Kernel+LibC: Add a dbgputstr() syscall for sending strings to debug output.

This is very handy for the DebugLogStream implementation, among others. :^)

Kernel/Process.cpp

@@ -2722,3 +2722,12 @@ int Process::sys$dbgputch(u8 ch)
     IO::out8(0xe9, ch);
     return 0;
 }
+
+int Process::sys$dbgputstr(const u8* characters, int length)
+{
+    if (!validate_read(characters, length))
+        return -EFAULT;
+    for (int i = 0; i < length; ++i)
+        IO::out8(0xe9, characters[i]);
+    return 0;
+}

Kernel/Process.h

@@ -105,6 +105,7 @@ public:
     void finalize();
 
     int sys$dbgputch(u8);
+    int sys$dbgputstr(const u8*, int length);
     int sys$dump_backtrace();
     int sys$gettid();
     int sys$donate(int tid);

Kernel/Syscall.cpp

@@ -72,6 +72,8 @@ static u32 handle(RegisterDump& regs, u32 function, u32 arg1, u32 arg2, u32 arg3
         break;
     case Syscall::SC_dbgputch:
         return current->process().sys$dbgputch((u8)arg1);
+    case Syscall::SC_dbgputstr:
+        return current->process().sys$dbgputstr((const u8*)arg1, (int)arg2);
     case Syscall::SC_sleep:
         return current->process().sys$sleep((unsigned)arg1);
     case Syscall::SC_usleep:

Kernel/Syscall.h

@@ -117,7 +117,8 @@ struct timeval;
     __ENUMERATE_SYSCALL(halt)                   \
     __ENUMERATE_SYSCALL(reboot)                 \
     __ENUMERATE_SYSCALL(dump_backtrace)         \
-    __ENUMERATE_SYSCALL(dbgputch)
+    __ENUMERATE_SYSCALL(dbgputch)               \
+    __ENUMERATE_SYSCALL(dbgputstr)
 
 namespace Syscall {
 

Kernel/kprintf.cpp

@@ -57,12 +57,18 @@ int ksprintf(char* buffer, const char* fmt, ...)
     return ret;
 }
 
+extern "C" int dbgputstr(const char* characters, int length)
+{
+    for (int i = 0; i < length; ++i)
+        IO::out8(0xe9, characters[i]);
+    return 0;
+}
+
 static void debugger_putch(char*&, char ch)
 {
     IO::out8(0xe9, ch);
 }
 
-
 extern "C" int dbgprintf(const char* fmt, ...)
 {
     color_on();

Kernel/kstdio.h

@@ -1,7 +1,10 @@
 #pragma once
 
+#include <AK/Types.h>
+
 extern "C" {
 int dbgprintf(const char* fmt, ...);
+int dbgputstr(const char*, int);
 int kprintf(const char* fmt, ...);
 int ksprintf(char* buf, const char* fmt, ...);
 }