wip: hello world sample

asm-hello-world/Makefile

@@ -0,0 +1,21 @@
+APP_NAME ?= main
+objects  := $(patsubst %.S,%.o,$(wildcard *.S))
+
+default: $(APP_NAME).rim
+
+%.o: %.S
+	pdp1-elf-as $< -o $@
+
+$(APP_NAME).bin: script.ld $(objects)
+	pdp1-elf-ld -o $@ -T $^
+
+%.rim: %.bin
+	pdp1-elf-objcopy -O dec_rim $< $@
+
+run: $(APP_NAME).rim
+	pdp1 startup.pdp1
+
+clean:
+	rm -rf *.o *.bin *.rim
+
+.PHONY: default run clean

asm-hello-world/main.S

@@ -0,0 +1,44 @@
+/* Simple asm program that prints out 'hello, world' on standard output */
+
+.section .data
+i:
+	.byte 0
+ptr:
+	.byte str
+len:
+	.byte end - str
+str:
+	/* TOOD: use .ascii-derived FIODEC directive here */
+	.byte 070
+	.byte 065
+	.byte 043
+	.byte 043
+	.byte 046
+	.byte 033
+	.byte 000
+	.byte 026
+	.byte 046
+	.byte 051
+	.byte 043
+	.byte 064
+	.byte 056
+end:
+
+.section .text
+.global _start
+_start:
+	/* load IO register with *ptr and print it */
+	lio.i ptr
+	tyo
+
+	/* ptr++, i++ */
+	idx ptr
+	idx i
+
+	/* if (i == len) goto _start */
+	lac i
+	sas len
+	jmp _start
+
+	/* halt */
+	hlt

asm-hello-world/script.ld

@@ -0,0 +1,20 @@
+OUTPUT_FORMAT("elf32-pdp1")
+ENTRY(_start)
+
+MEMORY
+{
+	ram (rwx) : ORIGIN = 0x0, LENGTH = 64K
+}
+
+SECTIONS
+{
+	.text :
+	{
+		*(.text)
+	} > ram
+
+	.data 0x400 :
+	{
+		*(.data)
+	} > ram
+}

asm-hello-world/startup.pdp1

@@ -0,0 +1,3 @@
+att ptr main.rim
+boot ptr
+q