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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/cris/boot/rescue/kimagerescue.S
Initial import
Diffstat (limited to 'arch/cris/boot/rescue/kimagerescue.S')
-rw-r--r--arch/cris/boot/rescue/kimagerescue.S141
1 files changed, 141 insertions, 0 deletions
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