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From: chetannanda@gmail.com (Chetan Nanda)
To: linux-arm-kernel@lists.infradead.org
Subject: not able to understand 'icedcc_putc'
Date: Fri, 29 Jan 2010 22:18:55 +0530	[thread overview]
Message-ID: <7f245da81001290848n5630c6b6q68f19369fd0ad5aa@mail.gmail.com> (raw)

Hello,

I am newbie to ARM core. This might be a very silly question, but I am not
able to understand how 'icedcc_putc' function prints a character on console
(UART).

############3
static void icedcc_putc(int ch)
{
    int status, i = 0x4000000;

    do {
        if (--i < 0)
            return;

        asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
    } while (status & 2);

    asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
}
#############

Thanks for your help

~cnanda
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             reply	other threads:[~2010-01-29 16:48 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-29 16:48 Chetan Nanda [this message]
2010-02-02  8:33 ` not able to understand 'icedcc_putc' Uwe Kleine-König
2010-02-02  8:41   ` Chetan Nanda

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