FreeCalypso > hg > freecalypso-sw
view target-utils/tf-breakin/payload.S @ 992:a7b0b426f9ca
target-utils: boot ROM UART autodetection revamped
The new implementation should work with both the familiar Calypso C035
boot ROM version found in our regular targets as well as the older
Calypso F741979B version found on the vintage D-Sample board.
author | Mychaela Falconia <falcon@ivan.Harhan.ORG> |
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date | Wed, 30 Dec 2015 21:28:41 +0000 |
parents | 7166c8311b0d |
children |
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.text .org 0 @ allow entry in Thumb state .code 16 bx pc nop .code 32 @ set CPSR like mot931c payload does msr CPSR_c, #0xd3 @ disable the watchdog ldr r1, =0xfffff802 mov r0, #0xf5 strh r0, [r1, #2] mov r0, #0xa0 strh r0, [r1, #2] @ MODEM UART ldr r6, =0xffff5800 @ wait for any previous output to flush out 1: ldrb r0, [r6, #5] tst r0, #0x20 beq 1b @ send our indication adr r1, outstr mov r2, #6 1: ldrb r0, [r1], #1 strb r0, [r6] subs r2, r2, #1 bne 1b @ wait for this output to go out to the TxD pin 1: ldrb r0, [r6, #5] tst r0, #0x40 beq 1b @ enable the Calypso boot ROM ldr r1, =0xFFFFFB10 mov r2, #0x0100 strh r2, [r1] @ jump to it! mov pc, #0 .ltorg outstr: .byte 2,2,2,'O','K',2