kern
changeset 29:8ea6debe4265
starting on the task switching implementation
| author | John Tsiombikas <nuclear@siggraph.org> |
|---|---|
| date | Sat, 23 Apr 2011 00:51:18 +0300 |
| parents | 9939a6d7a45a |
| children | a2c6110bd24b |
| files | src/intr.c src/proc.h src/segm.c src/segm.h src/tss.h |
| diffstat | 5 files changed, 59 insertions(+), 2 deletions(-) [+] |
line diff
1.1 --- a/src/intr.c Wed Apr 06 07:42:44 2011 +0300 1.2 +++ b/src/intr.c Sat Apr 23 00:51:18 2011 +0300 1.3 @@ -159,7 +159,7 @@ 1.4 desc->d[3] = (addr & 0xffff0000) >> 16; 1.5 } 1.6 1.7 -#define IS_TRAP(n) ((n) < 32) 1.8 +#define IS_TRAP(n) ((n) >= 32 && !IS_IRQ(n)) 1.9 static void set_intr_entry(int num, void (*handler)(void)) 1.10 { 1.11 int type = IS_TRAP(num) ? GATE_TRAP : GATE_INTR;
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 2.2 +++ b/src/proc.h Sat Apr 23 00:51:18 2011 +0300 2.3 @@ -0,0 +1,14 @@ 2.4 +#ifndef PROC_H_ 2.5 +#define PROC_H_ 2.6 + 2.7 +#include "tss.h" 2.8 + 2.9 +struct process { 2.10 + int id; 2.11 + 2.12 + struct task_state tss; 2.13 + 2.14 + struct process *next; 2.15 +}; 2.16 + 2.17 +#endif /* PROC_H_ */
3.1 --- a/src/segm.c Wed Apr 06 07:42:44 2011 +0300 3.2 +++ b/src/segm.c Sat Apr 23 00:51:18 2011 +0300 3.3 @@ -11,6 +11,8 @@ 3.4 #define BIT_CODE (1 << 11) 3.5 #define BIT_NOSYS (1 << 12) 3.6 #define BIT_PRESENT (1 << 15) 3.7 +/* TSS busy bit */ 3.8 +#define BIT_BUSY (1 << 9) 3.9 3.10 /* bits for the last 16bit part of the descriptor */ 3.11 #define BIT_BIG (1 << 6) 3.12 @@ -19,7 +21,11 @@ 3.13 3.14 enum {TYPE_DATA, TYPE_CODE}; 3.15 3.16 +#define TSS_TYPE_BITS 0x900 3.17 +#define TSS_BUSY BIT_BUSY 3.18 + 3.19 static void segm_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, int type); 3.20 +static void task_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, unsigned int busy); 3.21 3.22 /* these functions are implemented in segm-asm.S */ 3.23 void setup_selectors(uint16_t code, uint16_t data); 3.24 @@ -27,7 +33,7 @@ 3.25 3.26 3.27 /* our global descriptor table */ 3.28 -static desc_t gdt[3]; 3.29 +static desc_t gdt[6]; 3.30 3.31 3.32 void init_segm(void) 3.33 @@ -35,6 +41,9 @@ 3.34 memset(gdt, 0, sizeof gdt); 3.35 segm_desc(gdt + SEGM_KCODE, 0, 0xffffffff, 0, TYPE_CODE); 3.36 segm_desc(gdt + SEGM_KDATA, 0, 0xffffffff, 0, TYPE_DATA); 3.37 + segm_desc(gdt + SEGM_UCODE, 0, 0xffffffff, 3, TYPE_CODE); 3.38 + segm_desc(gdt + SEGM_UDATA, 0, 0xffffffff, 3, TYPE_DATA); 3.39 + /*task_desc(gdt + SEGM_TASK, 0, 0xffffffff, 3, TSS_BUSY);*/ 3.40 3.41 set_gdt((uint32_t)gdt, sizeof gdt - 1); 3.42 3.43 @@ -64,3 +73,13 @@ 3.44 */ 3.45 desc->d[3] = ((limit >> 16) & 0xf) | ((base >> 16) & 0xff00) | BIT_GRAN | BIT_BIG; 3.46 } 3.47 + 3.48 +static void task_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, unsigned int busy) 3.49 +{ 3.50 + desc->d[0] = limit & 0xffff; 3.51 + desc->d[1] = base & 0xffff; 3.52 + 3.53 + desc->d[2] = ((base >> 16) & 0xff) | ((dpl & 3) << 13) | BIT_PRESENT | 3.54 + TSS_TYPE_BITS | busy; 3.55 + desc->d[3] = ((limit >> 16) & 0xf) | ((base >> 16) & 0xff00) | BIT_GRAN; 3.56 +}
4.1 --- a/src/segm.h Wed Apr 06 07:42:44 2011 +0300 4.2 +++ b/src/segm.h Sat Apr 23 00:51:18 2011 +0300 4.3 @@ -3,6 +3,9 @@ 4.4 4.5 #define SEGM_KCODE 1 4.6 #define SEGM_KDATA 2 4.7 +#define SEGM_UCODE 3 4.8 +#define SEGM_UDATA 4 4.9 +#define SEGM_TASK 5 4.10 4.11 void init_segm(void); 4.12
5.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 5.2 +++ b/src/tss.h Sat Apr 23 00:51:18 2011 +0300 5.3 @@ -0,0 +1,21 @@ 5.4 +#ifndef TSS_H_ 5.5 +#define TSS_H_ 5.6 + 5.7 +#include <inttypes.h> 5.8 + 5.9 +struct task_state { 5.10 + uint32_t prev_task; 5.11 + uint32_t esp0, ss0; 5.12 + uint32_t esp1, ss1; 5.13 + uint32_t esp2, ss2; 5.14 + uint32_t cr3; 5.15 + uint32_t eip; 5.16 + uint32_t eflags; 5.17 + uint32_t eax, ecx, edx, ebx; 5.18 + uint32_t esp, ebp, esi, edi; 5.19 + uint32_t es, cs, ss, ds, fs, gs; 5.20 + uint32_t ldt_sel; 5.21 + uint16_t trap, iomap_addr; 5.22 +} __attribute__((packed)); 5.23 + 5.24 +#endif /* TSS_H_ */