From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/cris/boot/rescue/kimagerescue.S | 141 +++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 arch/cris/boot/rescue/kimagerescue.S

(limited to 'arch/cris/boot/rescue/kimagerescue.S')

diff --git a/arch/cris/boot/rescue/kimagerescue.S b/arch/cris/boot/rescue/kimagerescue.S
new file mode 100644
index 000000000..655b511fe
--- /dev/null
+++ b/arch/cris/boot/rescue/kimagerescue.S
@@ -0,0 +1,141 @@
+/*
+ * Rescue code to be prepended on a kimage and copied to the
+ * rescue serial port.
+ * This is called from the rescue code, it will copy received data to
+ * 4004000 and after a timeout jump to it.
+ */
+
+#define ASSEMBLER_MACROS_ONLY
+#include <arch/sv_addr_ag.h>
+
+#define CODE_START 0x40004000
+#define CODE_LENGTH 784
+#define TIMEOUT_VALUE 1000
+
+
+#ifdef CONFIG_ETRAX_RESCUE_SER0
+#define SERXOFF R_SERIAL0_XOFF
+#define SERBAUD R_SERIAL0_BAUD
+#define SERRECC R_SERIAL0_REC_CTRL
+#define SERRDAT R_SERIAL0_REC_DATA
+#define SERSTAT R_SERIAL0_STATUS
+#endif
+#ifdef CONFIG_ETRAX_RESCUE_SER1
+#define SERXOFF R_SERIAL1_XOFF
+#define SERBAUD R_SERIAL1_BAUD
+#define SERRECC R_SERIAL1_REC_CTRL
+#define SERRDAT R_SERIAL1_REC_DATA
+#define SERSTAT R_SERIAL1_STATUS
+#endif
+#ifdef CONFIG_ETRAX_RESCUE_SER2
+#define SERXOFF R_SERIAL2_XOFF
+#define SERBAUD R_SERIAL2_BAUD
+#define SERRECC R_SERIAL2_REC_CTRL
+#define SERRDAT R_SERIAL2_REC_DATA
+#define SERSTAT R_SERIAL2_STATUS
+#endif
+#ifdef CONFIG_ETRAX_RESCUE_SER3
+#define SERXOFF R_SERIAL3_XOFF
+#define SERBAUD R_SERIAL3_BAUD
+#define SERRECC R_SERIAL3_REC_CTRL
+#define SERRDAT R_SERIAL3_REC_DATA
+#define SERSTAT R_SERIAL3_STATUS
+#endif
+
+	.text
+	;; This is the entry point of the rescue code
+	;; 0x80000000 if loaded in flash (as it should be)
+	;; since etrax actually starts at address 2 when booting from flash, we
+	;; put a nop (2 bytes) here first so we dont accidentally skip the di
+
+	nop
+	di
+	;; setup port PA and PB default initial directions and data
+	;; (so we can flash LEDs, and so that DTR and others are set)
+
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0
+	move.b	$r0, [R_PORT_PA_DIR]
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0
+	move.b	$r0, [R_PORT_PA_DATA]
+
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0
+	move.b	$r0, [R_PORT_PB_DIR]
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0
+	move.b	$r0, [R_PORT_PB_DATA]
+
+	;; We need to setup the bus registers before we start using the DRAM
+#include "../../lib/dram_init.S"
+
+	;; Setup the stack to a suitably high address.
+	;; We assume 8 MB is the minimum DRAM in an eLinux
+	;; product and put the sp at the top for now.
+
+	move.d	0x40800000, $sp
+
+	;; setup the serial port at 115200 baud
+
+	moveq	0, $r0
+	move.d	$r0, [SERXOFF]
+
+	move.b	0x99, $r0
+	move.b	$r0, [SERBAUD]		; 115.2kbaud for both transmit
+					; and receive
+
+	move.b	0x40, $r0		; rec enable
+	move.b	$r0, [SERRECC]
+
+
+	moveq	0, $r1			; "timer" to clock out a LED red flash
+	move.d	CODE_START, $r3		; destination counter
+	move.d	CODE_LENGTH, $r4	; length
+	move.d	TIMEOUT_VALUE, $r5	; "timeout" until jump
+
+wait_ser:
+	addq	1, $r1
+	subq	1, $r5			; decrease timeout
+	beq	jump_start		; timed out
+	nop
+#ifndef CONFIG_ETRAX_NO_LEDS
+#ifdef CONFIG_ETRAX_PA_LEDS
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2
+#endif
+#ifdef CONFIG_ETRAX_PB_LEDS
+	move.b	CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2
+#endif
+	move.d	(1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0
+	btstq	16, $r1
+	bpl	1f
+	nop
+	or.d	$r0, $r2		; set bit
+	ba	2f
+	nop
+1:	not	$r0			; clear bit
+	and.d	$r0, $r2
+2:
+#ifdef CONFIG_ETRAX_PA_LEDS
+	move.b	$r2, [R_PORT_PA_DATA]
+#endif
+#ifdef CONFIG_ETRAX_PB_LEDS
+	move.b	$r2, [R_PORT_PB_DATA]
+#endif
+#endif
+
+	;; check if we got something on the serial port
+
+	move.b	[SERSTAT], $r0
+	btstq	0, $r0			; data_avail
+	bpl	wait_ser
+	nop
+
+	;; got something - copy the byte and loop
+
+	move.b	[SERRDAT], $r0
+	move.b	$r0, [$r3+]
+	move.d	TIMEOUT_VALUE, $r5	; reset "timeout"
+	subq	1, $r4			; decrease length
+	bne	wait_ser
+	nop
+jump_start:
+	;; jump into downloaded code
+
+	jump	CODE_START
-- 
cgit v1.2.3-54-g00ecf