| 147,6 → 147,45 |
|---|
| popfl |
| .endm |
| |
| /* |
| * The SYSENTER syscall mechanism can be used for syscalls with |
| * four or fewer arguments. To pass these four arguments, we |
| * use four registers: EDX, ECX, EBX, ESI. The syscall number |
| * is passed in EAX. We use EDI to remember the return address |
| * and EBP to remember the stack. The INT-based syscall mechanism |
| * can actually handle six arguments plus the syscall number |
| * entirely in registers. |
| */ |
| .global sysenter_handler |
| sysenter_handler: |
| pushl %ebp # remember user stack |
| pushl %edi # remember return user address |
| |
| pushl %gs # remember TLS |
| |
| pushl %eax # syscall number |
| subl $8, %esp # unused sixth and fifth argument |
| pushl %esi # fourth argument |
| pushl %ebx # third argument |
| pushl %ecx # second argument |
| pushl %edx # first argument |
| |
| movw $16, %ax |
| movw %ax, %ds |
| movw %ax, %es |
| |
| cld |
| call syscall_handler |
| addl $28, %esp # remove arguments from stack |
| |
| pop %gs # restore TLS |
| |
| pop %edx # prepare return EIP for SYSEXIT |
| pop %ecx # prepare userspace ESP for SYSEXIT |
| |
| sysexit # return to userspace |
| |
| |
| ## Declare interrupt handlers |
| # |
| # Declare interrupt handlers for n interrupt |