/* * Check interraction between cached read/write and ll/sc */ #include #include #include .text .globl _start _start: .set noreorder la k0, TTY_BASE la k1, EXIT_BASE /* reset cop0 status (keep BEV) */ lui a0, 0x0040; mtc0 a0, COP0_STATUS la a0, pte1 srl a0, a0, 13 mtc2 a0, VC_PTPR nop li a0, VC_TLB_EN_ITLB | VC_TLB_EN_DTLB | VC_TLB_EN_ICACHE | VC_TLB_EN_DCACHE mtc2 a0, VC_TLB_EN /* make sure myvar is in cache */ la s1, myvar lw a0, 0(s1) PRINTX PUTCHAR(' ') /* now write to myvar via ll/sc */ la s1, myvar 1: ll a0, 0(s1) li a1, MAGIC2 sc a1, 0(s1) beqz a1, 1b nop PRINTX /* print what we read with ll */ PUTCHAR(' ') la s1, myvar lw a0, 0(s1) /* print the new value */ PRINTX PUTCHAR(' ') /* restore myvar value via normal write */ la s1, myvar li a1, MAGIC1 sw a1, 0(s1) /* read myvar */ lw a0, 0(s1) PRINTX PUTCHAR('\n'); EXIT(0) .globl excep excep: .set noreorder PRINT(statusstr) mfc0 a0, COP0_STATUS PRINTX PRINT(causestr) mfc0 a0, COP0_CAUSE PRINTX PRINT(pcstr) mfc0 a0, COP0_EXPC PRINTX PRINT(badvastr) mfc0 a0, COP_0_BADVADDR PRINTX PUTCHAR('\n') /* we should not get there */ EXIT(1) .rodata: statusstr: .ascii "status \0" causestr: .ascii " cause \0" pcstr: .ascii " pc \0" badvastr: .ascii " badva \0" value: .word 0x1234abcd string: .ascii "hello world \0" .org EXCEP_ADDRESS - BOOT_ADDRESS .globl evect evect: j excep nop .data myvar: .word MAGIC1 .globl pte1 pte1: .align 13 .word PTE1_V | PTE1_W | 0x0 /* map PA 0 at VA 0 */ .org pte1 + (BOOT_ADDRESS >> 21) * 4 .word PTE1_V | PTE1_C | PTE1_X | (BOOT_ADDRESS >> 21) /* map PA 0xbfc00000 at VA 0xbfc00000 */ .org pte1 + (TTY_BASE >> 21) * 4 .word PTE1_V | PTE1_W | (TTY_BASE >> 21) /* map PA 0xd0200000 at VA 0xd0200000 */ .org pte1 + (EXIT_BASE >> 21) * 4 .word PTE1_V | PTE1_W | (EXIT_BASE >> 21) /* map PA 0xe0000000 at VA 0xe0000000 */ .org pte1 + 8192 .word 0