedef uint32_t Elf32_Addr;
+typedef uint32_t Elf32_Off;
+typedef uint16_t Elf32_Half;
+typedef uint32_t Elf32_Word;
+typedef int32_t Elf32_Sword;
+typedef uint64_t Elf32_Xword;
+typedef int64_t Elf32_Sxword;
+
+#define EI_NIDENT (16)
+
+typedef struct {
+  unsigned char e_ident[EI_NIDENT]; /* ELF identification */
+  Elf32_Half e_type;                /* Object file type */
+  Elf32_Half e_machine;             /* Machine type */
+  Elf32_Word e_version;             /* Object file version */
+  Elf32_Addr e_entry;               /* Entry point address */
+  Elf32_Off e_phoff;                /* Program header offset */
+  Elf32_Off e_shoff;                /* Section header offset */
+  Elf32_Word e_flags;               /* Processor-specific flags */
+  Elf32_Half e_ehsize;              /* ELF header size */
+  Elf32_Half e_phentsize;           /* Size of program header entry */
+  Elf32_Half e_phnum;               /* Number of program header entries */
+  Elf32_Half e_shentsize;           /* Size of section header entry */
+  Elf32_Half e_shnum;               /* Number of section header entries */
+  Elf32_Half e_shstrndx;            /* Section name string table index */
+} Elf32_Ehdr;
+
+typedef struct {
+  unsigned char e_ident[EI_NIDENT]; /* ELF identification */
+  Elf64_Half e_type;                /* Object file type */
+  Elf64_Half e_machine;             /* Machine type */
+  Elf64_Word e_version;             /* Object file version */
+  Elf64_Addr e_entry;               /* Entry point address */
+  Elf64_Off e_phoff;                /* Program header offset */
+  Elf64_Off e_shoff;                /* Section header offset */
+  Elf64_Word e_flags;               /* Processor-specific flags */
+  Elf64_Half e_ehsize;              /* ELF header size */
+  Elf64_Half e_phentsize;           /* Size of program header entry */
+  Elf64_Half e_phnum;               /* Number of program header entries */
+  Elf64_Half e_shentsize;           /* Size of section header entry */
+  Elf64_Half e_shnum;               /* Number of section header entries */
+  Elf64_Half e_shstrndx;            /* Section name string table index */
+} Elf64_Ehdr;
+
+enum {
+  ET_NONE = 0,
+  ET_REL = 1,
+  ET_EXEC = 2,
+  ET_DYN = 3,
+  ET_CORE = 4,
+};
+
+enum { SHN_UNDEF = 0, SHN_ABS = 0xFFF1 };
+
+typedef struct {
+  Elf64_Word st_name;
+  unsigned char st_info;
+  unsigned char st_other;
+  Elf64_Half st_shndx;
+  Elf64_Addr st_value;
+  Elf64_Xword st_size;
+} Elf64_Sym;
+
+enum { STB_GLOBAL = 1, STB_WEAK = 2, STB_GNU_UNIQUE = 10 };
+
+enum { STT_OBJECT = 1, STT_FUNC = 2, STT_TLS = 6 };
+
+enum {
+  R_X86_64_NONE = 0,
+  R_X86_64_64 = 1,
+  R_X86_64_COPY = 5,
+  R_X86_64_GLOB_DAT = 6,
+  R_X86_64_JUMP_SLOT = 7,
+  R_X86_64_RELATIVE = 8,
+  R_X86_64_DTPMOD64 = 16,
+  R_X86_64_DTPOFF64 = 17,
+  R_X86_64_TPOFF64 = 18,
+};
+
+enum {
+  R_AARCH64_ABS64 = 257,
+  R_AARCH64_COPY = 1024,
+  R_AARCH64_GLOB_DAT = 1025,
+  R_AARCH64_JUMP_SLOT = 1026,
+  R_AARCH64_RELATIVE = 1027,
+  R_AARCH64_TLS_TPREL = 1030,
+  R_AARCH64_TLSDESC = 1031
+};
+
+typedef struct {
+  Elf64_Addr r_offset;
+  uint64_t r_info;
+} Elf64_Rel;
+
+typedef struct {
+  Elf64_Addr r_offset;
+  Elf64_Xword r_info;
+  Elf64_Sxword r_addend;
+} Elf64_Rela;
+
+static inline Elf64_Xword ELF64_R_SYM(Elf64_Xword info) { return info >> 32; }
+static inline Elf64_Xword ELF64_R_TYPE(Elf64_Xword info) {
+  return info & 0xFFFFFFFF;
+}
+
+enum {
+  PT_LOAD = 1,
+  PT_DYNAMIC = 2,
+  PT_INTERP = 3,
+  PT_NOTE = 4,
+  PT_PHDR = 6,
+  PT_TLS = 7,
+  PT_GNU_EH_FRAME = 0x6474E550,
+  PT_GNU_STACK = 0x6474E551,
+  PT_GNU_RELRO = 0x6474E552,
+  PT_GNU_PROPERTY = 0x6474E553,
+};
+
+enum { PF_X = 1, PF_W = 2, PF_R = 4 };
+
+typedef struct {
+  Elf64_Word p_type;    /* Type of segment */
+  Elf64_Word p_flags;   /* Segment attributes */
+  Elf64_Off p_offset;   /* Offset in file */
+  Elf64_Addr p_vaddr;   /* Virtual address in memory */
