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authorDaniel Friesel <daniel.friesel@uos.de>2019-05-27 13:52:21 +0200
committerDaniel Friesel <daniel.friesel@uos.de>2019-05-27 13:52:21 +0200
commit5085f9737b62a7ce4a60ed73f43f801535ebe9f1 (patch)
tree68603fe76709847092979f1f07fd03e36309b173 /src/app
parenta2f5c26a8ac422e9318733fc4d30cef9eb96b3cb (diff)
Resume execution after power loss
Diffstat (limited to 'src/app')
-rw-r--r--src/app/transactiontest/main.cc4
-rw-r--r--src/app/transactiontest/util.S51
2 files changed, 36 insertions, 19 deletions
diff --git a/src/app/transactiontest/main.cc b/src/app/transactiontest/main.cc
index cb2d86e..d0ef9bf 100644
--- a/src/app/transactiontest/main.cc
+++ b/src/app/transactiontest/main.cc
@@ -42,10 +42,12 @@ int main(void)
gpio.setup();
kout.setup();
- //restore_state();
gpio.led_on(0);
gpio.input(GPIO::p4_5, 1);
+
+ asm_load_all();
+
kout << "Hello, World!" << endl;
arch.idle_loop();
diff --git a/src/app/transactiontest/util.S b/src/app/transactiontest/util.S
index c0b1ebc..32744f8 100644
--- a/src/app/transactiontest/util.S
+++ b/src/app/transactiontest/util.S
@@ -8,12 +8,18 @@ stack_backup:
sp_backup:
.space 2
+backup_cookie:
+ .space 2
+
asm_save_all:
dint
.irp reg,4,5,6,7,8,9,10,11
push r\reg
.endr
+ mov #1234h, r10
+ mov r10, &backup_cookie
+
mov r1, &sp_backup
mov #1c00h, r10
@@ -34,6 +40,15 @@ save_sram_word:
asm_load_all:
dint
+ push r11
+ mov &backup_cookie, r11
+ cmp #1234h, r11
+ jeq do_load_all
+ pop r11
+ eint
+ ret
+
+do_load_all:
; restore SRAM from backup
mov #stack_backup, r10
mov #1c00h, r11
@@ -59,32 +74,32 @@ load_sram_word:
asm_load_mem:
dint
- ; save return address in r4
- mov @r1, r4
- ; restore SRAM from backup
+ push r11
+ mov &backup_cookie, r11
+ cmp #1234h, r11
+ jeq do_load_mem
+ pop r11
+ eint
+ ret
+
+do_load_mem:
+ push r10
+ push r9
+ ; restore SRAM from backup, excluding current stack frame
+ mov r1, r9
+ sub 6, r9
mov #stack_backup, r10
mov #1c00h, r11
load_sram_word2:
mov @r10+, 0(r11)
add #2, r11
- cmp #1c00h+2048, r11
+ cmp r9, r11
jlo load_sram_word2
- ; restore stack pointer
- mov &sp_backup, r1
-
- ; restore old register contents
- .irp reg,11,10,9,8,7,6,5
- pop r\reg
- .endr
-
- ; load return address, that is, the address this function was called from.
- ; This is not the address which called asm_save_all -- we only want to restore memory contents, not re-execute everything
- mov r4, 2(r1)
-
- ; load remaining register content
- pop r4
+ pop r9
+ pop r10
+ pop r11
eint
ret