diff options
Diffstat (limited to 'kernel/arch/cris/boot/rescue/kimagerescue.S')
-rw-r--r-- | kernel/arch/cris/boot/rescue/kimagerescue.S | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/kernel/arch/cris/boot/rescue/kimagerescue.S b/kernel/arch/cris/boot/rescue/kimagerescue.S new file mode 100644 index 000000000..655b511fe --- /dev/null +++ b/kernel/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 |