diff options
Diffstat (limited to 'kernel/gdt.c')
| -rw-r--r-- | kernel/gdt.c | 71 |
1 files changed, 57 insertions, 14 deletions
diff --git a/kernel/gdt.c b/kernel/gdt.c index f72f1ab..24b52f7 100644 --- a/kernel/gdt.c +++ b/kernel/gdt.c @@ -1,4 +1,3 @@ -// http://wiki.osdev.org/GDT_Tutorial #include "kernel.h" #include "gdt.h" #include "asm_gdt.h" @@ -8,28 +7,69 @@ #define GDT_SIZE 6 -//https://wiki.osdev.org/Task_State_Segment -//Define the TSS as a global structure, boah TODO: move to own page? +static uint8_t gdt_structs[GDT_SIZE*8*SMP_MAX_PROC]; // GLOBAL DESCRIPTOR TABLES + +typedef volatile struct strtss{ + unsigned short link; + unsigned short link_h; + unsigned long esp0; + unsigned short ss0; + unsigned short ss0_h; + unsigned long esp1; + unsigned short ss1; + unsigned short ss1_h; + unsigned long esp2; + unsigned short ss2; + unsigned short ss2_h; + unsigned long cr3; + unsigned long eip; + unsigned long eflags; + unsigned long eax; + unsigned long ecx; + unsigned long edx; + unsigned long ebx; + unsigned long esp; + unsigned long ebp; + unsigned long esi; + unsigned long edi; + unsigned short es; + unsigned short es_h; + unsigned short cs; + unsigned short cs_h; + unsigned short ss; + unsigned short ss_h; + unsigned short ds; + unsigned short ds_h; + unsigned short fs; + unsigned short fs_h; + unsigned short gs; + unsigned short gs_h; + unsigned short ldt; + unsigned short ldt_h; + unsigned short trap; + unsigned short iomap; +}__attribute__((packed)) tss_struct; + tss_struct sys_tss[SMP_MAX_PROC]; +typedef struct GDT_struct +{ + uint32_t base; + uint32_t limit; + uint32_t type; +}GDT; + void install_tss(uint32_t cpu,uint32_t esp0){ // now fill each value // set values necessary sys_tss[cpu].ss0 = 0x10; //kernel data sys_tss[cpu].esp0 = esp0; - // now set the IO bitmap (not necessary, so set above limit) // sys_tss.iomap = ( unsigned short ) sizeof( tss_struct ); } -typedef struct GDT_struct -{ - uint32_t base; - uint32_t limit; - uint32_t type; -}GDT; - +/* //alternative struct gdt_entry_bits { @@ -51,6 +91,7 @@ struct gdt_entry_bits unsigned int gran :1; //1 to use 4k page addressing, 0 for byte addressing unsigned int base_high :8; } __packed; //or __attribute__((packed)) +*/ void setup_gdt(uint8_t *gdt_struct) { @@ -105,6 +146,8 @@ void gdt_init() { static int last_cpu=0; + if(last_cpu>=SMP_MAX_PROC)kpanic("not enough SMP_MAX_PROC"); + /* Pr=1 Privl 1 Exec DC RW Ac 0x9A == 1001 1010 == 1 00 1 1 0 1 0 @@ -113,8 +156,9 @@ void gdt_init() 0xF2 == 1111 0010 == 1 11 1 0 0 1 0 */ -//static uint8_t gdt_struct[GDT_SIZE*8]; // GLOBAL DESCRIPTOR TABLE - uint8_t *gdt_struct=kballoc(1); //[GDT_SIZE*8]; // GLOBAL DESCRIPTOR TABLE + //static uint8_t gdt_struct[GDT_SIZE*8]; // GLOBAL DESCRIPTOR TABLE + //uint8_t *gdt_struct=kballoc(1); //[GDT_SIZE*8]; // GLOBAL DESCRIPTOR TABLE + uint8_t *gdt_struct=&gdt_structs[GDT_SIZE*8*last_cpu]; GDT myGDT[GDT_SIZE]; //selector 0x0 @@ -156,6 +200,5 @@ void gdt_init() last_cpu++; setup_gdt(gdt_struct); - } |