C userspace programs

Makefile

@@ -1,10 +1,15 @@
 .PHONY: clean prepare cleanall iso base kernel user test
 
+ARCH ?= x86_64
+
 kernel:
-	make -C kernel ROOT=$(PWD) all
+	make -C kernel ARCH=$(ARCH) ROOT=$(PWD) all
 
 user:
-	make -C user ROOT=$(PWD) all
+	make -C user ARCH=$(ARCH) ROOT=$(PWD) all
+
+ulib:
+	make -C ulib ARCH=$(ARCH) ROOT=$(PWD) all
 
 prepare:
 	if [ ! -d limine ]; then \
@@ -18,8 +23,9 @@ cleanall:
 	rm -rf limine
 
 clean:
-	make -C kernel ROOT=$(PWD) clean
-	make -C user ROOT=$(PWD) clean
+	make -C kernel ARCH=$(ARCH) ROOT=$(PWD) clean
+	make -C user ARCH=$(ARCH) ROOT=$(PWD) clean
+	make -C ulib ARCH=$(ARCH) ROOT=$(PWD) clean
 	rm -f mop2.iso base.img
 
 base:

kernel/Makefile

@@ -2,14 +2,14 @@ include $(ROOT)/mk/grabsrc.mk
 
 .PHONY: all clean
 
-ARCH ?= x86_64
 PUTCHAR_ ?= fb
 
 CFLAGS := -ffreestanding -Wall -Wextra -g -fcommon -nostdinc
 
 CFLAGS += -I. \
           -I$(ROOT)/limine \
-          -I./std/include \
+          -I$(ROOT)/std/include \
+          -I./std \
           -I./flanterm/src \
           -DPRINTF_INCLUDE_CONFIG_H=1 \
           -DLFS_NO_ASSERT \

kernel/arch/x86_64/x86_64.mk

@@ -1,5 +1,4 @@
-CC := x86_64-elf-gcc
-LD := x86_64-elf-ld
+include $(ROOT)/mk/arch/toolchain-x86_64.mk
 
 CFLAGS += -m64 \
 					-fPIE \

kernel/hal/x86_64/cpu.c

@@ -6,8 +6,6 @@
 #include "hal/hal.h"
 #include "bootinfo/bootinfo.h"
 
-LocalCpuData HAL_CPUS[HAL_CPUS_MAX];
-
 uint64_t hal_cpu_rdmsr(uint32_t id) {
   uint32_t lo, hi;
   asm volatile("rdmsr" : "=a"(lo), "=d"(hi) : "c"(id));
@@ -21,8 +19,3 @@ uint64_t hal_cpu_wrmsr(uint32_t id, uint64_t val) {
   return val;
 }
 
-void hal_cpu_init(uint32_t cpu) {
-  void *addr = pmm_alloc(16) + (16 * HAL_PAGE_SIZE);
-  HAL_CPUS[cpu].syscall_kstack = (uint64_t *)VIRT(addr);
-  HAL_CPUS[cpu].kcr3 = hal_vmm_current_cr3();
-}

kernel/hal/x86_64/cpu.h

@@ -13,24 +13,13 @@
 #define HAL_CPU_STAR    0xC0000081
 #define HAL_CPU_LSTAR   0xC0000082
 #define HAL_CPU_CSTAR   0xC0000083
-#define HAL_CPU_SFMASK  0xC0000084
+#define HAL_CPU_FMASK   0xC0000084
 
 #define HAL_CPU_FSBASE  0xC0000100
 #define HAL_CPU_GSBASE  0xC0000101
 #define HAL_CPU_KGSBASE 0xC0000102
 
-typedef struct {
-  uint64_t *syscall_kstack;
-  uint64_t *syscall_ustack;
-  PgTable *kcr3;
-  PgTable *pcr3;
-  IntrStackFrame *frame;
-} PACKED LocalCpuData;
-
 uint64_t hal_cpu_rdmsr(uint32_t id);
 uint64_t hal_cpu_wrmsr(uint32_t id, uint64_t val);
-void hal_cpu_init(uint32_t cpu);
-
-extern LocalCpuData HAL_CPUS[HAL_CPUS_MAX];
 
