1811fff2dd
Many chips have only one serial port. When the serial port is occupied by other devices, there is a lack of a console to output debugging information. Semihosting can provide a console. The disadvantage of semihosting is that a debugger must be connected, so it can only be used for online debugging. Signed-off-by: ZhongYao Luo <LuoZhongYao@gmail.com> Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
40 lines
734 B
C
40 lines
734 B
C
/*
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* Copyright (c) 2019 LuoZhongYao
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <kernel.h>
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#include <device.h>
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#include <init.h>
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#include <sys/printk.h>
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extern void __printk_hook_install(int (*fn)(int));
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extern void __stdout_hook_install(int (*fn)(int));
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static int semihost_console_out(int ch)
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{
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static unsigned char c;
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c = ch;
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__asm__ __volatile__ (
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"movs r1, %0\n"
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"movs r0, #3\n"
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"bkpt 0xab\n"
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:
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: "r" (&c)
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: "r0", "r1");
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return ch;
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}
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static int semihost_console_init(struct device *dev)
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{
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ARG_UNUSED(dev);
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__printk_hook_install(semihost_console_out);
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__stdout_hook_install(semihost_console_out);
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return 0;
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}
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SYS_INIT(semihost_console_init, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
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