Change x86 syscalls to direct branches, and define abi for additional syscalls.

Signed-off-by: Scott Wood <scott@thor.buserror.net>

diff --git a/doc/abi/x86 b/doc/abi/x86
index 1f9dbef6a1c6ea93e3bd70ce6f65f4e8ee9f2d5c..7a11bd11a47a813b1a6962e25d1953da52ff9563 100644 (file)
--- a/doc/abi/x86
+++ b/doc/abi/x86
@@ -4,7 +4,7 @@ Out-of-Process Method Invocation:
    Caller:
       eax: pointer to parameter info block (PIB)
 
-      Call the 32-bit address stored at 0x7fff0000 to invoke the method.
+      Call 0x7fff0000 to invoke the method.
       
       Upon return:
       ebx, esi, edi, ebp, esp: preserved
@@ -13,7 +13,7 @@ Out-of-Process Method Invocation:
            function will search for an exception handling function
            that covers the calling address.  If none is found,
            it will assume that it is a language without exception
-           handling, and return the exception to the caller in eax.
+           handling, an5Ad return the exception to the caller in eax.
       edx: length of exception segment, if any
       ecx: may be clobbered
       
@@ -23,9 +23,17 @@ Out-of-Process Method Invocation:
            requested
       esp: NULL.
 
-      Jump to the 32-bit address stored at 0x7fff0004 to return.
+      Jump to 0x7fff0080 to return.
       
       Upon return:
       eax: pointer to exception, or NULL if none
       edx: length of exception segment, if any
-      ebx, esi, edi, ebp, esp: may be clobbered
+      ebx, ecx, esi, edi, ebp, esp: may be clobbered
+
+Other system calls:
+       eax, edx, ecx: syscall arguments.
+       
+       Call 0x7fff0000 + 0x80 * syscallnum
+
+       eax: return value
+       edx, ecx: may be clobbered

diff --git a/kernel/arch/x86/entry.S b/kernel/arch/x86/entry.S
index 997487e2af0437f9b3451cf1911579325e23f7b9..8d4ede48ad2309d117979c0533b7095ca29ff99b 100644 (file)
--- a/kernel/arch/x86/entry.S
+++ b/kernel/arch/x86/entry.S
@@ -14,7 +14,7 @@
 
 #include <arch/addrs.h>
 
-#define ROSHARED_PTR(x) (x - x86_syscall_ptr + 0x7fff0000)
+#define ROSHARED_PTR(x) (x - roshared + 0x7fff0000)
 
        .org 0
        .code32
@@ -406,19 +406,7 @@ arch_new_user_thread:
        iret
 
        .section ".roshared","ax"
-       .align 4096
-       
-       // The vsyscall table must be the first thing in roshared 
-       // (at vaddr 0x7fff0000).
-       
-       .global x86_syscall_ptr
-x86_syscall_ptr:
-       .long   ROSHARED_PTR(x86_shared_int98)
-
-       .global x86_sysret_ptr
-x86_sysret_ptr:
-       .long   ROSHARED_PTR(x86_shared_int99)
-
+roshared:
 x86_shared_int98:
        // FIXME: This must be unpreemptible by traps
        pushl   %gs
@@ -437,12 +425,12 @@ x86_shared_int98_ret:
        popl    %gs
        ret
 
+       . = roshared + 0x80
 x86_shared_int99:
        int     $0x99
        ret
 
        .global test_user_ptr
-       .align 4
 test_user_ptr:
        .long   ROSHARED_PTR(test_user)
        
@@ -459,7 +447,8 @@ test_objlist:
        
 test_user:
        movl    $ROSHARED_PTR(test_pib), %eax
-       call    *0x7fff0000
+       movl    $0x7fff0000, %ecx
+       call    *%ecx
 1:     jmp     1b
 
        .section ".rwshared","a"