Kernel processes / multitasking

kernel/hal/hal.h

@@ -23,6 +23,10 @@ void hal_init_withmalloc(void);
 #if defined(__x86_64__)
 # define HAL_PAGE_SIZE 0x1000
 # include "x86_64/vmm.h"
+# include "x86_64/proc.h"
+# include "x86_64/switch.h"
+# include "x86_64/paging.h"
+# include "x86_64/cpu.h"
 #endif
 
 #endif // KERNEL_HAL_HAL_H_

kernel/hal/x86_64/cpu.c

@@ -1,13 +1,13 @@
 #include <stdint.h>
 #include <stddef.h>
 
-uint64_t cpu_rdmsr(uint32_t id) {
+uint64_t hal_cpu_rdmsr(uint32_t id) {
   uint32_t lo, hi;
   asm volatile("rdmsr" : "=m"(lo), "=d"(hi) : "c"(id));
   return ((uint64_t)lo) | ((uint64_t)hi << 32);
 }
 
-uint64_t cpu_wrmsr(uint32_t id, uint64_t val) {
+uint64_t hal_cpu_wrmsr(uint32_t id, uint64_t val) {
   uint32_t lo = val & 0xffffffff, hi = (val >> 32) & 0xffffffff;
   asm volatile("wrmsr" :: "a"(lo), "d"(hi), "c"(id) : "memory");
   return val;

kernel/hal/x86_64/cpu.h

@@ -1,7 +1,11 @@
 #ifndef HAL_CPU_H_
 #define HAL_CPU_H_
 
-uint64_t cpu_rdmsr(uint32_t id);
-uint64_t cpu_wrmsr(uint32_t id, uint64_t val);
+#define HAL_CPU_FSBASE  0xC0000100
+#define HAL_CPU_GSBASE  0xC0000101
+#define HAL_CPU_KGSBASE 0xC0000102
+
+uint64_t hal_cpu_rdmsr(uint32_t id);
+uint64_t hal_cpu_wrmsr(uint32_t id, uint64_t val);
 
 #endif // HAL_CPU_H_

kernel/hal/x86_64/intr.c

@@ -10,6 +10,7 @@
 #include "pic.h"
 #include "apic.h"
 #include "pit.h"
+#include "proc/proc.h"
 
 void hal_intr_disable(void) {
   asm volatile("cli");
@@ -151,7 +152,7 @@ void intr_dumpframe(IntrStackFrame *frame) {
 void intr_handleintr(IntrStackFrame *frame) {
   if (frame->trapnum >= 0 && frame->trapnum <= 31) {
     // EXCEPTION
-    kprintf_unsafe("ERROR", "%s, 0x%lX\n", exceptions[frame->trapnum], frame->errnum);
+    kprintf_unsafe("ERROR %s, 0x%lX\n", exceptions[frame->trapnum], frame->errnum);
     intr_dumpframe(frame);
     hal_hang();  
   } else if (frame->trapnum >= 32 && frame->trapnum <= 47) {
@@ -161,6 +162,8 @@ void intr_handleintr(IntrStackFrame *frame) {
     }
     io_out8(PIC1_CMD, 0x20);
     lapic_write(LAPIC_EOI, 0x00);
+
+    proc_sched((void *)frame);
   }
 }
 

kernel/hal/x86_64/intr0.S

@@ -1,3 +1,5 @@
+#include "regs.S"
+
 .extern intr_handleintr
 
 .global intr_vec0
@@ -49,38 +51,6 @@
 .global intr_vec46
 .global intr_vec47
 
-.macro _push_regs
-  push %rax
-  push %rcx
-  push %rdx
-  push %rsi
-  push %rdi
-  push %r8
-  push %r9
-  push %r10
-  push %r11
-  push %r12
-  push %r13
-  push %r14
-  push %r15
-.endm
-
-.macro _pop_regs
-  pop %r15
-  pop %r14
-  pop %r13
-  pop %r12
-  pop %r11
-  pop %r10
-  pop %r9
-  pop %r8
-  pop %rdi
-  pop %rsi
-  pop %rdx
-  pop %rcx
-  pop %rax
-.endm
-
 .macro _vecintr_errorcode_present_save num
   pushq $\num
 .endm

kernel/hal/x86_64/paging.S

@@ -2,8 +2,3 @@
 hal_loadpd:
   mov %rdi, %cr3
   retq
-
-.global hal_invalpg
-hal_invalpg:
-  invlpg (%rdi)
-  retq

kernel/hal/x86_64/paging.h

@@ -0,0 +1,6 @@
+#ifndef HAL_PAGING_H_
+#define HAL_PAGING_H_
+
+void hal_loadpd(PgTable *cr3);
+
+#endif // HAL_PAGING_H_

