| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * arch/shmedia/boot/compressed/head.S |
| * |
| * Copied from |
| * arch/shmedia/kernel/head.S |
| * which carried the copyright: |
| * Copyright (C) 2000, 2001 Paolo Alberelli |
| * |
| * Modification for compressed loader: |
| * Copyright (C) 2002 Stuart Menefy (stuart.menefy@st.com) |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/registers.h> |
| #include <asm/cache.h> |
| #include <asm/mmu_context.h> |
| |
| /* |
| * Fixed TLB entries to identity map the beginning of RAM |
| */ |
| #define MMUIR_TEXT_H 0x0000000000000003 | CONFIG_MEMORY_START |
| /* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */ |
| #define MMUIR_TEXT_L 0x000000000000009a | CONFIG_MEMORY_START |
| /* 512 Mb, Cacheable (Write-back), execute, Not User, Ph. Add. */ |
| |
| #define MMUDR_CACHED_H 0x0000000000000003 | CONFIG_MEMORY_START |
| /* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */ |
| #define MMUDR_CACHED_L 0x000000000000015a | CONFIG_MEMORY_START |
| /* 512 Mb, Cacheable (Write-back), read/write, Not User, Ph. Add. */ |
| |
| #define ICCR0_INIT_VAL ICCR0_ON | ICCR0_ICI /* ICE + ICI */ |
| #define ICCR1_INIT_VAL ICCR1_NOLOCK /* No locking */ |
| |
| #if 1 |
| #define OCCR0_INIT_VAL OCCR0_ON | OCCR0_OCI | OCCR0_WB /* OCE + OCI + WB */ |
| #else |
| #define OCCR0_INIT_VAL OCCR0_OFF |
| #endif |
| #define OCCR1_INIT_VAL OCCR1_NOLOCK /* No locking */ |
| |
| .text |
| |
| .global startup |
| startup: |
| /* |
| * Prevent speculative fetch on device memory due to |
| * uninitialized target registers. |
| * This must be executed before the first branch. |
| */ |
| ptabs/u ZERO, tr0 |
| ptabs/u ZERO, tr1 |
| ptabs/u ZERO, tr2 |
| ptabs/u ZERO, tr3 |
| ptabs/u ZERO, tr4 |
| ptabs/u ZERO, tr5 |
| ptabs/u ZERO, tr6 |
| ptabs/u ZERO, tr7 |
| synci |
| |
| /* |
| * Set initial TLB entries for cached and uncached regions. |
| * Note: PTA/BLINK is PIC code, PTABS/BLINK isn't ! |
| */ |
| /* Clear ITLBs */ |
| pta 1f, tr1 |
| movi ITLB_FIXED, r21 |
| movi ITLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22 |
| 1: putcfg r21, 0, ZERO /* Clear MMUIR[n].PTEH.V */ |
| addi r21, TLB_STEP, r21 |
| bne r21, r22, tr1 |
| |
| /* Clear DTLBs */ |
| pta 1f, tr1 |
| movi DTLB_FIXED, r21 |
| movi DTLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22 |
| 1: putcfg r21, 0, ZERO /* Clear MMUDR[n].PTEH.V */ |
| addi r21, TLB_STEP, r21 |
| bne r21, r22, tr1 |
| |
| /* Map one big (512Mb) page for ITLB */ |
| movi ITLB_FIXED, r21 |
| movi MMUIR_TEXT_L, r22 /* PTEL first */ |
| putcfg r21, 1, r22 /* Set MMUIR[0].PTEL */ |
| movi MMUIR_TEXT_H, r22 /* PTEH last */ |
| putcfg r21, 0, r22 /* Set MMUIR[0].PTEH */ |
| |
| /* Map one big CACHED (512Mb) page for DTLB */ |
| movi DTLB_FIXED, r21 |
| movi MMUDR_CACHED_L, r22 /* PTEL first */ |
| putcfg r21, 1, r22 /* Set MMUDR[0].PTEL */ |
| movi MMUDR_CACHED_H, r22 /* PTEH last */ |
| putcfg r21, 0, r22 /* Set MMUDR[0].PTEH */ |
| |
| /* ICache */ |
| movi ICCR_BASE, r21 |
| movi ICCR0_INIT_VAL, r22 |
| movi ICCR1_INIT_VAL, r23 |
| putcfg r21, ICCR_REG0, r22 |
| putcfg r21, ICCR_REG1, r23 |
| synci |
| |
| /* OCache */ |
| movi OCCR_BASE, r21 |
| movi OCCR0_INIT_VAL, r22 |
| movi OCCR1_INIT_VAL, r23 |
| putcfg r21, OCCR_REG0, r22 |
| putcfg r21, OCCR_REG1, r23 |
| synco |
| |
| /* |
| * Enable the MMU. |
| * From here-on code can be non-PIC. |
| */ |
| movi SR_HARMLESS | SR_ENABLE_MMU, r22 |
| putcon r22, SSR |
| movi 1f, r22 |
| putcon r22, SPC |
| synco |
| rte /* And now go into the hyperspace ... */ |
| 1: /* ... that's the next instruction ! */ |
| |
| /* Set initial stack pointer */ |
| movi datalabel stack_start, r0 |
| ld.l r0, 0, r15 |
| |
| /* |
| * Clear bss |
| */ |
| pt 1f, tr1 |
| movi datalabel __bss_start, r22 |
| movi datalabel _end, r23 |
| 1: st.l r22, 0, ZERO |
| addi r22, 4, r22 |
| bne r22, r23, tr1 |
| |
| /* |
| * Decompress the kernel. |
| */ |
| pt decompress_kernel, tr0 |
| blink tr0, r18 |
| |
| /* |
| * Disable the MMU. |
| */ |
| movi SR_HARMLESS, r22 |
| putcon r22, SSR |
| movi 1f, r22 |
| putcon r22, SPC |
| synco |
| rte /* And now go into the hyperspace ... */ |
| 1: /* ... that's the next instruction ! */ |
| |
| /* Jump into the decompressed kernel */ |
| movi datalabel (CONFIG_MEMORY_START + 0x2000)+1, r19 |
| ptabs r19, tr0 |
| blink tr0, r18 |
| |
| /* Shouldn't return here, but just in case, loop forever */ |
| pt 1f, tr0 |
| 1: blink tr0, ZERO |