 #endif // HAL_CPU_H_

kernel/hal/x86_64/hal.c

@@ -9,7 +9,6 @@
 #include "pic.h"
 #include "apic.h"
 #include "pit.h"
-#include "syscall.h"
 
 void hal_init(void) {
   if (!serial_init()) {
@@ -33,7 +32,6 @@ void hal_init_withmalloc(void) {
   pit_init();
   ioapic_setentry(IOAPIC, acpi_remapirq(0x00), INTR_TIMER);
   hal_intr_disable();
-  hal_syscall_init();
 }
 
 void hal_wait(uint32_t ms) {

kernel/hal/x86_64/intr.c

@@ -11,6 +11,8 @@
 #include "apic.h"
 #include "pit.h"
 #include "proc/proc.h"
+#include "syscall/syscall.h"
+#include "errors.h"
 
 void hal_intr_disable(void) {
   asm volatile("cli");
@@ -122,6 +124,9 @@ void intr_init(void) {
   MKINTR(45, 0);
   MKINTR(46, 0);
   MKINTR(47, 0);
+    
+  extern void intr_vec128(void);
+  idt_setentry(0x80, (uint64_t)&intr_vec128, 0, 0xEE);
 
   idt_init();
 }
@@ -149,14 +154,33 @@ void intr_dumpframe(IntrStackFrame *frame) {
     );
 }
 
+void hal_syscalldispatch(IntrStackFrame *frame) {
+  uint64_t sysnum = frame->regs.rax;
+  if (sysnum < SYSCALLS_MAX) {
+    SyscallFn fn = SYSCALL_TABLE[sysnum];
+    if (fn == NULL) {
+      frame->regs.rax = E_BADSYSCALL;
+      return;
+    }
+    int32_t ret = fn(frame->regs.rdi, frame->regs.rsi, frame->regs.rdx,
+                     frame->regs.r10, frame->regs.r8,  frame->regs.r9);
+
+    if (sysnum == SYS_QUITPROC) {
+      proc_sched((void *)frame);
+    }
+    frame->regs.rax = *(uint64_t *)&ret;
+  }
+}
+
 void intr_handleintr(IntrStackFrame *frame) {
   if (frame->trapnum <= 31) {
+    kprintf("ERROR %s, 0x%lX\n", exceptions[frame->trapnum], frame->errnum);
+    intr_dumpframe(frame);
     if (frame->trapnum == 14 && frame->errnum & 0x4) {
+      kprintf("killed pid %ld %s\n", PROCS.current->pid, PROCS.current->name);
       proc_killself();
       proc_sched((void *)frame);
     }
-    kprintf("ERROR %s, 0x%lX\n", exceptions[frame->trapnum], frame->errnum);
-    intr_dumpframe(frame);
     hal_hang();
   } else if (frame->trapnum >= 32 && frame->trapnum <= 47) {
     if (frame->trapnum == INTR_TIMER) {
@@ -167,6 +191,8 @@ void intr_handleintr(IntrStackFrame *frame) {
     lapic_write(LAPIC_EOI, 0x00);
 
     proc_sched((void *)frame);
+  } else if (frame->trapnum == 0x80) {
+    hal_syscalldispatch(frame);
   }
 }
 

kernel/hal/x86_64/intr0.S

@@ -50,6 +50,7 @@
 .global intr_vec45
 .global intr_vec46
 .global intr_vec47
+.global intr_vec128
 
 .macro _vecintr_errorcode_present_save num
   pushq $\num
@@ -215,3 +216,6 @@ intr_vec46:
 intr_vec47: 
   _vecintr_plain_save 47
   _vecintr_bodygen
+intr_vec128: 
+  _vecintr_plain_save 128
+  _vecintr_bodygen

kernel/hal/x86_64/syscall.c

@@ -1,43 +0,0 @@
-#include <stdint.h>
-#include "syscall.h"
-#include "cpu.h"
-#include "intr.h"
-#include "syscall/syscall.h"
-#include "proc/proc.h"
-#include "kprintf.h"
-#include "errors.h"
-
-extern void hal_enable_syscallentry(void);
-extern void hal_syscallentry(void);
-
-void hal_syscalldispatch(IntrStackFrame *frame) {
-  uint64_t sysnum = frame->regs.rax;
-  if (sysnum < SYSCALLS_MAX) {
-    SyscallFn fn = SYSCALL_TABLE[sysnum];
-    if (fn == NULL) {
-      frame->regs.rax = E_BADSYSCALL;
-      return;
-    }
-    int32_t ret = fn(frame->regs.rdi, frame->regs.rsi, frame->regs.rdx,
-                     frame->regs.r10, frame->regs.r8,  frame->regs.r9);
-
-    if (sysnum == SYS_QUITPROC) {
-      proc_sched((void *)frame);
-    }
-    frame->regs.rax = *(uint64_t *)&ret;
-  }
-}
-
-void hal_syscall_init(void) {
-  hal_cpu_init(0);
-  LocalCpuData *lcd = &HAL_CPUS[0];
-
-  hal_cpu_wrmsr(HAL_CPU_EFER, hal_cpu_rdmsr(HAL_CPU_EFER) | 0x1);
-  hal_enable_syscallentry();
-
-  hal_cpu_wrmsr(HAL_CPU_GSBASE, (uint64_t)lcd);
-  hal_cpu_wrmsr(HAL_CPU_KGSBASE, (uint64_t)lcd);
-  hal_cpu_wrmsr(HAL_CPU_SFMASK, (uint64_t)0);
-
-  hal_cpu_wrmsr(HAL_CPU_LSTAR, (uint64_t)&hal_syscallentry);
-}

