Getting ready to add a TSS.

src/kernel/arch/x86/boot.s

@@ -86,6 +86,15 @@ gdt_udata:
 .byte 0b11001111         # 2nd flags | limit
 .byte 0x0                # base
 
+# TODO: setup the TSS
+gdt_tss:
+.word 0x0                # size of TSS (set later)
+.word 0x0                # address of TSS (set later)
+.byte 0x0                # address of TSS (set later)
+.byte 0b10010001         # 1st flags | type flags
+.byte 0b01000000         # 2nd flags | size of TSS (set later
+.byte 0x0                # address of TSS (set later)
+
 gdt_end:
 
 gdtr:

src/kernel/arch/x86/tss.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2018  Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+volatile struct tss {
+	uint16_t link;
+	uint16_t link_r;    // reserved
+
+	uint32_t esp0;
+	uint16_t ss0;
+	uint16_t ss0_r;     // reserved
+
+	uint32_t esp1;
+	uint16_t ss1;
+	uint16_t ss1_r;     // reserved
+
+	uint32_t esp2;
+	uint16_t ss2;
+	uint16_t ss2_r;     // reserved
+
+	uint32_t cr3;
+	uint32_t eip;
+	uint32_t eflags;
+	uint32_t eax;
+	uint32_t ecx;
+	uint32_t edx;
+	uint32_t ebx;
+	uint32_t esp;
+	uint32_t ebp;
+	uint32_t esi;
+	uint32_t edi;
+
+	uint16_t es;
+	uint16_t es_r;     // reserved
+	uint16_t cs;
+	uint16_t cs_r;     // reserved
+	uint16_t ss;
+	uint16_t ss_r;     // reserved
+	uint16_t ds;
+	uint16_t ds_r;     // reserved
+	uint16_t fs;
+	uint16_t fs_r;     // reserved
+	uint16_t gs;
+	uint16_t gs_r;     // reserved
+	uint16_t ldtr;
+	uint16_t ldtr_r;   // reserved
+	uint16_t iopb_r;   // reserved
+	uint16_t iopb;
+} __attribute__((packed));
+
+struct tss tss;