/* taken from ebfw/rom/dbmentry.s */ #define EB164 /*#ifndef LINT .data .asciiz "$Id: dbmentry.s,v 1.1.1.1 1997/10/30 23:27:12 verghese Exp $" .text #endif */ /* * Debug Monitor Entry code */ #ifndef MAKEDEPEND #include "ev5_impure.h" #include "cserve.h" #include "fromHudsonOsf.h" #endif //#include "paldefs.h" #include "regdefs.h" #include "eb164.h" //#include "ledcodes.h" .text /* return address and padding to octaword align */ #define STARTFRM 16 .globl __start .ent __start, 0 __start: _entry: br t0, 2f # get the current PC 2: ldgp gp, 0(t0) # init gp #ifdef original_xxm lda a2, CSERVE_K_RD_IMPURE call_pal PAL_CSERVE_ENTRY lda v0, CNS_Q_BASE(v0) # Add KSEG offset to the impure area subq zero, 1, t0 sll t0, 42, t0 addq t0, v0, v0 lda t0, CNS_Q_SIGNATURE(v0) bic t0, 0x07, t0 # Clear bottom 3 bits to avoid # allignment errors if the # impure area is total rubbish ldq t0, 0x00(t0) srl t0, 16, t0 # Shift signature into bottom 16 bits. lda t6, 0xDECB(zero) # Load the expected valid signature. zap t6, 0xFC, t6 # Clear the upper bits. cmpeq t0, t6, t0 # Is this a valid signature? beq t0, 1f # Not valid, don't trust input params. /* * Init the stack at the first 8K boundary * below the top of memory. */ lda t0, CNS_Q_MEM_SIZE(v0) ldq t0, 0x00(t0) # Load memory size. subq t0, 1, t0 # Last address in memory srl t0, 13, t0 # Align to first 8KB boundary sll t0, 13, sp # below the top of memory. br zero, 2f /* * If memory size was not passed in via the * PALcode impure data use the system specific * MINIMUM_SYSTEM_MEMORY definition. */ 1: lda sp, (MINIMUM_SYSTEM_MEMORY&0xffff)(zero) ldah sp, ((MINIMUM_SYSTEM_MEMORY+0x8000)>>16)(sp) lda t0, (8*1024)(zero) # Allow for 8KB guard page. subq sp, t0, sp 2: #endif /* original_xxm */ /* * SimOS. Stack pointer is start of a valid phys or KSEG page */ bis sp,sp,s0 /* save sp */ slave: lda v0,(8*1024)(sp) /* end of page */ subq zero, 1, t0 sll t0, 42, t0 bis t0, v0, sp #ifdef original_xxm # Add KSEG offset to the stack pointer subq zero, 1, t0 sll t0, 42, t0 addq t0, sp, sp #endif lda sp, -STARTFRM(sp) # Create a stack frame stq ra, 0(sp) # Place return address on the stack .mask 0x84000000, -8 .frame sp, STARTFRM, ra /* * Enable the Floating Point Unit */ lda a0, 1(zero) call_pal PAL_WRFEN_ENTRY /* * Every good C program has a main() */ beq s0,master call_pal PAL_WHAMI_ENTRY bis v0,v0,a0 jsr ra, SlaveLoop master: jsr ra, main /* * The Debug Monitor should never return. * However, just incase... */ ldgp gp, 0(ra) bsr zero, _exit .end __start .globl _exit .ent _exit, 0 _exit: ldq ra, 0(sp) # restore return address lda sp, STARTFRM(sp) # prune back the stack ret zero, (ra) # Back from whence we came .end _exit .globl cServe .ent cServe 2 cServe: .option O1 .frame sp, 0, ra call_pal PAL_CSERVE_ENTRY ret zero, (ra) .end cServe .globl wrfen .ent wrfen 2 wrfen: .option O1 .frame sp, 0, ra call_pal PAL_WRFEN_ENTRY ret zero, (ra) .end wrfen .globl consoleCallback .ent consoleCallback 2 consoleCallback: br t0, 2f # get the current PC 2: ldgp gp, 0(t0) # init gp lda sp,-64(sp) stq ra,0(sp) jsr CallBackDispatcher ldq ra,0(sp) lda sp,64(sp) ret zero,(ra) .end consoleCallback .globl consoleFixup .ent consoleFixup 2 consoleFixup: br t0, 2f # get the current PC 2: ldgp gp, 0(t0) # init gp lda sp,-64(sp) stq ra,0(sp) jsr CallBackFixup ldq ra,0(sp) lda sp,64(sp) ret zero,(ra) .end consoleFixup .globl SpinLock .ent SpinLock 2 SpinLock: 1: ldq_l a1,0(a0) # interlock complete lock state subl ra,3,v0 # get calling addr[31:0] + 1 blbs a1,2f # branch if lock is busy stq_c v0,0(a0) # attempt to acquire lock beq v0,2f # branch if lost atomicity mb # ensure memory coherence ret zero,(ra) # return to caller (v0 is 1) 2: br zero,1b .end SpinLock