kernel/hal/x86_64/syscall.h

@@ -1,6 +0,0 @@
-#ifndef HAL_SYSCALL_H_
-#define HAL_SYSCALL_H_
-
-void hal_syscall_init(void);
-
-#endif // HAL_SYSCALL_H_

kernel/hal/x86_64/syscall0.S

@@ -1,48 +0,0 @@
-#include "regs.S"
-
-.extern hal_syscalldispatch
-
-.global hal_enable_syscallentry
-hal_enable_syscallentry:
-  movq $0xC0000080, %rcx
-  rdmsr
-  or $0x1, %eax
-  wrmsr
-  movq $0xC0000081, %rcx
-  rdmsr
-  movl $0x180008, %edx
-  wrmsr
-  ret
-
-.global hal_syscallentry
-hal_syscallentry:
-  cli
-  swapgs
-
-  movq %rsp, %gs:0x8
-  movq %gs:0x0, %rsp
-
-  pushq $0x23
-  pushq %gs:0x8
-
-  swapgs
-
-  pushq %r11
-  pushq $0x1b
-  pushq %rcx
-
-  _push_regs
-
-  mov %rsp, %rdi
-  mov $0x0, %rbp
-
-  call hal_syscalldispatch
-  cli
-
-  _pop_regs
-
-  popq %rcx
-  add $0x8, %rsp
-  popq %r11
-  popq %rsp
-  sysret

kernel/proc/proc.c

@@ -155,7 +155,7 @@ Proc *proc_spawnuser(char *mountpoint, char *path) {
   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.rsp = (uint64_t)sp;
   proc->platformdata.trapframe.rflags = 0x202;
   proc->platformdata.trapframe.cs = 0x18 | 0x3;
   proc->platformdata.trapframe.rip = aux.entry;
@@ -231,13 +231,10 @@ void proc_sched(void *cpustate) {
   IntrStackFrame *frame = cpustate;
 
   PROCS.current->platformdata.trapframe = *frame;
-  PROCS.current->platformdata.fsbase = hal_cpu_rdmsr(HAL_CPU_FSBASE);
     
   PROCS.current = proc_nextready();
   PROCS.current->state = PROC_RUNNING;
 
-  hal_cpu_wrmsr(HAL_CPU_FSBASE, PROCS.current->platformdata.fsbase);
-  HAL_CPUS[0].syscall_kstack = VIRT(PROCS.current->platformdata.kstack);
   hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
 }
 
@@ -282,8 +279,8 @@ void proc_init(void) {
   proc_register(idle);
   PROCS.current = idle;
 
-  proc_register(proc_spawnkern(&proc_status, "status"));
-  proc_register(proc_spawnuser("base", "/bin/hello"));
+  /* proc_register(proc_spawnkern(&proc_status, "status")); */
+  proc_register(proc_spawnuser("base", "/bin/init"));
 
   hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
 }

kernel/proc/proc.h

@@ -14,7 +14,6 @@
 #define PROC_MAX 0x100 // max amount of processes
 
 typedef struct {
-  uint64_t fsbase;
   IntrStackFrame trapframe;
   uint8_t *kstack;
   PgTable *cr3;

kernel/syscall/syscall.c

@@ -5,14 +5,9 @@
 #include "kprintf.h"
 #include "proc/proc.h"
 
