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Diffstat (limited to 'sys/powerpc/ofw/ofwcall64.S')
-rw-r--r-- | sys/powerpc/ofw/ofwcall64.S | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/sys/powerpc/ofw/ofwcall64.S b/sys/powerpc/ofw/ofwcall64.S new file mode 100644 index 0000000..1fb78e8 --- /dev/null +++ b/sys/powerpc/ofw/ofwcall64.S @@ -0,0 +1,290 @@ +/*- + * Copyright (C) 2009-2011 Nathan Whitehorn + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include <sys/syscall.h> + +#include <machine/trap.h> +#include <machine/param.h> +#include <machine/spr.h> +#include <machine/asm.h> + +#define OFWSTKSZ 4096 /* 4K Open Firmware stack */ + +/* + * Globals + */ + .data + .align 4 +ofwstk: + .space OFWSTKSZ +rtas_regsave: + .space 24 /* 3 * sizeof(register_t) */ +GLOBAL(ofmsr) + .llong 0, 0, 0, 0, 0 /* msr/sprg0-3 used in Open Firmware */ +GLOBAL(rtasmsr) + .llong 0 +GLOBAL(openfirmware_entry) + .llong 0 /* Open Firmware entry point */ +GLOBAL(rtas_entry) + .llong 0 /* RTAS entry point */ + +/* + * Open Firmware Real-mode Entry Point. This is a huge pain. + */ + +ASENTRY(ofwcall) + mflr %r0 + std %r0,16(%r1) + stdu %r1,-208(%r1) + + /* + * We need to save the following, because OF's register save/ + * restore code assumes that the contents of registers are + * at most 32 bits wide: lr, cr, r2, r13-r31, the old MSR. These + * get placed in that order in the stack. + */ + + mfcr %r4 + std %r4,48(%r1) + std %r13,56(%r1) + std %r14,64(%r1) + std %r15,72(%r1) + std %r16,80(%r1) + std %r17,88(%r1) + std %r18,96(%r1) + std %r19,104(%r1) + std %r20,112(%r1) + std %r21,120(%r1) + std %r22,128(%r1) + std %r23,136(%r1) + std %r24,144(%r1) + std %r25,152(%r1) + std %r26,160(%r1) + std %r27,168(%r1) + std %r28,176(%r1) + std %r29,184(%r1) + std %r30,192(%r1) + std %r31,200(%r1) + + /* Record the old MSR */ + mfmsr %r6 + + /* read client interface handler */ + lis %r4,openfirmware_entry@ha + ld %r4,openfirmware_entry@l(%r4) + + /* + * Set the MSR to the OF value. This has the side effect of disabling + * exceptions, which is important for the next few steps. + */ + + lis %r5,ofmsr@ha + ld %r5,ofmsr@l(%r5) + mtmsrd %r5 + isync + + /* + * Set up OF stack. This needs to be accessible in real mode and + * use the 32-bit ABI stack frame format. The pointer to the current + * kernel stack is placed at the very top of the stack along with + * the old MSR so we can get them back later. + */ + mr %r5,%r1 + lis %r1,(ofwstk+OFWSTKSZ-32)@ha + addi %r1,%r1,(ofwstk+OFWSTKSZ-32)@l + std %r5,8(%r1) /* Save real stack pointer */ + std %r2,16(%r1) /* Save old TOC */ + std %r6,24(%r1) /* Save old MSR */ + li %r5,0 + stw %r5,4(%r1) + stw %r5,0(%r1) + + /* Finally, branch to OF */ + mtctr %r4 + bctrl + + /* Reload stack pointer and MSR from the OFW stack */ + ld %r6,24(%r1) + ld %r2,16(%r1) + ld %r1,8(%r1) + + /* Now set the real MSR */ + mtmsrd %r6 + isync + + /* Sign-extend the return value from OF */ + extsw %r3,%r3 + + /* Restore all the non-volatile registers */ + ld %r5,48(%r1) + mtcr %r5 + ld %r13,56(%r1) + ld %r14,64(%r1) + ld %r15,72(%r1) + ld %r16,80(%r1) + ld %r17,88(%r1) + ld %r18,96(%r1) + ld %r19,104(%r1) + ld %r20,112(%r1) + ld %r21,120(%r1) + ld %r22,128(%r1) + ld %r23,136(%r1) + ld %r24,144(%r1) + ld %r25,152(%r1) + ld %r26,160(%r1) + ld %r27,168(%r1) + ld %r28,176(%r1) + ld %r29,184(%r1) + ld %r30,192(%r1) + ld %r31,200(%r1) + + /* Restore the stack and link register */ + ld %r1,0(%r1) + ld %r0,16(%r1) + mtlr %r0 + blr + +/* + * RTAS 32-bit Entry Point. Similar to the OF one, but simpler (no separate + * stack) + * + * C prototype: int rtascall(void *callbuffer, void *rtas_privdat); + */ + +ASENTRY(rtascall) + mflr %r0 + std %r0,16(%r1) + stdu %r1,-208(%r1) + + /* + * We need to save the following, because RTAS's register save/ + * restore code assumes that the contents of registers are + * at most 32 bits wide: lr, cr, r2, r13-r31, the old MSR. These + * get placed in that order in the stack. + */ + + mfcr %r5 + std %r5,48(%r1) + std %r13,56(%r1) + std %r14,64(%r1) + std %r15,72(%r1) + std %r16,80(%r1) + std %r17,88(%r1) + std %r18,96(%r1) + std %r19,104(%r1) + std %r20,112(%r1) + std %r21,120(%r1) + std %r22,128(%r1) + std %r23,136(%r1) + std %r24,144(%r1) + std %r25,152(%r1) + std %r26,160(%r1) + std %r27,168(%r1) + std %r28,176(%r1) + std %r29,184(%r1) + std %r30,192(%r1) + std %r31,200(%r1) + + /* Record the old MSR */ + mfmsr %r6 + + /* read client interface handler */ + lis %r5,rtas_entry@ha + ld %r5,rtas_entry@l(%r5) + + /* + * Set the MSR to the RTAS value. This has the side effect of disabling + * exceptions, which is important for the next few steps. + */ + + lis %r7,rtasmsr@ha + ld %r7,rtasmsr@l(%r7) + mtmsrd %r7 + isync + + /* + * Set up RTAS register save area, so that we can get back all of + * our 64-bit pointers. Save our stack pointer, the TOC, and the MSR. + * Put this in r1, since RTAS is obliged to save it. Kernel globals + * are below 4 GB, so this is safe. + */ + mr %r7,%r1 + lis %r1,rtas_regsave@ha + addi %r1,%r1,rtas_regsave@l + std %r7,0(%r1) /* Save 64-bit stack pointer */ + std %r2,8(%r1) /* Save TOC */ + std %r6,16(%r1) /* Save MSR */ + + /* Finally, branch to RTAS */ + mtctr %r5 + bctrl + + /* + * Reload stack pointer and MSR from the reg save area in r1. We are + * running in 32-bit mode at this point, so it doesn't matter if r1 + * has become sign-extended. + */ + ld %r6,16(%r1) + ld %r2,8(%r1) + ld %r1,0(%r1) + + /* Now set the real MSR */ + mtmsrd %r6 + isync + + /* Sign-extend the return value from RTAS */ + extsw %r3,%r3 + + /* Restore all the non-volatile registers */ + ld %r5,48(%r1) + mtcr %r5 + ld %r13,56(%r1) + ld %r14,64(%r1) + ld %r15,72(%r1) + ld %r16,80(%r1) + ld %r17,88(%r1) + ld %r18,96(%r1) + ld %r19,104(%r1) + ld %r20,112(%r1) + ld %r21,120(%r1) + ld %r22,128(%r1) + ld %r23,136(%r1) + ld %r24,144(%r1) + ld %r25,152(%r1) + ld %r26,160(%r1) + ld %r27,168(%r1) + ld %r28,176(%r1) + ld %r29,184(%r1) + ld %r30,192(%r1) + ld %r31,200(%r1) + + /* Restore the stack and link register */ + ld %r1,0(%r1) + ld %r0,16(%r1) + mtlr %r0 + blr + |