sambuc/rust-arduino-blink-led-no-core-with-cargo
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This commit is contained in:
Jake Goulding
2019-06-16 12:26:39 -04:00
parent 2a01039391
commit 2accfc22a4
3 changed files with 268 additions and 158 deletions
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46
initialize_memory.S
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@@ -4,26 +4,40 @@
;;; Does not handle the region pointer!
__initialize_memory:
ldi r31, hi8(__data_load_start)
ldi r30, lo8(__data_load_start) ; Z
ldi r29, hi8(__data_load_end)
ldi r28, lo8(__data_load_end) ; Y
__initialize_memory_init_data:
ldi r30, lo8(__data_load_start)
ldi r31, hi8(__data_load_start) ; Z
ldi r24, lo8(__data_end)
ldi r25, hi8(__data_end)
ldi r26, lo8(__data_start)
ldi r27, hi8(__data_start) ; X
rjmp __initialize_memory_init_data_check
ldi r27, hi8(__data_start)
ldi r26, lo8(__data_start) ; X
__initialize_memory_init_data_copy:
lpm r18, Z+
st X+, r18
sub r28, r30
sbc r29, r31 ; Y now contains the length of bytes
rjmp check
__initialize_memory_init_data_check:
cp r26, r24
cpc r27, r25
brne __initialize_memory_init_data_copy
entrypoint:
lpm r0, Z+ ; Load from program memory, increment pointer
st X+, r0 ; Store to RAM, increment pointer
__initialize_memory_init_bss:
ldi r24, lo8(__bss_end)
ldi r25, hi8(__bss_end)
ldi r26, lo8(__data_end) ; X
ldi r27, hi8(__data_end)
ldi r18, 0x00
rjmp __initialize_memory_init_bss_check
subi r28, 1 ; Decrement the count
sbci r29, 0
__initialize_memory_init_bss_copy:
st X+, r18
check:
brne entrypoint ; Exit when all bytes copied
__initialize_memory_init_bss_check:
cp r26, r24
cpc r27, r25
brne __initialize_memory_init_bss_copy
__initialize_memory_finish:
ret