-int32_t SYSCALL2(sys_debugprint, string1, len) {
-  char *buf = dlmalloc(len);
-  if (buf == NULL) {
-    return E_NOMEMORY;
-  }
-  ksnprintf(buf, len, "%s", string1);
-  kprintf("%s\n", buf);
-  dlfree(buf);
+int32_t SYSCALL1(sys_debugprint, string) {
+  char *p = (char *)string;
+  kprintf("%s\n", p);
   return E_OK;
 }
 

mk/arch/toolchain-x86_64.mk

@@ -0,0 +1,3 @@
+CC := x86_64-elf-gcc
+LD := x86_64-elf-ld
+AR := x86_64-elf-ar

mk/user/x86_64.mk

@@ -0,0 +1,13 @@
+CFLAGS += -m64 \
+					-fPIE \
+					-mno-80387 \
+					-mno-mmx \
+					-mno-sse \
+					-nostartfiles \
+					-nostdlib \
+					-mno-sse2 \
+					-mno-red-zone \
+					-fno-stack-protector \
+					-fno-stack-check \
+					-fno-builtin \
+					-Os \

scripts/devel.sh

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

std/include/stdatomic.h

@@ -20,6 +20,6 @@
 #define atomic_compare_exchange_strong(p, old, new) \
   __atomic_compare_exchange_n(p, old, new, false, memory_order_relaxed, memory_order_relaxed)
 
-#define atomic_bool volatile bool
+#define atomic_bool _Atomic(bool)
 
 #endif

ulib/.gitignore

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

ulib/Makefile

@@ -0,0 +1,33 @@
+include $(ROOT)/mk/grabsrc.mk
+include $(ROOT)/mk/arch/toolchain-$(ARCH).mk
+include $(ROOT)/mk/user/$(ARCH).mk
+
+.PHONY: all clean
+
+SRCFILES := $(call GRABSRC, \
+							. \
+							syscall \
+							string \
+							system \
+						)
+
+CFLAGS += -isystem $(ROOT)/ulib -isystem $(ROOT)/std/include
+
+ASFILES := $(call GET_ASFILES, $(SRCFILES))
+CFILES := $(call GET_CFILES, $(SRCFILES))
+OBJ := $(call GET_OBJ, $(SRCFILES))
+
+%.o: %.S
+	$(CC) $(CFLAGS) -c $< -o $@
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+libulib.a: $(OBJ)
+	$(AR) rcs libulib.a $(OBJ)
+
+all: libulib.a
+
+clean:
+	rm -f $(OBJ)
+	rm -f libulib.a

ulib/_premain.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <stddef.h>
+
+extern void main(void);
+
+extern uint8_t _bss_start[];
+extern uint8_t _bss_end[];
+
+void bss_clear(void) {
+  uint8_t *p = _bss_start;
+  while (p != _bss_end) {
+    *p = 0;
+    p++;
+  }
+}
+
+// ulib initialization goes here
+void _premain(void) {
+  bss_clear();
+  main();
+}
+

ulib/_start.S

@@ -0,0 +1,10 @@
+#include <syscall/syscall.h>
+
+.extern _premain
+
+.global _start
+_start:
+  call _premain
+
+  mov $SYS_QUITPROC, %rax
+  int $0x80

ulib/string/string.c

@@ -0,0 +1,11 @@
+#include <stddef.h>
+#include <string/string.h>
+
+size_t string_len(const char *s) {
+  size_t l = 0;
+  while (*s != '\0') {
+    l++;
+    s++;
+  }
+  return l;
+}

ulib/string/string.h

@@ -0,0 +1,8 @@
+#ifndef ULIB_STRING_STRING_H_
+#define ULIB_STRING_STRING_H_
+
+#include <stddef.h>
+
+size_t string_len(const char *s);
+
+#endif // ULIB_STRING_STRING_H_

ulib/syscall/syscall.c

@@ -0,0 +1,27 @@
+#include <stdint.h>
+
+uint64_t syscall(uint64_t num, uint64_t arg1, uint64_t arg2,
+    uint64_t arg3, uint64_t arg4, uint64_t arg5, uint64_t arg6) {
+  uint64_t ret = 0;
+  asm volatile (
+    "mov %[SYSNUM], %%rax\n"
+    "mov %[ARG1], %%rdi\n"
+    "mov %[ARG2], %%rsi\n"
+    "mov %[ARG3], %%rdx\n"
+    "mov %[ARG4], %%r10\n"
+    "mov %[ARG5], %%r8\n"
+    "mov %[ARG6], %%r9\n"
+    "int $0x80\n"
+    "mov %%rax, %[RESULT]\n"
+    : [RESULT]"=r"(ret)
+    : [SYSNUM]"r"(num),
+      [ARG1]"r"(arg1),
+      [ARG2]"r"(arg2),
+      [ARG3]"r"(arg3),
+      [ARG4]"r"(arg4),
+      [ARG5]"r"(arg5),
+      [ARG6]"r"(arg6)
+    : "%rax", "%rdi", "%rsi", "%rdx", "%r10", "%r8", "%r9", "memory"
+  );
+  return ret;
+}