+  Elf64_Addr p_paddr;   /* Reserved */
+  Elf64_Xword p_filesz; /* Size of segment in file */
+  Elf64_Xword p_memsz;  /* Size of segment in memory */
+  Elf64_Xword p_align;  /* Alignment of segment */
+} Elf64_Phdr;
+
+enum {
+  DT_NULL = 0,
+  DT_NEEDED = 1,
+  DT_PLTRELSZ = 2,
+  DT_PLTGOT = 3,
+  DT_HASH = 4,
+  DT_STRTAB = 5,
+  DT_SYMTAB = 6,
+  DT_RELA = 7,
+  DT_RELASZ = 8,
+  DT_RELAENT = 9,
+  DT_STRSZ = 10,
+  DT_SYMENT = 11,
+  DT_INIT = 12,
+  DT_FINI = 13,
+  DT_SONAME = 14,
+  DT_RPATH = 15,
+  DT_SYMBOLIC = 16,
+  DT_REL = 17,
+  DT_BIND_NOW = 24,
+  DT_INIT_ARRAY = 25,
+  DT_FINI_ARRAY = 26,
+  DT_INIT_ARRAYSZ = 27,
+  DT_FINI_ARRAYSZ = 28,
+  DT_RUNPATH = 29,
+  DT_PLTREL = 20,
+  DT_DEBUG = 21,
+  DT_JMPREL = 23,
+  DT_FLAGS = 30,
+  DT_GNU_HASH = 0x6ffffef5,
+  DT_TLSDESC_PLT = 0x6ffffef6,
+  DT_TLSDESC_GOT = 0x6ffffef7,
+  DT_VERSYM = 0x6ffffff0,
+  DT_RELACOUNT = 0x6ffffff9,
+  DT_FLAGS_1 = 0x6ffffffb,
+  DT_VERDEF = 0x6ffffffc,
+  DT_VERDEFNUM = 0x6ffffffd,
+  DT_VERNEED = 0x6ffffffe,
+  DT_VERNEEDNUM = 0x6fffffff
+};
+
+enum {
+  // For DT_FLAGS.
+  DF_SYMBOLIC = 0x02,
+  DF_STATIC_TLS = 0x10,
+
+  // For DT_FLAGS_1.
+  DF_1_NOW = 0x00000001
+};
+
+typedef struct {
+  Elf32_Sword d_tag;
+  union {
+    Elf32_Word d_val;
+    Elf32_Addr d_ptr;
+  } d_un;
+} Elf32_Dyn;
+
+typedef struct {
+  Elf64_Sxword d_tag;
+  union {
+    Elf64_Xword d_val;
+    Elf64_Addr d_ptr;
+  } d_un;
+} Elf64_Dyn;
+
+typedef struct {
+  Elf32_Word sh_name;
+  Elf32_Word sh_type;
+  Elf32_Word sh_flags;
+  Elf32_Addr sh_addr;
+  Elf32_Off sh_offset;
+  Elf32_Word sh_size;
+  Elf32_Word sh_link;
+  Elf32_Word sh_info;
+  Elf32_Word sh_addralign;
+  Elf32_Word sh_entsize;
+} Elf32_Shdr;
+
+typedef struct {
+  Elf64_Word sh_name;
+  Elf64_Word sh_type;
+  Elf64_Xword sh_flags;
+  Elf64_Addr sh_addr;
+  Elf64_Off sh_offset;
+  Elf64_Xword sh_size;
+  Elf64_Word sh_link;
+  Elf64_Word sh_info;
+  Elf64_Xword sh_addralign;
+  Elf64_Xword sh_entsize;
+} Elf64_Shdr;
+
+typedef struct {
+  Elf32_Word n_namesz;
+  Elf32_Word n_descsz;
+  Elf32_Word n_type;
+} Elf32_Nhdr;
+
+typedef struct {
+  Elf64_Word n_namesz;
+  Elf64_Word n_descsz;
+  Elf64_Word n_type;
+} Elf64_Nhdr;
+
+/* ST_TYPE (subfield of st_info) values (symbol type) */
+#define STT_NOTYPE 0
+#define STT_OBJECT 1
+#define STT_FUNC 2
+#define STT_SECTION 3
+#define STT_FILE 4
+
+/* ST_BIND (subfield of st_info) values (symbol binding) */
+#define STB_LOCAL 0
+#define STB_GLOBAL 1
+#define STB_WEAK 2
+
+/* sh_type (section type) values */
+#define SHT_NULL 0
+#define SHT_PROGBITS 1
+#define SHT_SYMTAB 2
+#define SHT_STRTAB 3
+#define SHT_RELA 4
+#define SHT_NOBITS 8
+#define SHT_REL 9
+#define SHT_INIT_ARRAY 14
+#define SHT_FINI_ARRAY 15
+#define SHT_SYMTAB_SHNDX 18
+
+/* special section indices */
+#define SHN_UNDEF 0
+#define SHN_LORESERVE 0xff00
+#define SHN_COMMON 0xfff2
+#define SHN_XINDEX 0xffff
+#define SHN_HIRESERVE 0xff00
+
+/* values for e_machine */
+#define EM_NONE 0
+#define EM_SPARC 2
+#define EM_386 3
+#define EM_PPC 20
+#define EM_PPC64 21
+#define EM_X86_64 62
+
+/* e_indent constants */
+#define EI_MAG0 0
+#define ELFMAG0 0x7f
+
+#define EI_MAG1 1
+#define ELFMAG1 'E'
+
+#define EI_MAG2 2
+#define ELFMAG2 'L'
+
+#define EI_MAG3 3
+#define ELFMAG3 'F'
+
+#define EI_CLASS 4
+#define ELFCLASSNONE 0
+#define ELFCLASS32 1
+#define ELFCLASS64 2
+#define ELFCLASSNUM 3
+
+#define EI_DATA 5
+#define ELFDATANONE 0
+#define ELFDATA2LSB 1
+#define ELFDATA2MSB 2
+#define ELFDATANUM 3
+
+#define AT_NULL 0
+#define AT_IGNORE 1
+#define AT_EXECFD 2
+#define AT_PHDR 3
+#define AT_PHENT 4
+#define AT_PHNUM 5
+#define AT_PAGESZ 6
+#define AT_BASE 7
+#define AT_FLAGS 8
+#define AT_ENTRY 9
+#define AT_NOTELF 10
+#define AT_UID 11
+#define AT_EUID 12
+#define AT_GID 13
+#define AT_EGID 14
+
+typedef struct {
+  uint64_t entry;
+  uint64_t phdr;
+  uint64_t phent;
+  uint64_t phnum;
+} ElfAuxval;
+
+#endif // ELF_H_

