Big code refactor, get rid of HAL entirely

kernel/cpu/gdt.c

@@ -0,0 +1,92 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "compiler/attr.h"
+#include "cpu/gdt.h"
+#include "std/string.h"
+
+#define GDT_PRESENT 0x80
+#define GDT_TSS     0x89
+
+#define KSTACK (1024*2*4096)
+ALIGNED(16) static uint8_t kernelstack[KSTACK];
+
+typedef struct {
+  uint16_t limitlow;
+  uint16_t baselow;
+  uint8_t basemid;
+  uint8_t access;
+  uint8_t gran;
+  uint8_t basehigh;
+} PACKED GdtEntry;
+
+typedef struct {
+  uint16_t limit;
+  uint64_t base;
+} PACKED GdtPtr;
+
+typedef struct {
+  GdtEntry old[5];
+  GdtEntry tsslow;
+  GdtEntry tsshigh;
+} PACKED ExtendedGdt;
+
+ALIGNED(16) Tss tss = {0};
+ALIGNED(16) static ExtendedGdt gdt = {0};
+
+void gdt_setentry(GdtEntry *ent, uint32_t base, uint32_t limit, uint8_t acc, uint8_t gran) {
+  ent->baselow = base & 0xffff;
+  ent->basemid = (base >> 16) & 0xff;
+  ent->basehigh = (base >> 24) & 0xff;
+  ent->limitlow = limit & 0xffff;
+  ent->gran = ((limit >> 16) & 0x0f) | (gran & 0xf0);
+  ent->access = acc;
+}
+
+void gdt_init(void) {
+  memset(&tss, 0, sizeof(tss));
+  tss.iopb_off = sizeof(tss);
+
+  tss.rsp0 = (uint64_t)(kernelstack + sizeof(kernelstack));
+
+  uint64_t tss_base = (uint64_t)&tss;
+  uint32_t tss_limit = sizeof(tss) - 1;
+
+  gdt_setentry(&gdt.old[0], 0, 0, 0, 0);
+  gdt_setentry(&gdt.old[1], 0, 0xFFFFF, 0x9a, 0xA0);
+  gdt_setentry(&gdt.old[2], 0, 0xFFFFF, 0x92, 0xC0);
+  gdt_setentry(&gdt.old[3], 0, 0xFFFFF, 0xfa, 0xA0);
+  gdt_setentry(&gdt.old[4], 0, 0xFFFFF, 0xf2, 0xC0);
+
+  gdt_setentry(&gdt.tsslow, tss_base & 0xFFFFFFFF, tss_limit, GDT_PRESENT | GDT_TSS, 0x0);
+
+  uint32_t tssbasehi = tss_base >> 32;
+  gdt.tsshigh.limitlow = tssbasehi & 0xffff;
+  gdt.tsshigh.baselow = (tssbasehi >> 16) & 0xffff;
+  gdt.tsshigh.basemid = 0;
+  gdt.tsshigh.basehigh = 0;
+  gdt.tsshigh.access = 0;
+  gdt.tsshigh.gran = 0;
+
+  GdtPtr gdtr;
+  gdtr.limit = sizeof(gdt) - 1;
+  gdtr.base = (uint64_t)&gdt;
+  asm volatile("lgdt %0" :: "m"(gdtr));
+
+  asm volatile(
+    "pushq %[kcode]\n"
+    "lea 1f(%%rip), %%rax\n"
+    "pushq %%rax\n"
+    "lretq\n"
+    "1:\n"
+    "movw %[kdata], %%ax\n"
+    "movw %%ax, %%ds\n"
+    "movw %%ax, %%es\n"
+    "movw %%ax, %%ss\n"
+    :
+    : [kcode] "i"(KCODE), [kdata] "i"(KDATA)
+    : "rax", "memory"
+  );
+
+  asm volatile("ltr %0" :: "r"((uint16_t)TSS));
+}
+

kernel/cpu/gdt.h

@@ -0,0 +1,29 @@
+#ifndef CPU_GDT_H_
+#define CPU_GDT_H_
+
+#include <stdint.h>
+#include "compiler/attr.h"
+
+#define KCODE 0x08
+#define KDATA 0x10
+#define UCODE 0x18
+#define UDATA 0x20
+#define TSS   0x28
+
+typedef struct {
+  uint32_t resv0;
+  uint64_t rsp0;
+  uint64_t rsp1;
+  uint64_t rsp2;
+  uint64_t resv1;
+  uint64_t ist[7];
+  uint64_t resv2;
+  uint16_t resv3;
+  uint16_t iopb_off;
+} PACKED Tss;
+
+ALIGNED(16) extern Tss tss;
+
+void gdt_init(void);
+
+#endif // CPU_GDT_H_

kernel/cpu/hang.c

@@ -0,0 +1,10 @@
+#include "cpu/hang.h"
+#include "intr/intr.h"
+
+void cpu_hang(void) {
+  intr_disable();
+  for(;;) {
+    asm("hlt");
+  }
+}
+

kernel/cpu/hang.h

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

kernel/cpu/regs.S

@@ -0,0 +1,33 @@
+.macro _push_regs
+  push %rax
+  push %rcx
+  push %rdx
+  push %rsi
+  push %rdi
+  push %rbp
+  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 %rbp
+  pop %rdi
+  pop %rsi
+  pop %rdx
+  pop %rcx
+  pop %rax
+.endm