libk  Diff

Differences From Artifact [f9a360108d]:

• File kcore/syscall.fn.x86.lin.64.s — part of check-in [37b0cfaa06] at 2019-08-18 17:56:41 on branch trunk — revamp arch/ makefile, add generic syscall fn on posix, rewrite kiosend() to use k_platform_syscall instead of k_platform_write (user: lexi, size: 1781) [annotate] [blame] [check-ins using]

To Artifact [27d79c3e63]:

• File kcore/syscall.fn.x86.lin.64.s — part of check-in [f9bf0d662b] at 2019-08-20 02:03:37 on branch trunk — partially unfuck x86-32, correct major error in syscall ABI (user: lexi, size: 2160) [annotate] [blame] [check-ins using]

    49     49   	%assign i 0
    50     50   	%rep 6
    51     51   		handle_arg i
    52     52   		%assign i i+1
    53     53   	%endrep
    54     54   
    55     55   	; valency >= 7. this is not valid, so
    56         -	; we set our return value to 0 and the
           56  +	; we set our return value to -1 and the
    57     57   	; error number to its maximum value in
    58     58   	; order to indicate that the syscall
    59     59   	; was invalid
    60         -	mov qword [rbx], 0
           60  +	mov qword [rbx], -1
    61     61   	mov qword [r12], -1
    62     62   	ret
    63     63   
    64     64   	; we have a valency match - perform the
    65     65   	; requested syscall already store in rax
    66     66   	.perform_call: sys.call
           67  +
           68  +	; check for an error - on x86, error is
           69  +	; returned as a negative value in %rax
           70  +	test sys.reg.ret, sys.reg.ret
           71  +	js .error ; jump if sign flag set
    67     72   	
    68     73   	; move our return values into place and
    69     74   	; return to the caller (which should
    70     75   	; always be k_platform_syscall, btw)
    71         -	mov [rbx], sys.reg.ret
    72         -	mov [r12], sys.reg.err
           76  +	mov       [rbx], sys.reg.ret
           77  +	mov qword [r12], 0 ; no error
    73     78   	ret
           79  +
           80  +	; an error was returned - we need to set
           81  +	; the errno to its positive equivalent,
           82  +	; and store -1 in the return variable
           83  +	.error: neg sys.reg.ret
           84  +	        mov qword [rbx], -1
           85  +			mov       [r12], sys.reg.ret
           86  +			ret