kernel/errors.h

@@ -8,6 +8,6 @@
 #define E_OUTOFBOUNDS     -4
 #define E_UNKNOWN_SDTYPE  -5
 #define E_TODO            -6
-#define E_GENERIC_ERROR   -7
+#define E_BADIO           -7
 
 #endif // ERRORS_H_

kernel/fs/kvfs/kvfs.c

@@ -27,6 +27,22 @@ int32_t kvfs_read(struct VfsMountPoint *vmp, const char *key, uint8_t *const buf
   return E_OK;
 }
 
+int32_t kvfs_stat(struct VfsMountPoint *vmp, const char *key, struct VfsStat *stat) {
+  KvfsNode *node = NULL;
+
+  spinlock_acquire(&vmp->spinlock);
+  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
+  spinlock_release(&vmp->spinlock);
+
+  if (node == NULL) {
+    return E_NOENTRY;
+  }
+
+  stat->type = VFS_TYPE_FILE;
+  stat->size = KVFS_BUFFER_SIZE;
+  return E_OK;
+}
+
 int32_t kvfs_write(struct VfsMountPoint *vmp, const char *key, const uint8_t *const buffer, size_t n, size_t off) {
   KvfsNode *node = NULL;
 
@@ -85,7 +101,7 @@ int32_t kvfs_create(struct VfsMountPoint *vmp, const char *path, int32_t type) {
 bool kvfs_check(void) {
   int32_t ret;
 
-  ret = vfs_create("tmpvars", "hello", VFS_CREATE_FILE);
+  ret = vfs_create("tmpvars", "hello", VFS_TYPE_FILE);
   if (ret != E_OK) return false;
 
   char *hello = "WAWAWAWA!!!";

kernel/fs/kvfs/kvfs.h

@@ -5,6 +5,7 @@
 #include <stdbool.h>
 
 struct VfsMountPoint;
+struct VfsStat;
 
 #define KVFS_NODE_KEY_MAX 128
 #define KVFS_NODES_MAX 256
@@ -21,6 +22,7 @@ typedef struct {
 } Kvfs;
 
 int32_t kvfs_read(struct VfsMountPoint *vmp, const char *key, uint8_t *const buffer, size_t n, size_t off);
+int32_t kvfs_stat(struct VfsMountPoint *vmp, const char *key, struct VfsStat *stat);
 int32_t kvfs_write(struct VfsMountPoint *vmp, const char *key, const uint8_t *const buffer, size_t n, size_t off);
 int32_t kvfs_remove(struct VfsMountPoint *vmp, const char *key);
 int32_t kvfs_create(struct VfsMountPoint *vmp, const char *path, int32_t type);

kernel/fs/portlfs/portlfs.c

@@ -9,7 +9,6 @@
 #define CHECK(err) \
   do { \
     int ok = (err); \
-    kprintf("ok = %d\n", ok); \
     if (ok < 0) goto bad; \
   } while(0)
 
