diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cpu/amd/model_gx2/cache_as_ram.inc | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/cpu/amd/model_gx2/cache_as_ram.inc b/src/cpu/amd/model_gx2/cache_as_ram.inc new file mode 100644 index 0000000000..09a7541676 --- /dev/null +++ b/src/cpu/amd/model_gx2/cache_as_ram.inc @@ -0,0 +1,207 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2007 Advanced Micro Devices, Inc. + * Copyright (C) 2010 Nils Jacobs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#define GX2_STACK_BASE CONFIG_DCACHE_RAM_BASE /* this is where the DCache will be mapped and be used as stack, It would be cool if it was the same base as coreboot normal stack */ +#define GX2_STACK_END GX2_STACK_BASE+(CONFIG_DCACHE_RAM_SIZE-1) + +#define GX2_NUM_CACHELINES 0x080 /* there are 128lines per way */ +#define GX2_CACHELINE_SIZE 0x020 /* there are 32bytes per line */ +#define GX2_CACHEWAY_SIZE (GX2_NUM_CACHELINES * GX2_CACHELINE_SIZE) +#define CR0_CD 0x40000000 /* bit 30 = Cache Disable */ +#define CR0_NW 0x20000000 /* bit 29 = Not Write Through */ +#include <cpu/amd/gx2def.h> +/*************************************************************************** +/** +/** DCacheSetup +/** +/** Setup data cache for use as RAM for a stack. +/** +/** Max. size data cache =0x4000 (16KB) +/** +/***************************************************************************/ +DCacheSetup: + /* Save the BIST result */ + movl %eax, %ebx + + invd + /* set cache properties */ + movl $CPU_RCONF_DEFAULT, %ecx + rdmsr + movl $0x010010000, %eax /*1MB system memory in write back 1|00100|00 */ + wrmsr + + /* in GX2 DCDIS is set after POR which disables the cache..., clear this bit */ + movl $CPU_DM_CONFIG0, %ecx + rdmsr + andl $(~(DM_CONFIG0_LOWER_DCDIS_SET)), %eax /* TODO: make consistent with i$ init, either whole reg = 0, or just this bit... */ + wrmsr + + /* Get cleaned up. */ + xorl %edi, %edi + xorl %esi, %esi + xorl %ebp, %ebp + + /* DCache Ways0 through Ways3 will be tagged for GX2_STACK_BASE + CONFIG_DCACHE_RAM_SIZE for holding stack */ + /* remember, there is NO stack yet... */ + + /* Tell cache we want to fill WAY 0 starting at the top */ + xorl %edx, %edx + xorl %eax, %eax + movl $CPU_DC_INDEX, %ecx + wrmsr + + /* startaddress for tag of Way0: ebp will hold the incrementing address. dont destroy! */ + movl $GX2_STACK_BASE, %ebp /* init to start address */ + orl $1, %ebp /* set valid bit and tag for this Way (B[31:12] : Cache tag value for line/way curr. selected by CPU_DC_INDEX */ + + /* start tag Ways 0 with 128 lines with 32bytes each: edi will hold the line counter. dont destroy! */ + movl $GX2_NUM_CACHELINES, %edi +DCacheSetupFillWay: + + /* fill with dummy data: zero it so we can tell it from PCI memory space (returns FFs). */ + /* We will now store a line (32 bytes = 4 x 8bytes = 4 quadWords) */ + movw $0x04, %si + xorl %edx, %edx + xorl %eax, %eax + movl $CPU_DC_DATA, %ecx +DCacheSetup_quadWordLoop: + wrmsr + decw %si + jnz DCacheSetup_quadWordLoop + + /* Set the tag for this line,need to do this for every new cache line to validate it! */ + /* accessing CPU_DC_TAG_I makes the LINE field in CPU_DC_INDEX increment and thus cont. in the next cache line... */ + xorl %edx, %edx + movl %ebp, %eax + movl $CPU_DC_TAG, %ecx + wrmsr + + /* switch to next line */ + /* lines are in Bits8:2 */ + /* when index is crossing 0x7F -> 0x80 writing a RSVD bit as 0x80 is not a valid CL anymore! */ + movl $CPU_DC_INDEX, %ecx + rdmsr + addl $0x04, %eax /* inc DC_LINE. TODO: prob. would be more elegant to calc. this from counter var edi... */ + wrmsr + + decl %edi + jnz DCacheSetupFillWay + + /* 1 Way has been filled, forward start address for next Way, terminate if we have reached end of desired address range */ + addl $GX2_CACHEWAY_SIZE, %ebp + cmpl $GX2_STACK_END, %ebp + jge leave_DCacheSetup + movl $GX2_NUM_CACHELINES, %edi + + /* switch to next way */ + movl $CPU_DC_INDEX, %ecx + rdmsr + addl $0x01, %eax + andl $0xFFFFFE03, %eax /* lets be sure: reset line index Bits8:2 */ + wrmsr + + jmp DCacheSetupFillWay + +leave_DCacheSetup: + xorl %edi, %edi + xorl %esi, %esi + xorl %ebp, %ebp + + /* Disable the cache, but ... DO NOT INVALIDATE the tags. */ + /* Memory reads and writes will all hit in the cache. */ + /* Cache updates and memory write-backs will not occur ! */ + movl %cr0, %eax + orl $(CR0_CD + CR0_NW), %eax /* set the CD and NW bits */ + movl %eax, %cr0 + + /* Now point sp to the cached stack. */ + /* The stack will be fully functional at this location. No system memory is required at all ! */ + /* set up the stack pointer */ + movl $GX2_STACK_END, %eax + movl %eax, %esp + + /* test the stack*/ + movl $0x0F0F05A5A, %edx + pushl %edx + popl %ecx + cmpl %ecx, %edx + je DCacheSetupGood + + post_code(0xc5) +DCacheSetupBad: + hlt /* issues */ + jmp DCacheSetupBad +DCacheSetupGood: + /* Go do early init and memory setup */ + + /* Restore the BIST result */ + movl %ebx, %eax + movl %esp, %ebp + pushl %eax + + post_code(0x23) + + /* Call romstage.c main function */ + call main +done_cache_as_ram_main: + + /* We now run over the stack-in-cache, copying it back to itself to invalidate the cache */ + + push %edi + mov $(CONFIG_DCACHE_RAM_SIZE/4),%ecx + push %esi + mov $(CONFIG_DCACHE_RAM_BASE),%edi + mov %edi,%esi + cld + rep movsl %ds:(%esi),%es:(%edi) + pop %esi + pop %edi + + /* Clear the cache out to ram */ + wbinvd + /* re-enable the cache */ + movl %cr0, %eax + xorl $(CR0_CD + CR0_NW), %eax /* clear the CD and NW bits */ + movl %eax, %cr0 + + /* clear boot_complete flag */ + xorl %ebp, %ebp +__main: + post_code(0x11) /* post 11 */ + + /* TODO For suspend/resume the cache will have to live between + * CONFIG_RAMBASE and CONFIG_RAMTOP + */ + + cld /* clear direction flag */ + + /* copy coreboot from it's initial load location to + * the location it is compiled to run at. + * Normally this is copying from FLASH ROM to RAM. + */ + movl %ebp, %esi + pushl %esi + call copy_and_run + +.Lhlt: + post_code(0xee) /* post fail ee */ + hlt + jmp .Lhlt + |