kport.htm

mips架构的bootloader,99左右的版本 但源代码现在没人更新了

	<title>Porting the SerialICE Kernel</title>
	<h1 align=center>Porting the SerialICE Kernel</h1>

<!--INDEX "SerialICE Port"  -->
<!--INDEX "Porting the SerialICE Kernel" -->

In most cases it will be sufficient to simply change the interrupt
number, and possibly the base address of the SIO. The following code
fragment, which was taken from the SerialICE Kernel for the BDMR4101 shows
where the SIO base address and interrupt input are defined.<p>


<pre>
	#define UART_BASE 	0xbfff0200
	#define UART_RXS	0x0	/* rx status */
	#define UART_RXC	0x0	/* rx control */
	#define UART_RXHR	0x4	/* rx holding reg */
	#define UART_TXS	0x8	/* tx status */
	#define UART_TXHR	0xc	/* tx holding reg */
	#define UART_INTBIT	SR_INT2
</pre>

The SIO on this board is connected to INT2, where the following numbering
is used.<p>

<table border cellpadding=6>
<tr><th>SR bit number</th><th>SR bit name</th><th>Alternate SR bit name</th><th>CAUSE bit name</th><th>Description</th></tr>
<tr><td>8</td><td>SR_IBIT1</td><td>-</td><td>CAUSE_SW1</td><td>Software int1</td></tr>
<tr><td>9</td><td>SR_IBIT2</td><td>-</td><td>CAUSE_SW2</td><td>Software int2</td></tr>
<tr><td>10</td><td>SR_IBIT3</td><td>SR_INT0</td><td>CAUSE_IP3</td><td>Hardware int0</td></tr>
<tr><td>11</td><td>SR_IBIT4</td><td>SR_INT1</td><td>CAUSE_IP4</td><td>Hardware int1</td></tr>
<tr><td>12</td><td>SR_IBIT5</td><td>SR_INT2</td><td>CAUSE_IP5</td><td>Hardware int2</td></tr>
<tr><td>13</td><td>SR_IBIT6</td><td>SR_INT3</td><td>CAUSE_IP6</td><td>Hardware int3</td></tr>
<tr><td>14</td><td>SR_IBIT7</td><td>SR_INT4</td><td>CAUSE_IP7</td><td>Hardware int4</td></tr>
<tr><td>15</td><td>SR_IBIT8</td><td>SR_INT5</td><td>CAUSE_IP8</td><td>Hardware int5</td></tr>
</table><p>

Note that it is recommended that you do <b>not</b> use the non-maskable
interrupt input (even if you have one), because although this will make 
it possible for the SerialICE Kernel to <i>always</i> get control from the
application. It will also make it possible for it to get control at unsafe
times, and therefore not be able to resume the application later.<p>

</dl><p><hr>
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