@@ -27,7 +26,29 @@ int32_t littlefs_read(struct VfsMountPoint *vmp, const char *path, uint8_t *cons
   return E_OK;
 bad:
   spinlock_release(&vmp->spinlock);
-  return E_GENERIC_ERROR;
+  return E_BADIO;
+}
+
+int32_t littlefs_stat(struct VfsMountPoint *vmp, const char *path, struct VfsStat *stat) {
+  spinlock_acquire(&vmp->spinlock);
+
+  LittleFs *fs = &vmp->fs.littlefs;
+  struct lfs_info stat1;
+  CHECK(lfs_stat(&fs->instance, path, &stat1));
+
+  if (stat1.type == LFS_TYPE_REG) {
+    stat->type = VFS_TYPE_FILE;
+  } else if (stat1.type == LFS_TYPE_DIR) {
+    stat->type = VFS_TYPE_DIR;
+  }
+
+  stat->size = stat1.size;
+
+  spinlock_release(&vmp->spinlock);
+  return E_OK;
+bad:
+  spinlock_release(&vmp->spinlock);
+  return E_BADIO;
 }
 
 int32_t littlefs_write(struct VfsMountPoint *vmp, const char *path, const uint8_t *const buffer, size_t n, size_t off) {
@@ -44,7 +65,7 @@ int32_t littlefs_write(struct VfsMountPoint *vmp, const char *path, const uint8_
   return E_OK;
 bad:
   spinlock_release(&vmp->spinlock);
-  return E_GENERIC_ERROR;
+  return E_BADIO;
 }
 
 int32_t littlefs_remove(struct VfsMountPoint *vmp, const char *path) {
@@ -57,7 +78,7 @@ int32_t littlefs_remove(struct VfsMountPoint *vmp, const char *path) {
   return E_OK;
 bad:
   spinlock_release(&vmp->spinlock);
-  return E_GENERIC_ERROR;
+  return E_BADIO;
 }
 
 int32_t littlefs_cleanup(struct VfsMountPoint *vmp) {
@@ -67,7 +88,7 @@ int32_t littlefs_cleanup(struct VfsMountPoint *vmp) {
     return err;
   }
   err = lfs_unmount(&vmp->fs.littlefs.instance);
-  if (err < 0) { return E_GENERIC_ERROR; }
+  if (err < 0) { return E_BADIO; }
   return E_OK;
 }
 
@@ -76,10 +97,10 @@ int32_t littlefs_create(struct VfsMountPoint *vmp, const char *path, int32_t typ
   
   LittleFs *fs = &vmp->fs.littlefs;
   switch (type) {
-    case VFS_CREATE_DIR:
+    case VFS_TYPE_DIR:
       CHECK(lfs_mkdir(&fs->instance, path));
       break;
-    case VFS_CREATE_FILE: {
+    case VFS_TYPE_FILE: {
       lfs_file_t file;
       CHECK(lfs_file_open(&fs->instance, &file, path, LFS_O_CREAT | LFS_O_WRONLY));
       CHECK(lfs_file_close(&fs->instance, &file));
@@ -90,7 +111,7 @@ int32_t littlefs_create(struct VfsMountPoint *vmp, const char *path, int32_t typ
   return E_OK;
 bad:
   spinlock_release(&vmp->spinlock);
-  return E_GENERIC_ERROR;
+  return E_BADIO;
 }
 
 bool littlefs_check(void) {

kernel/fs/portlfs/portlfs.h

@@ -8,12 +8,14 @@
 #define LITTLEFS_BLOCK_SIZE 4096
 
 struct VfsMountPoint;
+struct VfsStat;
 
 typedef struct {
   lfs_t instance;
 } LittleFs;
 
 int32_t littlefs_read(struct VfsMountPoint *vmp, const char *path, uint8_t *const buffer, size_t n, size_t off);
+int32_t littlefs_stat(struct VfsMountPoint *vmp, const char *path, struct VfsStat *stat);
 int32_t littlefs_write(struct VfsMountPoint *vmp, const char *path, const uint8_t *const buffer, size_t n, size_t off);
 int32_t littlefs_remove(struct VfsMountPoint *vmp, const char *path);
 int32_t littlefs_create(struct VfsMountPoint *vmp, const char *path, int32_t type);

kernel/hal/x86_64/vmm.c

@@ -5,6 +5,8 @@
 #include "bootinfo/bootinfo.h"
 #include "pmm/pmm.h"
 #include "paging.h"
+#include "proc/proc.h"
+#include "kprintf.h"
 
 PgTable *KERNEL_CR3 = NULL;
 
@@ -73,7 +75,7 @@ void hal_vmm_map_range(PgTable *cr3, void *virtstart, void *physstart, size_t si
   }
 }
 
-void hal_vmm_unmap_range(PgTable *cr3, void *virtstart, void *physstart, size_t size, uint32_t flags) {
+void hal_vmm_unmap_range(PgTable *cr3, void *virtstart, void *physstart, size_t size) {
   if (size % HAL_PAGE_SIZE != 0 || (uint64_t)virtstart % HAL_PAGE_SIZE != 0 || (uint64_t)physstart % HAL_PG_PRESENT != 0) {
     return;
   }
@@ -96,6 +98,21 @@ void hal_vmm_switch_pd(PgTable *cr3) {
   hal_loadpd(cr3);
 }
 
