FreeCalypso > hg > freecalypso-tools

annotate target-utils/flash-boot-test/uartinit.S @ 926:6a0aa8d36d06

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rvinterf backslash escape: introduce libprint The new helper function library named libprint is meant to replace the badly misnamed libg23, and will soon contain functions for printing all of the same kinds of GPF TST packets that are now handled in libg23. However, we are also moving safe_print_trace() from libasync to this new library, and changing it to emit our new backslash escape format.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 23 May 2023 03:47:46 +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 /*
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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2 * The UART initialization code in this assembly module has been lifted
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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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
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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9 .globl uart_init
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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10
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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11 uart_init:
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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12 stmfd sp!, {r4-r11,lr}
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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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
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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16 mov r10, #7 @ baud rate divisor for 115200 baud
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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17 mov r9, #0x80
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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18 mov r7, #0xbf
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19 mov r4, #7
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20 @ UART base address
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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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
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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40 @ write 07 into FCR: FIFOs enabled and cleared, no DMA
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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41 strb r4, [r1]
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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42 @ write BF into LCR again
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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43 strb r7, [r0]
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44 @ load baud rate divisor
cc6594a7fc7a target-utils/flash-boot-test: added UART init, needed for mode 1
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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}