ulib/syscall/syscall.h

@@ -0,0 +1,14 @@
+#ifndef ULIB_SYSCALL_SYSCALL_H_
+#define ULIB_SYSCALL_SYSCALL_H_
+
+#define SYS_DEBUGPRINT  1
+#define SYS_QUITPROC    2
+
+#if !defined(__ASSEMBLER__)
+
+uint64_t syscall(uint64_t num, uint64_t arg1, uint64_t arg2,
+    uint64_t arg3, uint64_t arg4, uint64_t arg5, uint64_t arg6);
+
+#endif // ! __ASSEMBLER__
+
+#endif // ULIB_SYSCALL_SYSCALL_H_

ulib/system/system.c

@@ -0,0 +1,9 @@
+#include <stdint.h>
+#include <system/system.h>
+#include <syscall/syscall.h>
+
+
+void sys_debugprint(const char *string) {
+  syscall(SYS_DEBUGPRINT, (uint64_t)string, 0, 0, 0, 0, 0);
+}
+

ulib/system/system.h

@@ -0,0 +1,6 @@
+#ifndef ULIB_SYSTEM_SYSTEM_H_
+#define ULIB_SYSTEM_SYSTEM_H_
+
+void sys_debugprint(const char *string);
+
+#endif // ULIB_SYSTEM_SYSTEM_H_

user/Makefile.inc

@@ -1,6 +1,5 @@
-ARCH ?= x86_64
-
-CFLAGS := -ffreestanding -Wall -Wextra -g -fcommon -nostdinc
+CFLAGS := -ffreestanding -Wall -Wextra -g -fcommon -nostdinc \
+          -isystem $(ROOT)/std/include -isystem $(ROOT)/ulib
 
 CURRENT_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 

user/arch/x86_64/link.ld

@@ -1,17 +1,17 @@
 ENTRY(_start)
 
 SECTIONS {
-  . = 0x0000000000000000;
-
-  .rodata ALIGN(4K):
-  {
-    *(.rodata .rodata.*)
-  }
+  /* . = 0x0000000000000000; */
 
   .text ALIGN(4K):
   {
     *(.text .text.*)
   }
+  
+  .rodata (READONLY): ALIGN(4K)
+  {
+    *(.rodata .rodata.*)
+  }
 
   .data ALIGN(4K):
   {
@@ -20,6 +20,8 @@ SECTIONS {
 
   .bss ALIGN(4K):
   {
+    _bss_start = .;
     *(.bss .bss.*)
+    _bss_end = .;
   }
 }

user/arch/x86_64/x86_64.mk

@@ -1,18 +1,5 @@
-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 \
+include $(ROOT)/mk/user/x86_64.mk
+include $(ROOT)/mk/arch/toolchain-x86_64.mk
 
 LDFLAGS += -m elf_x86_64 \
 					-pie \

user/hello/Makefile

@@ -14,9 +14,9 @@ OBJ := $(call GET_OBJ, $(SRCFILES))
 
 all: $(TARGET)
 
-hello: $(OBJ)
+$(TARGET): $(OBJ)
 	$(LD) $^ $(LDFLAGS) -o $@
-	echo $(realpath hello) >> $(FILES)
+	echo $$(realpath $(TARGET)) >> $(FILES)
 
 clean:
 	rm -f $(OBJ) $(TARGET)

user/hello/hello.s

@@ -11,8 +11,7 @@ _start:
   movq $1, %rax
   lea STRING(%rip), %rdi
   lea STRING_LEN(%rip), %rsi
-  syscall
+  int $0x80
 
   movq $2, %rax
-  syscall
-
+  int $0x80

user/init/.gitignore

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

user/init/Makefile

@@ -0,0 +1,24 @@
+include $(ROOT)/mk/grabsrc.mk
+include ../Makefile.inc
+
+.PHONY: all clean
+
+TARGET := init
+
+LDFLAGS += -L$(ROOT)/ulib -l:libulib.a
+
+SRCFILES := $(call GRABSRC, .)
+CFILES := $(call GET_CFILES, $(SRCFILES))
+OBJ := $(call GET_OBJ, $(SRCFILES))
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+all: $(TARGET)
+
+$(TARGET): $(OBJ)
+	$(LD) $^ $(LDFLAGS) -o $@
+	echo $$(realpath $(TARGET)) >> $(FILES)
+
+clean:
+	rm -f $(OBJ) $(TARGET)

user/init/main.c

@@ -0,0 +1,6 @@
+#include <system/system.h>
+
+void main(void) {
+  sys_debugprint("Hello world from userspace in C");
+}
+