+PgTable *hal_vmm_userproc_pml4(Proc *proc) {
+  uint8_t *cr3 = pmm_alloc(1);
+  PgTable *pml4 = (PgTable *)VIRT(cr3);
+  hal_memset(pml4, 0, HAL_PAGE_SIZE);
+  
+  PgTable *kcr3 = VIRT(KERNEL_CR3);
+
+  for (size_t i = 256; i < 512; i++) {
+    pml4->ents[i] = kcr3->ents[i];
+  }
+
+  return (PgTable *)cr3;
+}
+
 void hal_vmm_init(void) {
   KERNEL_CR3 = hal_vmm_current_cr3();
+  kprintf("KERNEL_CR3 = %p\n", KERNEL_CR3);
 }

kernel/hal/x86_64/vmm.h

@@ -5,6 +5,8 @@
 #include <stdbool.h>
 #include "compiler/attr.h"
 
+struct Proc;
+
 enum {
   HAL_PG_PRESENT = 1<<0,
   HAL_PG_RW      = 1<<1,
@@ -43,6 +45,7 @@ void hal_vmm_unmap_page(PgTable *pml4, uint64_t virtaddr, uint64_t physaddr);
 void hal_vmm_map_page(PgTable *pml4, uint64_t virtaddr, uint64_t physaddr, uint32_t flags);
 PgTable *hal_vmm_current_cr3(void);
 void hal_vmm_map_range(PgTable *cr3, void *virtstart, void *physstart, size_t size, uint32_t flags);
-void hal_vmm_unmap_range(PgTable *cr3, void *virtstart, void *physstart, size_t size, uint32_t flags);
+void hal_vmm_unmap_range(PgTable *cr3, void *virtstart, void *physstart, size_t size);
+PgTable *hal_vmm_userproc_pml4(struct Proc *proc);
 
 #endif // HAL_VMM_H_

kernel/proc/proc.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include "hal/hal.h"
 #include "vmm/vmm.h"
 #include "spinlock/spinlock.h"
@@ -8,6 +9,10 @@
 #include "pmm/pmm.h"
 #include "util/util.h"
 #include "kprintf.h"
+#include "elf.h"
+#include "errors.h"
+#include "vfs/vfs.h"
+#include "bootinfo/bootinfo.h"
 
 #define PROC_REAPER_FREQ 30
 
@@ -22,7 +27,66 @@ uint64_t sched_ticks = 0;
 
 Procs PROCS;
 
+bool proc_checkelf(uint8_t *elf) {
+  if (elf[0] != 0x7f || elf[1] != 'E' || elf[2] != 'L' || elf[3] != 'F') {
+    return false;
+  }
+  return true;
+}
+
+ElfAuxval proc_load_elf_segs(Proc *proc, uint8_t *data) {
+  #if defined(__x86_64__)
+    PgTable *vas = proc->platformdata.cr3;
+  #endif
+    ElfAuxval aux = {0};
+
+  Elf64_Ehdr *elfhdr = (Elf64_Ehdr *)data;
+  aux.entry = elfhdr->e_entry;
+  aux.phnum = elfhdr->e_phnum;
+  aux.phent = elfhdr->e_phentsize;
+
+  for (uint64_t seg = 0; seg < elfhdr->e_phnum; seg++) {
+    Elf64_Phdr *phdr = (Elf64_Phdr *)(data + elfhdr->e_phoff + (elfhdr->e_phentsize * seg));
+
+    switch (phdr->p_type) {
+      case PT_PHDR: {
+        aux.phdr = (uint64_t)phdr->p_vaddr;
+      } break;
+      case PT_LOAD: {
+        uint64_t off = phdr->p_vaddr & (HAL_PAGE_SIZE - 1);
+        uint64_t blocks = (phdr->p_memsz / HAL_PAGE_SIZE) + 1;
+
+        uint8_t *physaddr = pmm_alloc(blocks);
+        uint8_t *virtaddr = (uint8_t *)(phdr->p_vaddr - off);
+
+        hal_memset(VIRT(physaddr), 0, phdr->p_memsz);
+        hal_memcpy(VIRT(physaddr) + off, (data + phdr->p_offset), phdr->p_filesz);
+
+        #if defined(__x86_64__)
+          uint32_t pgflags = HAL_PG_USER | HAL_PG_RW | HAL_PG_PRESENT;
+          hal_vmm_map_range(VIRT(vas), virtaddr, physaddr, blocks * HAL_PAGE_SIZE, pgflags);
+        #endif
+
+        VasRange *range = dlmalloc(sizeof(*range));
+        range->virtstart = virtaddr;
+        range->physstart = physaddr;
+        range->size = blocks * HAL_PAGE_SIZE;
+        #if defined(__x86_64__)
+          range->pgflags = pgflags;
+        #endif
+
+        LL_APPEND(proc->vas, range);
+      } break;
+    }
+  }
+  return aux;
+}
+
 Proc *proc_spawnkern(void (*ent)(void), char *name) {
+  if (pids >= PROC_MAX) {
+    return NULL;
+  }
+
   Proc *proc = dlmalloc(sizeof(*proc));
   if (proc == NULL) {
     return NULL;
@@ -51,6 +115,56 @@ Proc *proc_spawnkern(void (*ent)(void), char *name) {
   return proc;
 }
 
