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authorNao Pross <naopross@thearcway.org>2017-11-09 13:17:35 +0100
committerNao Pross <naopross@thearcway.org>2017-11-09 13:17:35 +0100
commit3b2f2ea6c6fbfcb23ea9ab324c83d602d45a8820 (patch)
tree2362bfb36432e551f2f0025d4f12554bddc863c9 /sw/z80/tests/usart/crt0.s
parentUpdate gitignore and add sdcc manual (diff)
downloadz80uPC-3b2f2ea6c6fbfcb23ea9ab324c83d602d45a8820.tar.gz
z80uPC-3b2f2ea6c6fbfcb23ea9ab324c83d602d45a8820.zip
Update makefile, and bug fix in pio driver and usart
Diffstat (limited to '')
-rw-r--r--sw/z80/tests/usart/crt0.s38
1 files changed, 38 insertions, 0 deletions
diff --git a/sw/z80/tests/usart/crt0.s b/sw/z80/tests/usart/crt0.s
new file mode 100644
index 0000000..c900065
--- /dev/null
+++ b/sw/z80/tests/usart/crt0.s
@@ -0,0 +1,38 @@
+ .module crt0
+ .area _HEADER (ABS)
+
+;; Reset vectors
+ .org 0
+ jp init
+
+ .org 0x38 ; the instruction 0xff (not written) resets to this location
+ jp init
+
+;; main code
+ .org 0x100
+ .globl _main
+
+init:
+ ;; Set stack pointer directly above top of memory.
+ ld sp,#0xffff
+
+ ;; Start of the program
+ call _main
+ jp _exit
+
+_exit:
+ halt
+ ; jp _exit
+
+;; Ordering of segments for the linker.
+ .area _HOME
+ .area _CODE
+ .area _INITIALIZER
+ .area _GSINIT
+ .area _GSFINAL
+
+ .area _DATA
+ .area _INITIALIZED
+ .area _BSEG
+ .area _BSS
+ .area _HEAP