annotate src/segm-asm.S @ 71:c7bd6ec7b946
changed test_proc to modify memory after the fork in order to try out copy-on-write,
by pushing the result of getpid on the stack.
| author |
John Tsiombikas <nuclear@member.fsf.org> |
| date |
Thu, 13 Oct 2011 05:22:35 +0300 |
| parents |
4eaecb14fe31 |
| children |
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| rev |
line source |
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nuclear@7
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1 .data
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nuclear@8
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2 .align 4
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3 /* memory reserved for setup_selectors */
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4 off:.long 0
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5 seg:.short 0
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nuclear@8
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6 /* memory reserved for set_gdt */
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7 lim:.short 0
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8 addr:.long 0
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9
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10 .text
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11 /* setup_selectors(uint16_t code, uint16_t data)
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12 * loads the requested selectors to all the selector registers */
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13 .globl setup_selectors
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14 setup_selectors:
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15 /* set data selectors directly */
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16 movl 8(%esp), %eax
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17 movw %ax, %ss
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18 movw %ax, %es
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19 movw %ax, %ds
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20 movw %ax, %gs
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21 movw %ax, %fs
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22 /* set cs using a long jump */
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23 movl 4(%esp), %eax
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24 movw %ax, (seg)
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25 movl $ldcs, (off)
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26 ljmp *off
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27 ldcs:
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28 ret
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29
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30 /* set_gdt(uint32_t addr, uint16_t limit)
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31 * loads the GDTR with the new address and limit for the GDT */
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32 .globl set_gdt
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33 set_gdt:
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34 movl 4(%esp), %eax
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35 movl %eax, (addr)
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36 movw 8(%esp), %ax
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37 movw %ax, (lim)
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38 lgdt (lim)
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39 ret
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nuclear@54
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40
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nuclear@54
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41 /* set_task_reg(uint16_t tss_selector)
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42 * loads the TSS selector in the task register */
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43 .globl set_task_reg
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44 set_task_reg:
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45 mov 4(%esp), %eax
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46 ltr 4(%esp)
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47 ret
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