+Proc *proc_spawnuser(char *mountpoint, char *path) {
+  VfsStat stat;
+  if (vfs_stat(mountpoint, path, &stat) != E_OK) {
+    return NULL;
+  }
+  if (stat.type != VFS_TYPE_FILE) {
+    return NULL;
+  }
+
+  uint8_t *data = dlmalloc(stat.size);
+  if (vfs_read(mountpoint, path, data, stat.size, 0) != E_OK) {
+    return NULL;
+  }
+
+  Proc *proc = dlmalloc(sizeof(*proc));
+  hal_memset(proc, 0, sizeof(*proc));
+  ksprintf(proc->name, "%s:%s", mountpoint, path);
+
+  uint8_t *sp = (uint8_t *)pmm_alloc(PROC_STACKBLOCKS) + PROC_STACKSIZE;
+  uint8_t *spbase = sp - PROC_STACKSIZE;
+
+  #if defined(__x86_64__)
+    proc->platformdata.kstack = sp;
+    hal_memset(&proc->platformdata.trapframe, 0, sizeof(proc->platformdata.trapframe));
+    
+    proc->platformdata.cr3 = hal_vmm_userproc_pml4(proc);
+    uint32_t flags = HAL_PG_RW | HAL_PG_USER | HAL_PG_PRESENT;
+    hal_vmm_map_range(VIRT(proc->platformdata.cr3), spbase, spbase, PROC_STACKSIZE, flags);
+    VasRange *range = dlmalloc(sizeof(*range));
+    range->virtstart = spbase;
+    range->physstart = spbase;
+    range->size = PROC_STACKSIZE;
+    range->pgflags = flags;
+
+    LL_APPEND(proc->vas, range);
+  
+    ElfAuxval aux = proc_load_elf_segs(proc, data);
+
+    proc->platformdata.trapframe.ss = 0x20 | 0x3;
+    proc->platformdata.trapframe.rsp = (uint64_t)VIRT(sp);
+    proc->platformdata.trapframe.rflags = 0x202;
+    proc->platformdata.trapframe.cs = 0x18 | 0x3;
+    proc->platformdata.trapframe.rip = aux.entry;
+  #endif
+  proc->state = PROC_READY;
+  proc->pid = pids++;
+
+  return proc;
+}
+
 void proc_register(Proc *proc) {
   spinlock_acquire(&PROCS.spinlock);
   LL_APPEND(PROCS.procs, proc);
@@ -63,24 +177,53 @@ Proc *proc_nextready(void) {
   return proc;
 }
 
+void proc_reaper(void) {
+  Proc *head = PROCS.procs;
+  while (head) {
+    if (head->state == PROC_ZOMBIE) {
+      Proc *zombie = head;
+      head = head->next;
+
+      LL_REMOVE(PROCS.procs, zombie);
+
+      #if defined(__x86_64__)
+        pmm_free((uintptr_t)(zombie->platformdata.kstack - PROC_STACKSIZE), PROC_STACKBLOCKS);
+      #endif
+      
+      if (!zombie->kern) {
+        VasRange *vashead = zombie->vas;
+        size_t i = 0;
+        while (vashead) {
+          VasRange *tmp = vashead;
+          vashead = vashead->next;
+          #if defined(__x86_64__)
+            hal_vmm_unmap_range(zombie->platformdata.cr3, tmp->virtstart, tmp->physstart, tmp->size);
+          #endif
+          // first pmm mapping is for the elf itself
+          if (i == 0) {
+            pmm_free((uintptr_t)tmp->physstart, tmp->size / HAL_PAGE_SIZE);
+          }
+          dlfree(tmp);
+          i++;
+        }
+
+        #if defined(__x86_64__)
+          pmm_free((uintptr_t)zombie->platformdata.cr3, 1);
+        #endif
+      }
+      dlfree(zombie);
+    } else {
+      head = head->next;
+    }
+  }
+}
+
 void proc_sched(void *cpustate) {
   hal_intr_disable();
   sched_ticks++;
 
   if (sched_ticks % PROC_REAPER_FREQ == 0) {
-    Proc *head = PROCS.procs;
+    proc_reaper();
-    while (head) {
-      if (head->state == PROC_ZOMBIE) {
-        Proc *zombie = head;
-        head = head->next;
-
-        LL_REMOVE(PROCS.procs, zombie);
-        pmm_free((uintptr_t)(zombie->platformdata.kstack - PROC_STACKSIZE), PROC_STACKBLOCKS);
-        dlfree(zombie);
-      } else {
-        head = head->next;
-      }
-    }
   }
 
