annotate target-utils/flash-boot-test/uartinit.S @ 1011:6d9b10633f10 default tip

etmsync Pirelli IMEI retrieval: fix poor use of printf() Bug reported by Vadim Yanitskiy <fixeria@osmocom.org>: the construct where a static-allocated string was passed to printf() without any format arguments causes newer compilers to report a security problem. Given that formatted output is not needed here, just fixed string output, change printf() to fputs(), and direct the error message to stderr while at it.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 23 May 2024 17:29:57 +0000
parents cc6594a7fc7a
children
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cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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1 /*
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2 * The UART initialization code in this assembly module has been lifted
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3 * from the disassembly of the Calypso boot ROM, and slightly adapted
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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4 * for our needs.
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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5 */
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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6
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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7 .text
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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8 .code 32
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9 .globl uart_init
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10
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11 uart_init:
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12 stmfd sp!, {r4-r11,lr}
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13 @ prepare UART init values
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14 mov r11, #3
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15 mov r5, #0
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16 mov r10, #7 @ baud rate divisor for 115200 baud
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17 mov r9, #0x80
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18 mov r7, #0xbf
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19 mov r4, #7
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20 @ UART base address
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21 ldr r6, =uart_base
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22 ldr r12, [r6]
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23 add r3, r12, #8
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24 @ R3 points to register 8 (MDR1)
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25 @ write 07 into it: reset mode
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26 strb r4, [r3]
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27 add r0, r12, #3
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28 @ R0 points to register 3 (LCR)
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29 @ write BF into it: map in the extended registers
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30 strb r7, [r0]
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31 add r1, r12, #2
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32 @ R1 points to register 2: EFR under current mapping
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33 @ set bit 4: enable enhanced functions
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34 ldrb r8, [r1]
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35 orr r8, r8, #0x10
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36 strb r8, [r1]
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37 @ write 80 into LCR: map in the baud rate divisor registers
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38 strb r9, [r0]
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39 @ reg 2 (pointed to by R1) is now IIR/FCR
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40 @ write 07 into FCR: FIFOs enabled and cleared, no DMA
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41 strb r4, [r1]
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42 @ write BF into LCR again
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43 strb r7, [r0]
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44 @ load baud rate divisor
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45 strb r10, [r12]
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46 strb r5, [r12, #1]
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47 @ write 03 into LCR: restore normal registers, 8N1
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48 strb r11, [r0]
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49 @ write 00 into MDR1: plain UART mode
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50 strb r5, [r3]
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51 ldmfd sp!, {r4-r11,pc}