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