From 5085f9737b62a7ce4a60ed73f43f801535ebe9f1 Mon Sep 17 00:00:00 2001 From: Daniel Friesel Date: Mon, 27 May 2019 13:52:21 +0200 Subject: Resume execution after power loss --- src/app/transactiontest/main.cc | 4 +++- src/app/transactiontest/util.S | 51 ++++++++++++++++++++++++++--------------- 2 files changed, 36 insertions(+), 19 deletions(-) (limited to 'src/app') 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 -- cgit v1.2.3