rt-thread-official/libcpu/mips/loongson_1b/mipscfg.c

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/*
* File : mipscfg.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2011, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rt-thread.org/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2010-05-27 swkyer first version
*/
#include <rtthread.h>
#include "../common/mipsregs.h"
#include "../common/mipscfg.h"
mips32_core_cfg_t g_mips_core =
{
16, /* icache_line_size */
256, /* icache_lines_per_way */
4, /* icache_ways */
16, /* dcache_line_size */
256, /* dcache_lines_per_way */
4, /* dcache_ways */
16, /* max_tlb_entries */
};
static rt_uint16_t m_pow(rt_uint16_t b, rt_uint16_t n)
{
rt_uint16_t rets = 1;
while (n--)
rets *= b;
return rets;
}
static rt_uint16_t m_log2(rt_uint16_t b)
{
rt_uint16_t rets = 0;
while (b != 1)
{
b /= 2;
rets++;
}
return rets;
}
/**
* read core attribute
*/
void mips32_cfg_init(void)
{
rt_uint16_t val;
rt_uint32_t cp0_config1;
cp0_config1 = read_c0_config();
if (cp0_config1 & 0x80000000)
{
cp0_config1 = read_c0_config1();
val = (cp0_config1 & (7<<22))>>22;
g_mips_core.icache_lines_per_way = 64 * m_pow(2, val);
val = (cp0_config1 & (7<<19))>>19;
g_mips_core.icache_line_size = 2 * m_pow(2, val);
val = (cp0_config1 & (7<<16))>>16;
g_mips_core.icache_ways = val + 1;
val = (cp0_config1 & (7<<13))>>13;
g_mips_core.dcache_lines_per_way = 64 * m_pow(2, val);
val = (cp0_config1 & (7<<10))>>10;
g_mips_core.dcache_line_size = 2 * m_pow(2, val);
val = (cp0_config1 & (7<<7))>>7;
g_mips_core.dcache_ways = val + 1;
val = (cp0_config1 & (0x3F<<25))>>25;
g_mips_core.max_tlb_entries = val + 1;
}
}