Adds thumb directives and fixes for storing the PC

Added directives:
 - .syntax unified at the start of the file
 - .thumb at the start of each code section
 - .thumb_func before each code label

Storing the PC:
 - PC cannot be Rd for str, hence we need the scratch register

1 files changed, 12 insertions, 2 deletions

diff --git a/cgthumb2was.c b/cgthumb2was.c
index 8529878..d43a5ec 100644
--- a/cgthumb2was.c
+++ b/cgthumb2was.c
@@ -92,6 +92,7 @@ static void w_as_to_code_section (VOID)
 {
 	if (in_data_section){
 		in_data_section=0;
+		w_as_instruction_without_parameters (".thumb");
 		w_as_instruction_without_parameters (".text");
 	}
 }
@@ -387,6 +388,7 @@ static void w_as_define_code_label (LABEL *label)
 		w_as_newline();
 	}
 	
+	w_as_instruction_without_parameters (".thumb_func");
 	w_as_label (label->label_name);
 	w_as_colon();
 	w_as_newline();
@@ -1491,15 +1493,21 @@ static void w_as_jsr_instruction (struct instruction *instruction)
 		w_as_newline_after_instruction();
 	} else {
 		if (instruction->instruction_arity>1)
+			w_as_opcode ("mov");
+			w_as_scratch_register_comma();
+			fprintf (assembly_file,"pc");
+			w_as_newline_after_instruction();
 			switch (instruction->instruction_parameters[1].parameter_type){
 				case P_INDIRECT_WITH_UPDATE:
 					w_as_opcode ("str");
-					fprintf (assembly_file,"pc,[sp,#%d]!",instruction->instruction_parameters[1].parameter_offset);
+					w_as_scratch_register_comma();
+					fprintf (assembly_file,"[sp,#%d]!",instruction->instruction_parameters[1].parameter_offset);
 					w_as_newline_after_instruction();
 					break;
 				case P_INDIRECT:
 					w_as_opcode ("str");
-					fprintf (assembly_file,"pc,[sp,#%d]",instruction->instruction_parameters[1].parameter_offset);
+					w_as_scratch_register_comma();
+					fprintf (assembly_file,"[sp,#%d]",instruction->instruction_parameters[1].parameter_offset);
 					w_as_newline_after_instruction();
 					break;
 			}
@@ -2869,6 +2877,8 @@ void write_assembly (VOID)
 	instruction_n_after_ltorg = 0u;
 	ltorg_at_instruction_n = 0u-1u;
 
+	fprintf (assembly_file,"\t.syntax unified");
+	w_as_newline();
 	fprintf (assembly_file,"\t.fpu\tvfp");
 	w_as_newline();