| [439] | 1 | /* |
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| 2 | * boot_entry.S - TSAR bootloader entry point. |
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| 3 | * |
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| 4 | * Authors : Alain Greiner / Vu Son (2016) |
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| 5 | * |
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| 6 | * Copyright (c) UPMC Sorbonne Universites |
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| 7 | * |
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| 8 | * This file is part of ALMOS-MKH. |
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| 9 | * |
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| 10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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| 11 | * under the terms of the GNU General Public License as published by |
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| 12 | * the Free Software Foundation; version 2.0 of the License. |
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| 13 | * |
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| 14 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 17 | * General Public License for more details. |
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| 18 | * |
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| 19 | * You should have received a copy of the GNU General Public License |
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| 20 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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| 21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 22 | */ |
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| 23 | |
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| [653] | 24 | /**********************************************************************************************/ |
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| 25 | /* This file contains the entry point of the ALMOS-MK boot-loader for the TSAR architecture, */ |
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| 26 | /* that is a generic multi-clusters / multi-processors architecture. */ |
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| 27 | /* */ |
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| 28 | /* This assembly code is executed by all cores, but not at the same time, because all cores */ |
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| 29 | /* are not simultaneously activated. It makes the assuption that the CPO register containing */ |
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| 30 | /* the core gid (global hardware identifier) has a fixed format: */ |
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| 31 | /* gid == (((x << Y_WIDTH) + y) << P_WIDTH) + lid */ |
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| 32 | /* */ |
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| 33 | /* It does 3 things: */ |
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| 34 | /* - It initializes the stack pointer depending on the lid extracted from the gid, */ |
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| 35 | /* using the BOOT_STACK_BASE and BOOT_STACK_SIZE parameters that are defined in */ |
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| 36 | /* the boot_config.h file, */ |
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| 37 | /* - It changes the value of the DATA address extension register using the cxy extracted */ |
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| 38 | /* from the gid, with X_WIDTH, Y_WIDTH, P_WIDTH defined in the boot¨config.h file. */ |
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| 39 | /* - It jumps to the boot_loader() function defined in the 'boot.c' file, passing the two */ |
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| 40 | /* arguments (cxy and lid). */ |
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| 41 | /**********************************************************************************************/ |
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| [439] | 42 | |
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| 43 | #include "mips32_registers.h" |
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| 44 | #include "boot_config.h" |
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| 45 | |
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| 46 | .section .text, "ax", @progbits |
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| 47 | |
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| 48 | .globl boot_entry |
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| 49 | .ent boot_entry |
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| 50 | |
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| 51 | .align 2 |
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| 52 | .set noreorder |
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| 53 | |
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| 54 | boot_entry: |
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| 55 | |
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| [623] | 56 | /* Get (cxy, lid) values from gid contained in CP0 register */ |
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| [439] | 57 | |
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| 58 | mfc0 k0, CP0_PROCID |
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| 59 | andi k0, k0, 0xFFF /* k0 <= gid */ |
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| 60 | andi t1, k0, ((1 << P_WIDTH) - 1) /* t1 <= lid */ |
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| 61 | srl t2, k0, P_WIDTH /* t2 <= cxy */ |
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| 62 | |
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| [623] | 63 | /* Initialize stack pointer from lid value */ |
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| [439] | 64 | |
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| 65 | la t0, BOOT_STACK_BASE /* t0 <= BOOT_STACK_BASE */ |
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| 66 | li k1, BOOT_STACK_SIZE /* k1 <= BOOT_STACK_SIZE */ |
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| 67 | multu k1, t1 |
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| 68 | mflo k0 /* k0 <= BOOT_STACK_SIZE * lid */ |
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| [623] | 69 | subu sp, t0, k0 /* P[cxy,lid] sp initialized */ |
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| [439] | 70 | |
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| [623] | 71 | /* Switch to local DSPACE by changing the value of the address extension register */ |
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| [439] | 72 | |
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| 73 | mtc2 t2, CP2_DATA_PADDR_EXT |
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| 74 | |
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| [623] | 75 | /* Jump to boot_loader() function after passing (cxy,lid) arguments in the registers */ |
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| [439] | 76 | |
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| 77 | or a0, zero, t1 /* a0 <= lid */ |
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| 78 | or a1, zero, t2 /* a1 <= cxy */ |
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| 79 | la ra, boot_loader |
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| 80 | jr ra |
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| 81 | nop |
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| 82 | |
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| 83 | .end boot_entry |
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| 84 | |
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| 85 | .set reorder |
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