The QEMU fw_cfg interface allows the guest to retrieve various data information from QEMU. For example, APCI/SMBios tables, number of online cpus, kernel data and command line, etc.
This patch adds support for QEMU fw_cfg interface.
Signed-off-by: Miao Yan yanmiaobest@gmail.com Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com --- Changes in v5: - change 'fw' to 'qfw' - move fw_cfg.h to include/asm - cleanups
arch/x86/cpu/qemu/Makefile | 2 +- arch/x86/cpu/qemu/fw_cfg.c | 286 ++++++++++++++++++++++++++++++++++++++++++ arch/x86/cpu/qemu/qemu.c | 3 + arch/x86/include/asm/fw_cfg.h | 95 ++++++++++++++ 4 files changed, 385 insertions(+), 1 deletion(-) create mode 100644 arch/x86/cpu/qemu/fw_cfg.c create mode 100644 arch/x86/include/asm/fw_cfg.h
diff --git a/arch/x86/cpu/qemu/Makefile b/arch/x86/cpu/qemu/Makefile index 3f3958a..d613798 100644 --- a/arch/x86/cpu/qemu/Makefile +++ b/arch/x86/cpu/qemu/Makefile @@ -7,5 +7,5 @@ ifndef CONFIG_EFI_STUB obj-y += car.o dram.o endif -obj-y += qemu.o +obj-y += fw_cfg.o qemu.o obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi.o dsdt.o diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c new file mode 100644 index 0000000..17276c3 --- /dev/null +++ b/arch/x86/cpu/qemu/fw_cfg.c @@ -0,0 +1,286 @@ +/* + * (C) Copyright 2015 Miao Yan yanmiaoebst@gmail.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <command.h> +#include <errno.h> +#include <malloc.h> +#include <asm/io.h> +#include <asm/fw_cfg.h> + +static bool fwcfg_present; +static bool fwcfg_dma_present; + +/* + * Read configuration item using fw_cfg PIO interface + */ + +static void qemu_fwcfg_read_entry_pio(uint16_t entry, + uint32_t size, void *address) +{ + uint32_t i = 0; + uint8_t *data = address; + + /* + * writting FW_CFG_INVALID will cause read operation to resume at + * last offset, otherwise read will start at offset 0 + */ + + if (entry != FW_CFG_INVALID) + outw(entry, FW_CONTROL_PORT); + while (size--) + data[i++] = inb(FW_DATA_PORT); +} + +/* + * Read configuration item using fw_cfg DMA interface + */ + +static void qemu_fwcfg_read_entry_dma(uint16_t entry, + uint32_t size, void *address) +{ + struct fw_cfg_dma_access dma; + + dma.length = cpu_to_be32(size); + dma.address = cpu_to_be64((uintptr_t)address); + dma.control = cpu_to_be32(FW_CFG_DMA_READ); + + /* + * writting FW_CFG_INVALID will cause read operation to resume at + * last offset, otherwise read will start at offset 0 + */ + + if (entry != FW_CFG_INVALID) + dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16)); + + barrier(); + + debug("qemu_fwcfg_dma_read_entry: addr %p, length %u control 0x%x\n", + address, size, be32_to_cpu(dma.control)); + + outl(cpu_to_be32((uint32_t)&dma), FW_DMA_PORT_HIGH); + + while (be32_to_cpu(dma.control) & ~FW_CFG_DMA_ERROR) + __asm__ __volatile__ ("pause"); +} + +static bool qemu_fwcfg_present(void) +{ + uint32_t qemu; + + qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu); + return be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE; +} + +static bool qemu_fwcfg_dma_present(void) +{ + uint8_t dma_enabled; + + qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled); + if (dma_enabled & FW_CFG_DMA_ENABLED) + return true; + + return false; +} + +static void qemu_fwcfg_read_entry(uint16_t entry, + uint32_t length, void *address) +{ + if (fwcfg_dma_present) + qemu_fwcfg_read_entry_dma(entry, length, address); + else + qemu_fwcfg_read_entry_pio(entry, length, address); +} + +int qemu_fwcfg_online_cpus(void) +{ + uint16_t nb_cpus; + + if (!fwcfg_present) + return -ENODEV; + + qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus); + + return le16_to_cpu(nb_cpus); +} + +/* + * This function prepares kernel for zboot. It loads kernel data + * to 'load_addr', initrd to 'initrd_addr' and kernel command + * line using qemu fw_cfg interface. + */ + +static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr) +{ + char *data_addr; + uint32_t setup_size, kernel_size, cmdline_size, initrd_size; + + qemu_fwcfg_read_entry(FW_CFG_SETUP_SIZE, 4, &setup_size); + qemu_fwcfg_read_entry(FW_CFG_KERNEL_SIZE, 4, &kernel_size); + + if (setup_size == 0 || kernel_size == 0) { + printf("warning: no kernel available\n"); + return -1; + } + + data_addr = load_addr; + qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA, + le32_to_cpu(setup_size), data_addr); + data_addr += le32_to_cpu(setup_size); + + qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA, + le32_to_cpu(kernel_size), data_addr); + data_addr += le32_to_cpu(kernel_size); + + data_addr = initrd_addr; + qemu_fwcfg_read_entry(FW_CFG_INITRD_SIZE, 4, &initrd_size); + if (initrd_size == 0) { + printf("warning: no initrd available\n"); + } else { + qemu_fwcfg_read_entry(FW_CFG_INITRD_DATA, + le32_to_cpu(initrd_size), data_addr); + data_addr += le32_to_cpu(initrd_size); + } + + qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size); + if (cmdline_size) { + qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA, + le32_to_cpu(cmdline_size), data_addr); + if (setenv("bootargs", data_addr) < 0) + printf("warning: unable to change bootargs\n"); + } + + printf("loading kernel to address %p size %x", load_addr, + le32_to_cpu(kernel_size)); + if (initrd_size) + printf(" initrd %p size %x\n", + initrd_addr, + le32_to_cpu(initrd_size)); + else + printf("\n"); + + return 0; +} + +static int qemu_fwcfg_list_firmware(void) +{ + int i; + uint32_t count; + struct fw_cfg_files *files; + + qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count); + if (!count) + return 0; + + count = be32_to_cpu(count); + files = malloc(count * sizeof(struct fw_cfg_file)); + if (!files) + return -ENOMEM; + + files->count = count; + qemu_fwcfg_read_entry(FW_CFG_INVALID, + count * sizeof(struct fw_cfg_file), + files->files); + + for (i = 0; i < files->count; i++) + printf("%-56s\n", files->files[i].name); + free(files); + return 0; +} + +void qemu_fwcfg_init(void) +{ + fwcfg_present = qemu_fwcfg_present(); + if (fwcfg_present) + fwcfg_dma_present = qemu_fwcfg_dma_present(); +} + +static int qemu_fwcfg_do_list(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + if (qemu_fwcfg_list_firmware() < 0) + return CMD_RET_FAILURE; + + return 0; +} + +static int qemu_fwcfg_do_cpus(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + int ret = qemu_fwcfg_online_cpus(); + if (ret < 0) { + printf("QEMU fw_cfg interface not found\n"); + return CMD_RET_FAILURE; + } + + printf("%d cpu(s) online\n", qemu_fwcfg_online_cpus()); + + return 0; +} + +static int qemu_fwcfg_do_load(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + char *env; + void *load_addr; + void *initrd_addr; + + env = getenv("loadaddr"); + load_addr = env ? + (void *)simple_strtoul(env, NULL, 16) : + (void *)CONFIG_LOADADDR; + + env = getenv("ramdiskaddr"); + initrd_addr = env ? + (void *)simple_strtoul(env, NULL, 16) : + (void *)CONFIG_RAMDISK_ADDR; + + if (argc == 2) { + load_addr = (void *)simple_strtoul(argv[0], NULL, 16); + initrd_addr = (void *)simple_strtoul(argv[1], NULL, 16); + } else if (argc == 1) { + load_addr = (void *)simple_strtoul(argv[0], NULL, 16); + } + + return qemu_fwcfg_setup_kernel(load_addr, initrd_addr); +} + +static cmd_tbl_t fwcfg_commands[] = { + U_BOOT_CMD_MKENT(list, 0, 1, qemu_fwcfg_do_list, "", ""), + U_BOOT_CMD_MKENT(cpus, 