LibC: Port setjmp syntax to avoid nasm dependency

Author: https://github.com/rburchell
Commit: https://github.com/SerenityOS/serenity/commit/a04a58b7ebb
Pull-request: https://github.com/SerenityOS/serenity/pull/73
Reviewed-by: https://github.com/awesomekling

LibC/Makefile

@@ -48,7 +48,7 @@ LIBC_OBJS = \
        netdb.o \
        sched.o
 
-ASM_OBJS = setjmp.no crti.ao crtn.ao
+ASM_OBJS = setjmp.ao crti.ao crtn.ao
 
 CPP_OBJS = $(AK_OBJS) $(WIDGETS_OBJS) $(LIBC_OBJS)
 
@@ -68,9 +68,6 @@ $(LIBRARY): $(CPP_OBJS) $(ASM_OBJS)
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 
-%.no: %.asm
-	@echo "NASM $@"; nasm -f elf -o $@ $<
-
 %.ao: %.S
 	@echo "AS $@"; $(AS) -o $@ $<
 

LibC/setjmp.S

@@ -0,0 +1,31 @@
+.global setjmp
+setjmp:
+    mov 4(%esp), %eax
+    mov %ebx, 0(%eax)
+    mov %esi, 4(%eax)
+    mov %edi, 8(%eax)
+    mov %ebp, 12(%eax)
+    lea 4(%esp), %ecx
+    mov %ecx, 16(%eax)
+    mov (%esp), %ecx
+    mov %ecx, 20(%eax)
+    xor %eax, %eax
+    ret
+
+.global longjmp
+longjmp:
+    mov 4(%esp), %edx
+    mov 8(%esp), %eax
+    mov 0(%edx), %ebx
+    mov 4(%edx), %esi
+    mov 8(%edx), %edi
+    mov 12(%edx), %ebp
+    mov 16(%edx), %ecx
+    mov %ecx, %esp
+    mov 20(%edx), %ecx
+    test %eax, %eax
+    jnz  .nonzero
+    mov 1, %eax
+.nonzero:
+    jmp *%ecx
+

LibC/setjmp.asm

@@ -1,33 +0,0 @@
-; asmsyntax=nasm
-
-global setjmp
-setjmp:
-    mov eax, [esp + 4]
-    mov [eax + 0 * 4], ebx
-    mov [eax + 1 * 4], esi
-    mov [eax + 2 * 4], edi
-    mov [eax + 3 * 4], ebp
-    lea ecx, [esp + 4]
-    mov [eax + 4 * 4], ecx
-    mov ecx, [esp]
-    mov [eax + 5 * 4], ecx
-    xor eax, eax
-    ret
-
-global longjmp
-longjmp:
-    mov edx, [esp + 4]
-    mov eax, [esp + 8]
-    mov ebx, [edx + 0 * 4]
-    mov esi, [edx + 1 * 4]
-    mov edi, [edx + 2 * 4]
-    mov ebp, [edx + 3 * 4]
-    mov ecx, [edx + 4 * 4]
-    mov esp, ecx
-    mov ecx, [edx + 5 * 4]
-    test eax, eax
-    jnz  .nonzero
-    mov eax, 1
-.nonzero:
-    jmp ecx
-

LibM/Makefile

@@ -13,9 +13,6 @@ $(LIBRARY): $(OBJS)
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 
-%.no: %.asm
-	@echo "NASM $@"; nasm -f elf -o $@ $<
-
 -include $(OBJS:%.o=%.d)
 
 clean:

Meta/BuildInstructions.md

@@ -12,9 +12,9 @@ First off, GCC needs MPFR, MPC and GMP. On Ubuntu, this is as simple as:
 
     sudo apt install libmpfr-dev libmpc-dev libgmp-dev
 
-For Serenity, we will need nasm, e2fsprogs and QEMU:
+For Serenity, we will need e2fsprogs and QEMU:
 
-    sudo apt install nasm e2fsprogs qemu-system-i386
+    sudo apt install e2fsprogs qemu-system-i386
 
 ## Binutils: