Date: Sat, 11 Nov 2006 20:02:40 -0500 From: Daniel Jacobowitz To: address@hidden Subject: [Qemu-devel] MIPS halt / reboot The MIPS kernel already has a reset/halt device for qemu (arch/mips/qemu/q-reset.c). I have no idea at all where this came from, but hey, it seems sensible enough to me so I implemented it in qemu. This requires a bit of additional mucking around, since MIPS doesn't currently have any BIOS support, so I made the reset vector reload any specified kernel and initrd. Works in my Debian rootfs; very handy for automated benchmarking. -- Daniel Jacobowitz CodeSourcery --- hw/mips_r4k.c | 144 +++++++++++++++++++++++++++++++++--------------- target-mips/cpu.h | 8 ++ target-mips/translate.c | 10 +++ 3 files changed, 116 insertions(+), 46 deletions(-) Index: qemu-work/hw/mips_r4k.c =================================================================== --- qemu-work.orig/hw/mips_r4k.c 2006-11-15 22:40:28.000000000 +0000 +++ qemu-work/hw/mips_r4k.c 2006-11-15 22:41:14.000000000 +0000 @@ -110,6 +110,93 @@ cpu_mips_update_count(env, 1, 0); } +static void mips_qemu_writel (void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + if ((addr & 0xffff) == 0 && val == 42) + qemu_system_reset_request (); + else if ((addr & 0xffff) == 4 && val == 42) + qemu_system_shutdown_request (); +} + +static uint32_t mips_qemu_readl (void *opaque, target_phys_addr_t addr) +{ + return 0; +} + +static CPUWriteMemoryFunc *mips_qemu_write[] = { + &mips_qemu_writel, + &mips_qemu_writel, + &mips_qemu_writel, +}; + +static CPUReadMemoryFunc *mips_qemu_read[] = { + &mips_qemu_readl, + &mips_qemu_readl, + &mips_qemu_readl, +}; + +static int mips_qemu_iomemtype = 0; + +void load_kernel (CPUState *env, int ram_size, const char *kernel_filename, + const char *kernel_cmdline, + const char *initrd_filename) +{ + int64_t entry = 0; + long kernel_size, initrd_size; + + kernel_size = load_elf(kernel_filename, VIRT_TO_PHYS_ADDEND, &entry); + if (kernel_size >= 0) + env->PC = entry; + else { + kernel_size = load_image(kernel_filename, + phys_ram_base + KERNEL_LOAD_ADDR + VIRT_TO_PHYS_ADDEND); + if (kernel_size < 0) { + fprintf(stderr, "qemu: could not load kernel '%s'\n", + kernel_filename); + exit(1); + } + env->PC = KERNEL_LOAD_ADDR; + } + + /* load initrd */ + initrd_size = 0; + if (initrd_filename) { + initrd_size = load_image(initrd_filename, + phys_ram_base + INITRD_LOAD_ADDR + VIRT_TO_PHYS_ADDEND); + if (initrd_size == (target_ulong) -1) { + fprintf(stderr, "qemu: could not load initial ram disk '%s'\n", + initrd_filename); + exit(1); + } + } + + /* Store command line. */ + if (initrd_size > 0) { + int ret; + ret = sprintf(phys_ram_base + (16 << 20) - 256, + "rd_start=0x%08x rd_size=%li ", + INITRD_LOAD_ADDR, + initrd_size); + strcpy (phys_ram_base + (16 << 20) - 256 + ret, kernel_cmdline); + } + else { + strcpy (phys_ram_base + (16 << 20) - 256, kernel_cmdline); + } + + *(int *)(phys_ram_base + (16 << 20) - 260) = tswap32 (0x12345678); + *(int *)(phys_ram_base + (16 << 20) - 264) = tswap32 (ram_size); +} + +static void main_cpu_reset(void *opaque) +{ + CPUState *env = opaque; + cpu_reset(env); + + if (env->kernel_filename) + load_kernel (env, env->ram_size, env->kernel_filename, + env->kernel_cmdline, env->initrd_filename); +} void mips_r4k_init (int ram_size, int vga_ram_size, int boot_device, DisplayState *ds, const char **fd_filename, int snapshot, @@ -117,19 +204,24 @@ const char *initrd_filename) { char buf[1024]; - int64_t entry = 0; unsigned long bios_offset; int ret; CPUState *env; - long kernel_size; int i; env = cpu_init(); register_savevm("cpu", 0, 3, cpu_save, cpu_load, env); + qemu_register_reset(main_cpu_reset, env); /* allocate RAM */ cpu_register_physical_memory(0, ram_size, IO_MEM_RAM); + if (!mips_qemu_iomemtype) { + mips_qemu_iomemtype = cpu_register_io_memory(0, mips_qemu_read, + mips_qemu_write, NULL); + } + cpu_register_physical_memory(0x1fbf0000, 0x10000, mips_qemu_iomemtype); + /* Try to load a BIOS image. If this fails, we continue regardless, but initialize the hardware ourselves. When a kernel gets preloaded we also initialize the hardware, since the BIOS wasn't @@ -146,38 +238,13 @@ buf); } - kernel_size = 0; if (kernel_filename) { - kernel_size = load_elf(kernel_filename, VIRT_TO_PHYS_ADDEND, &entry); - if (kernel_size >= 0) - env->PC = entry; - else { - kernel_size = load_image(kernel_filename, - phys_ram_base + KERNEL_LOAD_ADDR + VIRT_TO_PHYS_ADDEND); - if (kernel_size < 0) { - fprintf(stderr, "qemu: could not load kernel '%s'\n", - kernel_filename); - exit(1); - } - env->PC = KERNEL_LOAD_ADDR; - } - - /* load initrd */ - if (initrd_filename) { - if (load_image(initrd_filename, - phys_ram_base + INITRD_LOAD_ADDR + VIRT_TO_PHYS_ADDEND) - == (target_ulong) -1) { - fprintf(stderr, "qemu: could not load initial ram disk '%s'\n", - initrd_filename); - exit(1); - } - } - - /* Store command line. */ - strcpy (phys_ram_base + (16 << 20) - 256, kernel_cmdline); - /* FIXME: little endian support */ - *(int *)(phys_ram_base + (16 << 20) - 260) = tswap32 (0x12345678); - *(int *)(phys_ram_base + (16 << 20) - 264) = tswap32 (ram_size); + load_kernel (env, ram_size, kernel_filename, kernel_cmdline, + initrd_filename); + env->ram_size = ram_size; + env->kernel_filename = kernel_filename; + env->kernel_cmdline = kernel_cmdline; + env->initrd_filename = initrd_filename; } /* Init internal devices */ Index: qemu-work/target-mips/cpu.h =================================================================== --- qemu-work.orig/target-mips/cpu.h 2006-11-15 22:41:04.000000000 +0000 +++ qemu-work/target-mips/cpu.h 2006-11-15 22:41:14.000000000 +0000 @@ -182,7 +182,6 @@ uint32_t CP0_ErrorEPC; uint32_t CP0_DESAVE; /* Qemu */ - struct QEMUTimer *timer; /* Internal timer */ int interrupt_request; jmp_buf jmp_env; int exception_index; @@ -213,6 +212,13 @@ int halted; /* TRUE if the CPU is in suspend state */ CPU_COMMON + + int ram_size; + const char *kernel_filename; + const char *kernel_cmdline; + const char *initrd_filename; + + struct QEMUTimer *timer; /* Internal timer */ }; #include "cpu-all.h" Index: qemu-work/target-mips/translate.c =================================================================== --- qemu-work.orig/target-mips/translate.c 2006-11-15 22:41:04.000000000 +0000 +++ qemu-work/target-mips/translate.c 2006-11-15 22:41:14.000000000 +0000 @@ -2425,7 +2425,16 @@ if (!env) return NULL; cpu_exec_init(env); + cpu_reset(env); + return env; +} + +void cpu_reset (CPUMIPSState *env) +{ + memset(env, 0, offsetof(CPUMIPSState, breakpoints)); + tlb_flush(env, 1); + /* Minimal init */ env->PC = 0xBFC00000; #if defined (MIPS_USES_R4K_TLB) @@ -2456,5 +2465,4 @@ #ifdef MIPS_USES_FPU env->fcr0 = MIPS_FCR0; #endif - return env; }