0, 1, qemu_fwcfg_do_cpus, "", ""), + U_BOOT_CMD_MKENT(load, 2, 1, qemu_fwcfg_do_load, "", ""), +}; + +static int do_qemu_fw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{ + int ret; + cmd_tbl_t *fwcfg_cmd; + + if (!fwcfg_present) { + printf("QEMU fw_cfg interface not found\n"); + return CMD_RET_USAGE; + } + + fwcfg_cmd = find_cmd_tbl(argv[1], fwcfg_commands, + ARRAY_SIZE(fwcfg_commands)); + argc -= 2; + argv += 2; + if (!fwcfg_cmd || argc > fwcfg_cmd->maxargs) + return CMD_RET_USAGE; + + ret = fwcfg_cmd->cmd(fwcfg_cmd, flag, argc, argv); + + return cmd_process_error(fwcfg_cmd, ret); +} + +U_BOOT_CMD( + qfw, 4, 1, do_qemu_fw, + "QEMU firmware interface", + "<command>\n" + " - list : print firmware(s) currently loaded\n" + " - cpus : print online cpu number\n" + " - load <kernel addr> <initrd addr> : load kernel and initrd (if any), and setup for zboot\n" +) diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c index 1f93f72..46111c9 100644 --- a/arch/x86/cpu/qemu/qemu.c +++ b/arch/x86/cpu/qemu/qemu.c @@ -11,6 +11,7 @@ #include <asm/processor.h> #include <asm/arch/device.h> #include <asm/arch/qemu.h> +#include <asm/fw_cfg.h>
static bool i440fx;
@@ -57,6 +58,8 @@ static void qemu_chipset_init(void) x86_pci_write_config32(PCI_BDF(0, 0, 0), PCIEX_BAR, CONFIG_PCIE_ECAM_BASE | BAR_EN); } + + qemu_fwcfg_init(); }
int arch_cpu_init(void) diff --git a/arch/x86/include/asm/fw_cfg.h b/arch/x86/include/asm/fw_cfg.h new file mode 100644 index 0000000..18ab3fc --- /dev/null +++ b/arch/x86/include/asm/fw_cfg.h @@ -0,0 +1,95 @@ +/* + * (C) Copyright 2015 Miao Yan yanmiaobest@gmail.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __FW_CFG__ +#define __FW_CFG__ + +#define FW_CONTROL_PORT 0x510 +#define FW_DATA_PORT 0x511 +#define FW_DMA_PORT_LOW 0x514 +#define FW_DMA_PORT_HIGH 0x518 + +enum qemu_fwcfg_items { + FW_CFG_SIGNATURE = 0x00, + FW_CFG_ID = 0x01, + FW_CFG_UUID = 0x02, + FW_CFG_RAM_SIZE = 0x03, + FW_CFG_NOGRAPHIC = 0x04, + FW_CFG_NB_CPUS = 0x05, + FW_CFG_MACHINE_ID = 0x06, + FW_CFG_KERNEL_ADDR = 0x07, + FW_CFG_KERNEL_SIZE = 0x08, + FW_CFG_KERNEL_CMDLINE = 0x09, + FW_CFG_INITRD_ADDR = 0x0a, + FW_CFG_INITRD_SIZE = 0x0b, + FW_CFG_BOOT_DEVICE = 0x0c, + FW_CFG_NUMA = 0x0d, + FW_CFG_BOOT_MENU = 0x0e, + FW_CFG_MAX_CPUS = 0x0f, + FW_CFG_KERNEL_ENTRY = 0x10, + FW_CFG_KERNEL_DATA = 0x11, + FW_CFG_INITRD_DATA = 0x12, + FW_CFG_CMDLINE_ADDR = 0x13, + FW_CFG_CMDLINE_SIZE = 0x14, + FW_CFG_CMDLINE_DATA = 0x15, + FW_CFG_SETUP_ADDR = 0x16, + FW_CFG_SETUP_SIZE = 0x17, + FW_CFG_SETUP_DATA = 0x18, + FW_CFG_FILE_DIR = 0x19, + FW_CFG_FILE_FIRST = 0x20, + FW_CFG_WRITE_CHANNEL = 0x4000, + FW_CFG_ARCH_LOCAL = 0x8000, + FW_CFG_INVALID = 0xffff, +}; + +#define FW_CFG_FILE_SLOTS 0x10 +#define FW_CFG_MAX_ENTRY (FW_CFG_FILE_FIRST + FW_CFG_FILE_SLOTS) +#define FW_CFG_ENTRY_MASK ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL) + +#define FW_CFG_MAX_FILE_PATH 56 + +#define QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U') + +#define FW_CFG_DMA_ERROR (1 << 0) +#define FW_CFG_DMA_READ (1 << 1) +#define FW_CFG_DMA_SKIP (1 << 2) +#define FW_CFG_DMA_SELECT (1 << 3) + +#define FW_CFG_DMA_ENABLED (1 << 1) + +struct fw_cfg_file { + __be32 size; + __be16 select; + __be16 reserved; + char name[FW_CFG_MAX_FILE_PATH]; +}; + +struct fw_cfg_files { + __be32 count; + struct fw_cfg_file files[]; +}; + +struct fw_cfg_dma_access { + __be32 control; + __be32 length; + __be64 address; +}; + +/** + * Initialize QEMU fw_cfg interface + */ + +void qemu_fwcfg_init(void); + +/** + * Get system cpu number + * + * @return: cpu number in system + */ + +int qemu_fwcfg_online_cpus(void); + +#endif