annotate src/vm-asm.S @ 55:88a6c4e192f9
Fixed most important task switching bugs.
Now it seems that I can switch in and out of user space reliably.
| author |
John Tsiombikas <nuclear@member.fsf.org> |
| date |
Mon, 15 Aug 2011 04:03:39 +0300 |
| parents |
387078ef5c0d |
| children |
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| rev |
line source |
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nuclear@17
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1 .text
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nuclear@17
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2 /* enable_paging(void)
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nuclear@26
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3 * sets bit 31 of cr0 which enables page translation */
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4 .globl enable_paging
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5 enable_paging:
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6 movl %cr0, %eax
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7 orl $0x80000000, %eax
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8 movl %eax, %cr0
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9 ret
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10
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11 /* disable_paging(void)
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12 * clears bit 31 of cr0 which disables page translation */
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13 .globl disable_paging
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14 disable_paging:
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15 movl %cr0, %eax
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16 andl $0x7fffffff, %eax
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17 movl %eax, %cr0
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18 ret
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19
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20 /* get_paging_status(void)
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21 * returns 0 if paging is disabled or 1 if it's enabled */
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22 .globl get_paging_status
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23 get_paging_status:
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24 movl %cr0, %eax
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25 shr $31, %eax
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26 ret
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27
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28 /* set_pgdir_addr(uint32_t addr)
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29 * sets the address of the page directory by writing to cr3, which
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30 * also results in a TLB flush. */
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31 .globl set_pgdir_addr
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32 set_pgdir_addr:
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33 movl 4(%esp), %eax
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34 movl %eax, %cr3
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35 ret
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36
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37 /* get_pgdir_addr(void)
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38 * returns the physical address of the page table directory (cr3) */
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39 .globl get_pgdir_addr
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40 get_pgdir_addr:
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41 movl %cr3, %eax
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42 ret
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43
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44 /* flush_tlb(void)
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45 * invalidates the whole TLB. entries for pages marked as global
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46 * are unaffected */
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47 .globl flush_tlb
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48 flush_tlb:
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49 movl %cr3, %eax
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50 movl %eax, %cr3
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51 ret
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52
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53 /* flush_tlb_addr(uint32_t addr)
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54 * flushes the TLB entry for the page containing a particular
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55 * virtual address */
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56 .globl flush_tlb_addr
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57 flush_tlb_addr:
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58 movl 4(%esp), %eax
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59 invlpg (%eax)
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60 ret
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61
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62 /* get_fault_addr(void)
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63 * returns the contents of control register 2, which provides
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64 * the faulting address during a page fault exception
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65 */
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66 .globl get_fault_addr
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67 get_fault_addr:
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68 movl %cr2, %eax
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69 ret
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