FreeCalypso > hg > freecalypso-tools
view target-utils/tf-breakin/payload.S @ 965:2969032bdfac
fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing
The only 100% safe way to pass a NULL pointer as a function argument
in K&R C is to cast 0 to a pointer type; failing to do so may cause
mysterious bugs (invalid stack frames or garbage in argument registers)
on 64-bit machines. This issue has already been fixed in most of
FC host tools, but I just found some missed spots: passing of NULL UDH
to PDU encoding functions in fcup-smsend[mult] in the case of single
(not concatenated) SMS.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Fri, 01 Sep 2023 07:33:51 +0000 |
| parents | e7502631a0f9 |
| 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