| 37,7 → 37,68 |
|---|
| .global paging_on |
| .global enable_l_apic_in_msr |
| .global interrupt_handlers |
| .global memcpy |
| .global memcpy_from_uspace |
| .global memcpy_from_uspace_failover_address |
| .global memcpy_to_uspace |
| .global memcpy_to_uspace_failover_address |
| |
| |
| #define MEMCPY_DST 4 |
| #define MEMCPY_SRC 8 |
| #define MEMCPY_SIZE 12 |
| |
| /** Copy memory to/from userspace. |
| * |
| * This is almost conventional memcpy(). |
| * The difference is that there is a failover part |
| * to where control is returned from a page fault |
| * if the page fault occurs during copy_from_uspace() |
| * or copy_to_uspace(). |
| * |
| * @param MEMCPY_DST(%esp) Destination address. |
| * @param MEMCPY_SRC(%esp) Source address. |
| * @param MEMCPY_SIZE(%esp) Size. |
| * |
| * @return MEMCPY_SRC(%esp) on success and 0 on failure. |
| */ |
| memcpy: |
| memcpy_from_uspace: |
| memcpy_to_uspace: |
| movl %edi, %edx /* save %edi */ |
| movl %esi, %eax /* save %esi */ |
| |
| movl MEMCPY_SIZE(%esp), %ecx |
| shrl $2, %ecx /* size / 4 */ |
| |
| movl MEMCPY_DST(%esp), %edi |
| movl MEMCPY_SRC(%esp), %esi |
| |
| rep movsl /* copy as much as possible word by word */ |
| |
| movl MEMCPY_SIZE(%esp), %ecx |
| andl $3, %ecx /* size % 4 */ |
| jz 0f |
| |
| rep movsb /* copy the rest byte by byte */ |
| |
| 0: |
| movl %edx, %edi |
| movl %eax, %esi |
| movl MEMCPY_SRC(%esp), %eax /* MEMCPY_SRC(%esp), success */ |
| ret |
| |
| /* |
| * We got here from as_page_fault() after the memory operations |
| * above had caused a page fault. |
| */ |
| memcpy_from_uspace_failover_address: |
| memcpy_to_uspace_failover_address: |
| movl %edx, %edi |
| movl %eax, %esi |
| xorl %eax, %eax /* return 0, failure */ |
| ret |
| |
| ## Turn paging on |
| # |
| # Enable paging and write-back caching in CR0. |