kernel/hal/x86_64/proc.h

@@ -0,0 +1,15 @@
+#ifndef HAL_PROC_H_
+#define HAL_PROC_H_
+
+#include <stdint.h>
+#include "intr.h"
+#include "vmm.h"
+
+typedef struct {
+  uint64_t fsbase;
+  IntrStackFrame trapframe;
+  uint8_t *kstack;
+  PgTable *cr3;
+} ProcPlatformData;
+
+#endif // HAL_PROC_H_

kernel/hal/x86_64/regs.S

@@ -0,0 +1,31 @@
+.macro _push_regs
+  push %rax
+  push %rcx
+  push %rdx
+  push %rsi
+  push %rdi
+  push %r8
+  push %r9
+  push %r10
+  push %r11
+  push %r12
+  push %r13
+  push %r14
+  push %r15
+.endm
+
+.macro _pop_regs
+  pop %r15
+  pop %r14
+  pop %r13
+  pop %r12
+  pop %r11
+  pop %r10
+  pop %r9
+  pop %r8
+  pop %rdi
+  pop %rsi
+  pop %rdx
+  pop %rcx
+  pop %rax
+.endm

kernel/hal/x86_64/switch.S

@@ -0,0 +1,19 @@
+#include "regs.S"
+
+siema:
+  jmp siema
+
+.global hal_switchproc
+hal_switchproc:
+  mov %cr3, %rcx
+  cmp %rsi, %rcx
+  je .done
+  mov %rsi, %cr3
+.done:
+  mov %rdi, %rsp
+
+  _pop_regs
+  add $0x10, %rsp
+
+  iretq
+

kernel/hal/x86_64/switch.h

@@ -0,0 +1,6 @@
+#ifndef HAL_SWITCH_H_
+#define HAL_SWITCH_H_
+
+extern void hal_switchproc(void *newsp, PgTable *cr3);
+
+#endif // HAL_SWITCH_H_

kernel/hal/x86_64/vmm.c

@@ -4,6 +4,7 @@
 #include "hal/hal.h"
 #include "bootinfo/bootinfo.h"
 #include "pmm/pmm.h"
+#include "paging.h"
 
 PgTable *KERNEL_CR3 = NULL;
 
@@ -60,6 +61,41 @@ void hal_vmm_unmap_page(PgTable *pml4, uint64_t virtaddr, uint64_t physaddr) {
   *pte &= ~HAL_PG_PRESENT;
 }
 
+void hal_vmm_map_range(PgTable *cr3, void *virtstart, void *physstart, size_t size, uint32_t flags) {
+  if (size % HAL_PAGE_SIZE != 0 || (uint64_t)virtstart % HAL_PAGE_SIZE != 0 || (uint64_t)physstart % HAL_PG_PRESENT != 0) {
+    return;
+  }
+
+  uint8_t *vaddr = virtstart, *paddr = physstart;
+
+  for (; vaddr <= ((uint8_t *)virtstart + size); vaddr += HAL_PAGE_SIZE, paddr += HAL_PAGE_SIZE) {
+    hal_vmm_map_page(cr3, (uint64_t)vaddr, (uint64_t)paddr, flags);
+  }
+}
+
+void hal_vmm_unmap_range(PgTable *cr3, void *virtstart, void *physstart, size_t size, uint32_t flags) {
+  if (size % HAL_PAGE_SIZE != 0 || (uint64_t)virtstart % HAL_PAGE_SIZE != 0 || (uint64_t)physstart % HAL_PG_PRESENT != 0) {
+    return;
+  }
+
+  uint8_t *vaddr = virtstart, *paddr = physstart;
+
+  for (; vaddr <= ((uint8_t *)virtstart + size); vaddr += HAL_PAGE_SIZE, paddr += HAL_PAGE_SIZE) {
+    hal_vmm_unmap_page(cr3, (uint64_t)vaddr, (uint64_t)paddr);
+  }
+}
+
+void hal_vmm_map_kern(PgTable *cr3) {
+  PgTable *kcr3 = BOOT_INFO.hhdm_off + KERNEL_CR3;
+  for (size_t i = 256; i < 512; i++) {
+    cr3->ents[i] = kcr3->ents[i];
+  }
+}
+
+void hal_vmm_switch_pd(PgTable *cr3) {
+  hal_loadpd(cr3);
+}
+
 void hal_vmm_init(void) {
   KERNEL_CR3 = hal_vmm_current_cr3();
 }

kernel/hal/x86_64/vmm.h

@@ -41,5 +41,8 @@ extern PgTable *KERNEL_CR3;
 void hal_vmm_init(void);
 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);
 
 #endif // HAL_VMM_H_