55 lines
1.1 KiB
C
55 lines
1.1 KiB
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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extern void __stdout_hook_install(int (*fn)(int));
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#define SYS_WRITEC 0x03
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int arch_printk_char_out(int _c)
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{
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char c = _c;
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#if defined(CONFIG_CPU_CORTEX_M)
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register unsigned long r0 __asm__("r0") = SYS_WRITEC;
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register void *r1 __asm__("r1") = &c;
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__asm__ __volatile__ ("bkpt 0xab" : : "r" (r0), "r" (r1) : "memory");
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#elif defined(CONFIG_ARM64)
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register unsigned long x0 __asm__("x0") = SYS_WRITEC;
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register void *x1 __asm__("x1") = &c;
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__asm__ volatile ("hlt 0xf000" : : "r" (x0), "r" (x1) : "memory");
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#else
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#error "unsupported CPU type"
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#endif
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return 0;
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}
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static int semihost_console_init(const struct device *dev)
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{
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ARG_UNUSED(dev);
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/*
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* The printk output callback is arch_printk_char_out by default and
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* is installed at link time. That makes printk() usable very early.
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*
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* We still need to install the stdout callback manually at run time.
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*/
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__stdout_hook_install(arch_printk_char_out);
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return 0;
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}
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SYS_INIT(semihost_console_init, PRE_KERNEL_1, CONFIG_CONSOLE_INIT_PRIORITY);
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