   #if defined(__x86_64__)
@@ -116,31 +259,18 @@ void proc_idle(void) {
   }
 }
 
-int a = 0;
+void proc_status(void) {
-
-void proc_print(void) {
   for (;;) {
-    hal_wait(1 * 1000);
+    spinlock_acquire(&PROCS.spinlock);
-    
+    Proc *head = PROCS.procs;
-    /* if (a == 10) { */
+    while (head) {
-    /*   PROC_DIE(); */
+      kprintf("%s %s\n", head->kern ? "kern" : "user", head->name);
-    /* } */
+      head = head->next;
-    kprintf("A");
+    }
-    a++;
+    kprintf("\n\n");
-  }
+    spinlock_release(&PROCS.spinlock);
-}
+  
-
+    hal_wait(3 * 1000);
-int b = 0;
-
-void proc_print2(void) {
-  for (;;) {
-    hal_wait(2 * 1000);
-    
-    /* if (b == 20) { */
-    /*   PROC_DIE(); */
-    /* } */
-    kprintf("B");
-    b++;
   }
 }
 
@@ -152,8 +282,8 @@ void proc_init(void) {
   proc_register(idle);
   PROCS.current = idle;
 
-  proc_register(proc_spawnkern(&proc_print, "print"));
+  proc_register(proc_spawnkern(&proc_status, "status"));
-  proc_register(proc_spawnkern(&proc_print2, "print"));
+  proc_register(proc_spawnuser("base", "/bin/hello"));
 
   #if defined(__x86_64__)
     hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);

kernel/proc/proc.h

@@ -12,6 +12,8 @@
 #define PROC_STACKBLOCKS 32
 #define PROC_STACKSIZE (PROC_STACKBLOCKS * BITMAP_BLOCK_SIZE)
 
+#define PROC_MAX 0x100 // max amount of processes
+
 enum {
   PROC_READY,
   PROC_RUNNING,
@@ -38,7 +40,9 @@ typedef struct {
 extern Procs PROCS;
 
 void proc_init(void);
+void proc_register(Proc *proc);
 Proc *proc_spawnkern(void (*ent)(void), char *name);
+Proc *proc_spawnuser(char *mountpoint, char *path);
 void proc_sched(void *cpustate);
 
 #endif // PROC_PROC_H_

kernel/vfs/vfs.c

@@ -18,6 +18,7 @@ VfsTable VFS_TABLE;
 
 void vfs_init_kvfs(VfsMountPoint *mp) {
   mp->read = &kvfs_read;
+  mp->stat = &kvfs_stat;
   mp->write = &kvfs_write;
   mp->remove = &kvfs_remove;
   mp->check = &kvfs_check;
@@ -52,6 +53,7 @@ void vfs_init_littlefs(VfsMountPoint *mp) {
   }
 
   mp->read = &littlefs_read;
+  mp->stat = &littlefs_stat;
   mp->write = &littlefs_write;
   mp->remove = &littlefs_remove;
   mp->check = &littlefs_check;
@@ -123,6 +125,20 @@ int32_t vfs_read(char *mountpoint, const char *path, uint8_t *const buffer, size
   return mp->read(mp, path, buffer, n, off);
 }
 
+int32_t vfs_stat(char *mountpoint, const char *path, VfsStat *stat) {
+  VfsMountPoint *mp = NULL;
+
+  spinlock_acquire(&VFS_TABLE.spinlock);
+  HSHTB_GET(&VFS_TABLE, mountpoints, mountpoint, label, mp);
+  spinlock_release(&VFS_TABLE.spinlock);
+
+  if (mp == NULL) {
+    return E_NOENTRY;
+  }
+
+  return mp->stat(mp, path, stat);
+}
+
 int32_t vfs_create(char *mountpoint, const char *path, int32_t type) {
   VfsMountPoint *mp = NULL;
 

kernel/vfs/vfs.h

@@ -23,10 +23,15 @@ static const char *vfs_strings[] = {
 };
 
 enum {
-  VFS_CREATE_DIR,
+  VFS_TYPE_DIR,
-  VFS_CREATE_FILE,
+  VFS_TYPE_FILE,
 };
 
+typedef struct VfsStat {
+  size_t size;
+  int32_t type;
+} VfsStat;
+
 typedef struct VfsMountPoint {
   bool taken;
   uint8_t label[VFS_MOUNTPOINT_LABEL_MAX];
@@ -34,6 +39,7 @@ typedef struct VfsMountPoint {
   StoreDev *backingsd;
 
   int32_t (*read)(struct VfsMountPoint *vmp, const char *path, uint8_t *const buffer, size_t n, size_t off);
+  int32_t (*stat)(struct VfsMountPoint *vmp, const char *path, struct VfsStat *stat);
   int32_t (*write)(struct VfsMountPoint *vmp, const char *path, const uint8_t *const buffer, size_t n, size_t off);
   int32_t (*remove)(struct VfsMountPoint *vmp, const char *path);
   int32_t (*create)(struct VfsMountPoint *vmp, const char *path, int32_t type);
@@ -56,9 +62,11 @@ extern VfsTable VFS_TABLE;
 
 void vfs_init(void);
 int32_t vfs_read(char *mountpoint, const char *path, uint8_t *const buffer, size_t n, size_t off);
+int32_t vfs_stat(char *mountpoint, const char *path, VfsStat *stat);
 int32_t vfs_write(char *mountpoint, const char *path, const uint8_t *const buffer, size_t n, size_t off);
 int32_t vfs_remove(char *mountpoint, const char *path);
 int32_t vfs_create(char *mountpoint, const char *path, int32_t type);
 int32_t vfs_unmount(char *mountpoint);
 
