/* * Copyright (c) 2019-2025 Allwinner Technology Co., Ltd. ALL rights reserved. * * Allwinner is a trademark of Allwinner Technology Co.,Ltd., registered in * the the People's Republic of China and other countries. * All Allwinner Technology Co.,Ltd. trademarks are used with permission. * * DISCLAIMER * THIRD PARTY LICENCES MAY BE REQUIRED TO IMPLEMENT THE SOLUTION/PRODUCT. * IF YOU NEED TO INTEGRATE THIRD PARTY’S TECHNOLOGY (SONY, DTS, DOLBY, AVS OR MPEGLA, ETC.) * IN ALLWINNERS’SDK OR PRODUCTS, YOU SHALL BE SOLELY RESPONSIBLE TO OBTAIN * ALL APPROPRIATELY REQUIRED THIRD PARTY LICENCES. * ALLWINNER SHALL HAVE NO WARRANTY, INDEMNITY OR OTHER OBLIGATIONS WITH RESPECT TO MATTERS * COVERED UNDER ANY REQUIRED THIRD PARTY LICENSE. * YOU ARE SOLELY RESPONSIBLE FOR YOUR USAGE OF THIRD PARTY’S TECHNOLOGY. * * * THIS SOFTWARE IS PROVIDED BY ALLWINNER"AS IS" AND TO THE MAXIMUM EXTENT * PERMITTED BY LAW, ALLWINNER EXPRESSLY DISCLAIMS ALL WARRANTIES OF ANY KIND, * WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING WITHOUT LIMITATION REGARDING * THE TITLE, NON-INFRINGEMENT, ACCURACY, CONDITION, COMPLETENESS, PERFORMANCE * OR MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * IN NO EVENT SHALL ALLWINNER 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. */ #include #define HEAP_SIZE (0x10000) .section ".start", "ax", @progbits .align .type start, %function .option norvc start: j 1f .word _magic_sig # 魔数 .word _magic_comp .word _magic_start # zImage 绝对运行地址 .word _magic_end # zImage 结束地址 .word input_data_end - 4 # decompress image size .word 0x04030201 # 结束标志位 1: # mask all interrupts csrw mie, 0 csrw mip, 0 # Enable thead extens li t0, (1 << 22) | (1 << 15) csrs mxstatus, t0 rdtime s8 /* * t0 = 当前pc * t4 = 解压Image 起始地址 * if t0 < t4 : * t0 = LC0[8] = _end - restart + = 当前镜像大小 * t0 = t0 + pc = 当镜像结束地址 * if t4 < t0 :(这种情况会发生自覆盖) * t4 |= 0x1 * else : * bl cache_on * else : * bl cache_on */ #ifdef CONFIG_KERNEL_COMPRESS_ELF la t4, zelfaddr bnez t4, 1f la t0, LC0 lw s0, 0 * 4(t0) # LC0 lw t4, 7 * 4(t0) # .L_user_stack_end sub t0, t0, s0 # calculate the delta offset add t4, t4, t0 li t0, HEAP_SIZE add t4, t4, t0 # 解压到 当前镜像 结束地址 #else la t4, zreladdr #endif 1: auipc t0, 0 bgeu t0, t4, 1f la t1, LC0 lw t2, 8 * 4(t1) auipc t0, 0 add t0, t0, t2 bltu t4, t0, 2f 1: jal cache_on j restart 2: ori t4, t4, 1 # remember we skipped cache_on restart: la t0, LC0 lw s0, 0 * 4(t0) # LC0 lw s1, 1 * 4(t0) # __bss_start lw s2, 2 * 4(t0) # _end lw s3, 3 * 4(t0) # _edata lw s4, 4 * 4(t0) # input+data_end - 4 lw s5, 5 * 4(t0) # _got_start lw s6, 6 * 4(t0) # _got_end lw sp, 7 * 4(t0) # .L_user_stack_end /* * r0 -= r1 计算偏移, 编译地址与运行地址的差值，以此来修正其他符号的地址 * r6 += r0 重新计算_edata, 获得_edata的实际运行地址 * r10 += r0 重新获得压缩后的内核大小数据位置 */ sub t0, t0, s0 # calculate the delta offset add s3, s3, t0 # _edata add s4, s4, t0 # inflated kernel size location /* * 将解压后的内核大小数据正确地放入t1中（避免了大小端问题） */ lbu t1, 0(s4) lbu t2, 1(s4) slli t2, t2, 8 or t1, t1, t2 lbu t2, 2(s4) slli t2, t2, 16 or t1, t1, t2 lbu t2, 3(s4) slli