diff options
Diffstat (limited to 'i386/util/gdt.c')
-rw-r--r-- | i386/util/gdt.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/i386/util/gdt.c b/i386/util/gdt.c new file mode 100644 index 0000000..7bfa6aa --- /dev/null +++ b/i386/util/gdt.c @@ -0,0 +1,80 @@ +/* + * Mach Operating System + * Copyright (c) 1991,1990 Carnegie Mellon University + * Copyright (c) 1991 IBM Corporation + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation, + * and that the name IBM not be used in advertising or publicity + * pertaining to distribution of the software without specific, written + * prior permission. + * + * CARNEGIE MELLON AND IBM ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON AND IBM DISCLAIM ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ + +#include "cpu.h" +#include "vm_param.h" + + +/* Initialize the 32-bit kernel code and data segment descriptors + to point to the base of the kernel linear space region. */ +gdt_desc_initializer(KERNEL_CS, + kvtolin(0), 0xffffffff, + ACC_PL_K|ACC_CODE_R, SZ_32); +gdt_desc_initializer(KERNEL_DS, + kvtolin(0), 0xffffffff, + ACC_PL_K|ACC_DATA_W, SZ_32); + +/* Initialize the 16-bit real-mode code and data segment descriptors. */ +gdt_desc_initializer(KERNEL_16_CS, + kvtolin(0), 0xffff, + ACC_PL_K|ACC_CODE_R, SZ_16); +gdt_desc_initializer(KERNEL_16_DS, + kvtolin(0), 0xffff, + ACC_PL_K|ACC_DATA_W, SZ_16); + +/* Initialize the linear-space data segment descriptor. */ +gdt_desc_initializer(LINEAR_CS, + 0, 0xffffffff, + ACC_PL_K|ACC_CODE_R, SZ_32); +gdt_desc_initializer(LINEAR_DS, + 0, 0xffffffff, + ACC_PL_K|ACC_DATA_W, SZ_32); + +/* Initialize the master LDT and TSS descriptors. */ +#ifdef ENABLE_KERNEL_LDT +gdt_desc_initializer(KERNEL_LDT, + kvtolin(&cpu->tables.ldt), sizeof(cpu->tables.ldt)-1, + ACC_PL_K|ACC_LDT, 0); +#endif +#ifdef ENABLE_KERNEL_TSS +gdt_desc_initializer(KERNEL_TSS, + kvtolin(&cpu->tables.tss), sizeof(cpu->tables.tss)-1, + ACC_PL_K|ACC_TSS, 0); +#endif + + +void cpu_gdt_init(struct cpu *cpu) +{ + /* Initialize all the selectors of the GDT. */ +#define gdt_sel(name) cpu_gdt_init_##name(cpu); +#include "gdt_sels.h" +#undef gdt_sel +} + |