+
 #endif // VFS_VFS_H_

kernel/vmm/vmm.c

@@ -35,10 +35,10 @@ void vmm_map_kern_range(void *virtstart, void *physstart, size_t size, uint32_t
   spinlock_release(&VIRT_MEM.spinlock);
 }
 
-void vmm_unmap_kern_range(void *virtstart, void *physstart, size_t size, uint32_t flags) {
+void vmm_unmap_kern_range(void *virtstart, void *physstart, size_t size) {
   spinlock_acquire(&VIRT_MEM.spinlock);
   #if defined(__x86_64__)
-    hal_vmm_unmap_range(KERNEL_CR3, virtstart, physstart, size, flags);
+    hal_vmm_unmap_range(KERNEL_CR3, virtstart, physstart, size);
   #endif
   spinlock_release(&VIRT_MEM.spinlock);
 }

scripts/devel.sh

@@ -1,3 +1,3 @@
 #!/bin/sh
 
-make -B && make base && make iso
+make -B kernel && make -B user && make base && make iso

scripts/mkbaseimg.sh

@@ -1,6 +1,5 @@
 #!/bin/sh
 
 rm -f base.img
-rm -rf base_root
+cat user/FILES.txt | while read line; do cp -v $line base/bin; done
-mkdir -p base_root
+mklittlefs -c base -b 4096 -s $((1<<20)) base.img
-mklittlefs -c base_root -b 4096 -s $((1<<20)) base.img

user/.gitignore

@@ -0,0 +1 @@
+FILES.txt

user/Makefile

@@ -0,0 +1,14 @@
+CURRENT_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+.PHONY: all clean
+
+APP_DIR := $(shell find . -mindepth 1 -maxdepth 1 -type d -not -path "./arch")
+
+all:
+	rm -f FILES.txt
+	touch FILES.txt
+	for dir in $(APP_DIR); do make -C $$dir FILES=$(CURRENT_DIR)/FILES.txt all; done
+
+clean:
+	for dir in $(APP_DIR); do make -C $$dir clean; done
+

user/Makefile.inc

@@ -0,0 +1,9 @@
+ARCH ?= x86_64
+
+CFLAGS := -ffreestanding -Wall -Wextra -g -fcommon -nostdinc
+
+CURRENT_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+include $(CURRENT_DIR)/arch/$(ARCH)/$(ARCH).mk
+
+LDFLAGS += -nostdlib -static $(shell $(CC) -print-libgcc-file-name) -T $(CURRENT_DIR)/arch/$(ARCH)/link.ld

user/arch/x86_64/link.ld

@@ -0,0 +1,26 @@
+ENTRY(_start)
+
+SECTIONS {
+  /* . = 0xffff000000000000; */
+  . = 0x0000000000000000;
+
+  .rodata ALIGN(4K):
+  {
+    *(.rodata .rodata.*)
+  }
+
+  .text ALIGN(4K):
+  {
+    *(.text .text.*)
+  }
+
+  .data ALIGN(4K):
+  {
+    *(.data .data.*)
+  }
+
+  .bss ALIGN(4K):
+  {
+    *(.bss .bss.*)
+  }
+}

user/arch/x86_64/x86_64.mk

@@ -0,0 +1,22 @@
+CC := x86_64-elf-gcc
+LD := x86_64-elf-ld
+
+CFLAGS += -m64 \
+					-fPIE \
+					-mno-80387 \
+					-mno-mmx \
+					-mno-sse \
+					-nostartfiles \
+					-nostdlib \
+					-mno-sse2 \
+					-mno-red-zone \
+					-fno-stack-protector \
+					-fno-stack-check \
+					-Os \
+
+LDFLAGS += -m elf_x86_64 \
+					-pie \
+					--no-dynamic-linker \
+					-z text \
+					-z max-page-size=0x1000
+

user/hello/.gitignore

@@ -0,0 +1,2 @@
+*.o
+hello

user/hello/Makefile

@@ -0,0 +1,21 @@
+include ../Makefile.inc
+
+.PHONY: all clean
+
+TARGET := hello
+
+SRCFILES := $(wildcard *.s)
+ASFILES := $(filter %.s,$(SRCFILES))
+OBJ := $(patsubst %.s,%.o,$(ASFILES))
+
+%.o: %.s
+	$(CC) $(CFLAGS) -c $< -o $@
+
+all: $(TARGET)
+
+hello: $(OBJ)
+	$(LD) $^ $(LDFLAGS) -o $@
+	echo "$(realpath $@)" >> $(FILES)
+
+clean:
+	rm -f $(OBJ) $(TARGET)

user/hello/hello.s

@@ -0,0 +1,6 @@
+
+.global _start
+_start:
+.spin:
+  jmp .spin
+