Subversion Repositories Kolibri OS

align 4

proc create_ring_buffer stdcall, size:dword, flags:dword

           locals

             buf_ptr  dd ?

           endl

           mov eax, [size]

           test eax, eax

           jz .fail

           add eax, eax

           stdcall alloc_kernel_space, eax

           test eax, eax

           jz .fail

           mov [buf_ptr], eax

           mov ebx, [size]

           shr ebx, 12

           push ebx

           stdcall alloc_pages, ebx

           pop ecx

           test eax, eax

           jz .mm_fail

           or eax, [flags]

           mov edi, [buf_ptr]

           mov ebx, [buf_ptr]

           mov edx, ecx

           shl edx, 2  

           shr edi, 10

@@:

           mov [page_tabs+edi], eax

           mov [page_tabs+edi+edx], eax

           invlpg [ebx]

           invlpg [ebx+esi]

           add eax, 0x1000

           add ebx, 0x1000

           add edi, 4 

           dec ecx

           jnz @B

           mov eax, [buf_ptr]

           ret

.mm_fail:

           stdcall free_kernel_space, [buf_ptr]

           xor eax, eax

.fail:

           ret