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[/] [openrisc/] [trunk/] [rtos/] [ecos-2.0/] [packages/] [hal/] [powerpc/] [ppc40x/] [v2_0/] [src/] [var_misc.c] - Rev 174
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//========================================================================== // // var_misc.c // // HAL implementation miscellaneous functions // //========================================================================== //####ECOSGPLCOPYRIGHTBEGIN#### // ------------------------------------------- // This file is part of eCos, the Embedded Configurable Operating System. // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc. // // eCos is free software; you can redistribute it and/or modify it under // the terms of the GNU General Public License as published by the Free // Software Foundation; either version 2 or (at your option) any later version. // // eCos is distributed in the hope that it will be useful, but WITHOUT ANY // WARRANTY; without even the implied warranty of MERCHANTABILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License along // with eCos; if not, write to the Free Software Foundation, Inc., // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. // // As a special exception, if other files instantiate templates or use macros // or inline functions from this file, or you compile this file and link it // with other works to produce a work based on this file, this file does not // by itself cause the resulting work to be covered by the GNU General Public // License. However the source code for this file must still be made available // in accordance with section (3) of the GNU General Public License. // // This exception does not invalidate any other reasons why a work based on // this file might be covered by the GNU General Public License. // // Alternative licenses for eCos may be arranged by contacting Red Hat, Inc. // at http://sources.redhat.com/ecos/ecos-license/ // ------------------------------------------- //####ECOSGPLCOPYRIGHTEND#### //========================================================================== //#####DESCRIPTIONBEGIN#### // // Author(s): jskov // Contributors: jskov, gthomas // Date: 2000-02-04 // Purpose: HAL miscellaneous functions // Description: This file contains miscellaneous functions provided by the // HAL. // //####DESCRIPTIONEND#### // //========================================================================== #include <pkgconf/hal.h> #define CYGARC_HAL_COMMON_EXPORT_CPU_MACROS #include <cyg/hal/ppc_regs.h> #include <cyg/infra/cyg_type.h> #include <cyg/hal/hal_mem.h> void hal_ppc40x_clock_initialize(cyg_uint32 period); //-------------------------------------------------------------------------- void hal_variant_init(void) { // Initialize real-time clock (for delays, etc, even if kernel doesn't use it) hal_ppc40x_clock_initialize(CYGNUM_HAL_RTC_PERIOD); } //-------------------------------------------------------------------------- // Variant specific idle thread action. bool hal_variant_idle_thread_action( cyg_uint32 count ) { // Let architecture idle thread action run return true; } //--------------------------------------------------------------------------- // Use MMU resources to map memory regions. // Takes and returns an int used to ID the MMU resource to use. This ID // is increased as resources are used and should be used for subsequent // invocations. // // The PPC4xx CPUs do not have BATs. Fortunately we don't currently // use the MMU, so we can simulate BATs by using the TLBs. int cyg_hal_map_memory (int id, CYG_ADDRESS virt, CYG_ADDRESS phys, cyg_int32 size, cyg_uint8 flags) { cyg_uint32 epn, rpn; int sv, lv, max_tlbs; // There are 64 TLBs. max_tlbs = 64; // Use the smallest "size" value which is big enough (round up) for (sv = 0, lv = 0x400; sv < 8; sv++, lv <<= 2) { if (lv >= size) break; } // Note: the process ID comes from the PID register (always 0) epn = (virt & M_EPN_EPNMASK) | M_EPN_EV | M_EPN_SIZE(sv); rpn = (phys & M_RPN_RPNMASK) | M_RPN_EX | M_RPN_WR; if (flags & CYGARC_MEMDESC_CI) { rpn |= M_RPN_I; } if (flags & CYGARC_MEMDESC_GUARDED) rpn |= M_RPN_G; CYGARC_TLBWE(id, epn, rpn); id++; // Make caches default disabled when MMU is disabled. return id; } // Initialize MMU to a sane (NOP) state. // // Initialize TLBs with 0, Valid bits unset. void cyg_hal_clear_MMU (void) { cyg_uint32 tlbhi = 0; cyg_uint32 tlblo = 0; int id, max_tlbs; // There are 64 TLBs. max_tlbs = 64; CYGARC_MTSPR (SPR_PID, 0); for (id = 0; id < max_tlbs; id++) { CYGARC_TLBWE(id, tlbhi, tlblo); } } //-------------------------------------------------------------------------- // Clock control - use the programmable (variable period) timer static cyg_uint32 _period; extern cyg_uint32 _hold_tcr; // Shadow of TCR register which can't be read void hal_ppc40x_clock_initialize(cyg_uint32 period) { cyg_uint32 tcr; // Enable auto-reload CYGARC_MFSPR(SPR_TCR, tcr); tcr = _hold_tcr; tcr |= TCR_ARE; CYGARC_MTSPR(SPR_TCR, tcr); _hold_tcr = tcr; // Set up the counter register _period = period; CYGARC_MTSPR(SPR_PIT, period); } // Returns the number of clocks since the last interrupt externC void hal_ppc40x_clock_read(cyg_uint32 *val) { cyg_uint32 cur_val; CYGARC_MFSPR(SPR_PIT, cur_val); *val = _period - cur_val; } externC void hal_ppc40x_clock_reset(cyg_uint32 vector, cyg_uint32 period) { hal_ppc40x_clock_initialize(period); } // // Delay for the specified number of microseconds. // Assumption: _period has been set already and corresponds to the // system clock frequency, normally 10ms. // externC void hal_ppc40x_delay_us(int us) { cyg_uint32 delay_period, delay, diff; cyg_uint32 pit_val1, pit_val2; delay_period = (_period * us) / 10000; delay = 0; CYGARC_MFSPR(SPR_PIT, pit_val1); while (delay < delay_period) { // Wait for clock to "tick" while (true) { CYGARC_MFSPR(SPR_PIT, pit_val2); if (pit_val2 != pit_val1) break; } if (pit_val2 > pit_val1) { diff = pit_val2 - pit_val1; } else { diff = (pit_val2 + _period) - pit_val1; } delay += diff; pit_val1 = pit_val2; } } //-------------------------------------------------------------------------- // End of var_misc.c