From 0c042601a638c37a95690c6429af5a1b5a35d1dd Mon Sep 17 00:00:00 2001 From: Bibo Mao Date: Sat, 6 Sep 2025 15:01:58 +0800 Subject: [PATCH] hw/loongarch/virt: Add BSP support with aux boot code If system boots directly from Linux kernel, BSP core jumps to kernel entry of Linux kernel image and other APs jump to aux boot code. Instead BSP and APs can all jump to aux boot code like UEFI bios. With aux boot code, BSP core is judged from physical cpu id, whose cpu id is 0. With BSP core, load data to register A0-A2 and PC. Signed-off-by: Bibo Mao Reviewed-by: Song Gao Message-ID: <20250906070200.3749326-2-maobibo@loongson.cn> Signed-off-by: Song Gao --- hw/loongarch/boot.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/hw/loongarch/boot.c b/hw/loongarch/boot.c index 14d6c52d4e4..4962668e5ac 100644 --- a/hw/loongarch/boot.c +++ b/hw/loongarch/boot.c @@ -35,13 +35,19 @@ struct loongarch_linux_hdr { uint32_t pe_header_offset; } QEMU_PACKED; -static const unsigned int slave_boot_code[] = { +static const unsigned int aux_boot_code[] = { /* Configure reset ebase. */ 0x0400302c, /* csrwr $t0, LOONGARCH_CSR_EENTRY */ /* Disable interrupt. */ 0x0380100c, /* ori $t0, $zero,0x4 */ 0x04000180, /* csrxchg $zero, $t0, LOONGARCH_CSR_CRMD */ + 0x03400000, /* nop */ + + 0x0400800c, /* csrrd $t0, LOONGARCH_CSR_CPUNUM */ + 0x034ffd8c, /* andi $t0, $t0, 0x3ff */ + 0x0015000d, /* move $t1, $zero */ + 0x5800718d, /* beq $t0, $t1, 112 */ /* Clear mailbox. */ 0x1400002d, /* lu12i.w $t1, 1(0x1) */ @@ -81,6 +87,26 @@ static const unsigned int slave_boot_code[] = { 0x06480dac, /* iocsrrd.d $t0, $t1 */ 0x00150181, /* move $ra, $t0 */ 0x4c000020, /* jirl $zero, $ra,0 */ + /* BSP Core */ + 0x03400000, /* nop */ + 0x1800000d, /* pcaddi $t1, 0 */ + 0x28c0a1a4, /* ld.d $a0, $t1, 40 */ + 0x1800000d, /* pcaddi $t1, 0 */ + 0x28c0a1a5, /* ld.d $a1, $t1, 40 */ + 0x1800000d, /* pcaddi $t1, 0 */ + 0x28c0a1a6, /* ld.d $a2, $t1, 40 */ + 0x1800000d, /* pcaddi $t1, 0 */ + 0x28c0a1ac, /* ld.d $t0, $t1, 40 */ + 0x00150181, /* move $ra, $t0 */ + 0x4c000020, /* jirl $zero, $ra,0 */ + 0x00000000, /* .dword 0 A0 */ + 0x00000000, + 0x00000000, /* .dword 0 A1 */ + 0x00000000, + 0x00000000, /* .dword 0 A2 */ + 0x00000000, + 0x00000000, /* .dword 0 PC */ + 0x00000000, }; static inline void *guidcpy(void *dst, const void *src) @@ -391,6 +417,7 @@ static void loongarch_direct_kernel_boot(MachineState *ms, int64_t kernel_addr = VIRT_FLASH0_BASE; LoongArchCPU *lacpu; CPUState *cs; + uint64_t *data; if (info->kernel_filename) { kernel_addr = load_kernel_info(info); @@ -408,7 +435,12 @@ static void loongarch_direct_kernel_boot(MachineState *ms, /* Load slave boot code at pflash0 . */ void *boot_code = g_malloc0(VIRT_FLASH0_SIZE); - memcpy(boot_code, &slave_boot_code, sizeof(slave_boot_code)); + memcpy(boot_code, &aux_boot_code, sizeof(aux_boot_code)); + data = (uint64_t *)(boot_code + sizeof(aux_boot_code)); + *(data - 4) = cpu_to_le64(info->a0); + *(data - 3) = cpu_to_le64(info->a1); + *(data - 2) = cpu_to_le64(info->a2); + *(data - 1) = cpu_to_le64(kernel_addr); rom_add_blob_fixed("boot_code", boot_code, VIRT_FLASH0_SIZE, VIRT_FLASH0_BASE); CPU_FOREACH(cs) { -- 2.47.3