t2, t2, 24 or t1, t1, t2 /* * sp += r0 * s4 = sp + HEAP_SIZE (预留空间出来给作为后续C环境的堆空间) */ add sp, sp, t0 li t5, HEAP_SIZE add s4, sp, t5 /* * 检查是否发生自覆盖. * t4 = 解压后镜像的 起始地址 * t1 = 解压后镜像的 大小 * s4 = 当前镜像的 结束地址, 包含 bss/stack/malloc 空间 * 不发生自覆盖的条件: 16K是MMU的页表大小 * t4 >= s4 -> OK * t4 + t1 <= 当前PC -> OK */ # addi s4, s4, 0x4000 bgeu t4, s4, wont_overwrite add s4, t4, t1 auipc t1, 0 bgeu t1, s4, wont_overwrite /* * 将自己拷贝到 解压后内核的后面. * s3 = _edata 本镜像结束地址 (text+data+bss段,已修正) * s4 = 解压后镜像的结束地址 * Because we always copy ahead, we need to do it from the end and go * backward in case the source and destination overlap. */ /* * 复制到解压后的镜像后 * 对齐到 256B边界 * s4 = ALIGN_UP(s4, 0xff) */ # la t5, ((reloc_code_end - restart + 256) & ~255) la t5, reloc_code_end la t3, restart sub t5, t5, t3 addi t5, t5, 256 li t3, ~0xff and t5, t5, t3 add s4, s4, t5 andi s4, s4, ~0xff /* * 对齐到32B */ la t1, restart andi t1, t1, ~0x1f /* * 自复制 * NOTE: * t1 当前 restart 地址 * s3 当前镜像结束地址 */ sub t2, s3, t1 # size to copy addi t2, t2, 0x1f # rounded up to a multiple andi t2, t2, ~0x1f # ... of 32 bytes add t3, t2, t1 # src t3 add t2, t2, s4 # dst t2 /* * 逐个byte复制,直到 t3 <= t1 * 从后往前复制 */ 1: lw a0, 0 * 4(t3) lw a0, 1 * 4(t3) lw a0, 2 * 4(t3) lw a0, 3 * 4(t3) addi t3, t3, 4 * 4 sw a0, 0 * 4(t2) sw a0, 1 * 4(t2) sw a0, 2 * 4(t2) sw a0, 3 * 4(t2) addi t2, t2, 4 * 4 bgeu t3, t1, 1b /* 保留重定位代码的偏移 */ sub t6, t2, t3 /* cache_clean_flush may use the stack, so relocate it */ add sp, sp, t6 jal cache_clean_flush la t1, restart add t1, t1, t6 jr t1 wont_overwrite: /* * t0 = delta(编译地址与运行地址的差值) * s0 = LC0 * s1 = BSS start * s2 = BSS end * s3 = _edata * s4 = input+data_end - 4 * t4 = 解压后镜像的 起始地址 * s5 = _got_start * s6 = _got_end * sp = .L_user_stack_end */ beqz t0, not_relocated /* 重定位 GOT */ add s5, s5, t0 add s6, s6, t0 /* 重定位 BSS */ add s1, s1, t0 add s2, s2, t0 not_relocated: 1: sw t0, 0(s1) addi s1, s1, 4 bltu s1, s2, 1b /* * 如果前面跳过了 cache_on, t4的最低位=1 * 这里补上 开 cache */ andi t0, t4, 0x1 beqz t0, 2f li t5, 1 sub t4, t4, t5 jal cache_on 2: /* * 准备跳到C执行代码 * a0 = 内核代码的开始地址 */ mv x3, t4 mv a0, t4 mv a1 , sp # free_mem_start li t5, HEAP_SIZE add a2, sp, t5 # free_mem_end mv a3, x0 # architecture ID jal decompress_kernel jal cache_clean_flush #ifdef CONFIG_KERNEL_COMPRESS_ELF mv a0, x3 jal load_elf_image mv a0, x3 jal elf_get_entry_addr mv x3, a0 jal cache_clean_flush #endif jal cache_off mv a0, s8 jr x3 # __enter_kernel .align 5 .type LC0, %object LC0: .word LC0 # s0 .word __bss_start # s1 .word _end # s2 .word _edata # s3 .word input_data_end - 4 # s4 (inflated size location) .word _got_start # s5 .word _got_end # s6 .word .L_user_stack_end # sp .word _end - restart # s7 .size LC0, . - LC0 .align 5 cache_on: li t0, 0x11ff csrw mhcr, t0 li t0, 0x638000 csrw mxstatus, t0 li t0, 0x11ff csrw mhint, t0 fence sync ret cache_off: li t0, 0x3 csrc mhcr, x0 fence sync ret cache_clean_flush: dcache.call icache.iall fence sync ret reloc_code_end: .align 6 .section ".stack", "aw", %nobits .L_user_stack: .space 4096 .L_user_stack_end: