kern
annotate src/segm-asm.S @ 90:7ff2b4971216
started work on the filesystem
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Fri, 09 Dec 2011 13:44:15 +0200 |
| parents | 4eaecb14fe31 |
| children |
| rev | line source |
|---|---|
| nuclear@7 | 1 .data |
| nuclear@8 | 2 .align 4 |
| nuclear@8 | 3 /* memory reserved for setup_selectors */ |
| nuclear@7 | 4 off:.long 0 |
| nuclear@7 | 5 seg:.short 0 |
| nuclear@8 | 6 /* memory reserved for set_gdt */ |
| nuclear@8 | 7 lim:.short 0 |
| nuclear@8 | 8 addr:.long 0 |
| nuclear@7 | 9 |
| nuclear@7 | 10 .text |
| nuclear@7 | 11 /* setup_selectors(uint16_t code, uint16_t data) |
| nuclear@7 | 12 * loads the requested selectors to all the selector registers */ |
| nuclear@7 | 13 .globl setup_selectors |
| nuclear@7 | 14 setup_selectors: |
| nuclear@8 | 15 /* set data selectors directly */ |
| nuclear@7 | 16 movl 8(%esp), %eax |
| nuclear@7 | 17 movw %ax, %ss |
| nuclear@7 | 18 movw %ax, %es |
| nuclear@7 | 19 movw %ax, %ds |
| nuclear@7 | 20 movw %ax, %gs |
| nuclear@7 | 21 movw %ax, %fs |
| nuclear@8 | 22 /* set cs using a long jump */ |
| nuclear@7 | 23 movl 4(%esp), %eax |
| nuclear@7 | 24 movw %ax, (seg) |
| nuclear@7 | 25 movl $ldcs, (off) |
| nuclear@7 | 26 ljmp *off |
| nuclear@7 | 27 ldcs: |
| nuclear@7 | 28 ret |
| nuclear@7 | 29 |
| nuclear@7 | 30 /* set_gdt(uint32_t addr, uint16_t limit) |
| nuclear@7 | 31 * loads the GDTR with the new address and limit for the GDT */ |
| nuclear@7 | 32 .globl set_gdt |
| nuclear@7 | 33 set_gdt: |
| nuclear@7 | 34 movl 4(%esp), %eax |
| nuclear@8 | 35 movl %eax, (addr) |
| nuclear@7 | 36 movw 8(%esp), %ax |
| nuclear@8 | 37 movw %ax, (lim) |
| nuclear@8 | 38 lgdt (lim) |
| nuclear@7 | 39 ret |
| nuclear@54 | 40 |
| nuclear@54 | 41 /* set_task_reg(uint16_t tss_selector) |
| nuclear@54 | 42 * loads the TSS selector in the task register */ |
| nuclear@54 | 43 .globl set_task_reg |
| nuclear@54 | 44 set_task_reg: |
| nuclear@55 | 45 mov 4(%esp), %eax |
| nuclear@54 | 46 ltr 4(%esp) |
| nuclear@54 | 47 ret |