/* * 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 #ifndef CONFIG_SVINTO_SIM ;; 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" #endif ;; 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