[U-Boot] [PATCH 1/7] x86: qemu: add fw_cfg support

Miao Yan yanmiaobest at gmail.com
Mon Dec 28 10:18:26 CET 2015


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 at gmail.com>
---
 arch/x86/cpu/qemu/Makefile |   2 +-
 arch/x86/cpu/qemu/fw_cfg.c | 215 +++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/cpu/qemu/fw_cfg.h |  84 ++++++++++++++++++
 arch/x86/cpu/qemu/qemu.c   |   3 +
 4 files changed, 303 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/cpu/qemu/fw_cfg.c
 create mode 100644 arch/x86/cpu/qemu/fw_cfg.h

diff --git a/arch/x86/cpu/qemu/Makefile b/arch/x86/cpu/qemu/Makefile
index 3f3958a..ad424ec 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 += qemu.o fw_cfg.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..e7615d1
--- /dev/null
+++ b/arch/x86/cpu/qemu/fw_cfg.c
@@ -0,0 +1,215 @@
+/*
+ * (C) Copyright 2015 Miao Yan <yanmiaoebst at gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <environment.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <errno.h>
+#include <fs.h>
+#include <asm/io.h>
+#include "fw_cfg.h"
+
+static bool fwcfg_present;
+static bool fwcfg_dma_present;
+
+static  void qemu_fwcfg_read_entry_pio(uint16_t entry,
+		uint32_t size, void *address)
+{
+	uint32_t i = 0;
+	uint8_t *data = address;
+
+	if (entry != FW_CFG_INVALID)
+		outw(entry, FW_CONTROL_PORT);
+	while (size--)
+		data[i++] = inb(FW_DATA_PORT);
+}
+
+static  void qemu_fwcfg_read_entry_dma(uint16_t entry,
+		uint32_t length, void *address)
+{
+	struct fw_cfg_dma_access dma;
+
+	debug("qemu_fwcfg_dma_read_entry: addr %p, length %u control 0x%x\n",
+	      address, length, dma.control);
+
+	dma.length = cpu_to_be32(length);
+	dma.address = cpu_to_be64((uintptr_t)address);
+	dma.control = cpu_to_be32(FW_CFG_DMA_READ);
+	if (entry != FW_CFG_INVALID)
+		dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
+
+	barrier();
+
+	outl(cpu_to_be32((uint32_t)&dma), FW_DMA_PORT + 4);
+
+	while (dma.control & ~FW_CFG_DMA_ERROR)
+		__asm__ __volatile__ ("rep;nop");
+}
+
+static int 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 int qemu_fwcfg_dma_present(void)
+{
+	uint8_t dma_enabled;
+	uint32_t qemu;
+
+	qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
+	if (dma_enabled & 0x1) {
+		qemu = inl(FW_DMA_PORT);
+		if (be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE)
+			return 1;
+	}
+	return 0;
+}
+
+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);
+}
+
+uint16_t qemu_fwcfg_online_cpus(void)
+{
+	uint16_t nb_cpus;
+	if (!fwcfg_present)
+		return 1;
+
+	qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
+	return nb_cpus;
+}
+
+static int qemu_fwcfg_setup_kernel(void *load_addr)
+{
+	char *cmd_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;
+	}
+	qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA, setup_size, load_addr);
+	qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA, kernel_size,
+			      (char *)load_addr + setup_size);
+
+	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, initrd_size,
+				      (char *)load_addr +
+				      setup_size + kernel_size);
+	}
+
+	qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
+	cmd_addr = (char *)load_addr + setup_size + kernel_size + initrd_size;
+	qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA, cmdline_size, cmd_addr);
+
+	printf("loading kernel to address %p", load_addr);
+	if (initrd_size)
+		printf(" initrd %p\n",
+		       (char *)load_addr + setup_size + kernel_size);
+	else
+		printf("\n");
+
+	return setenv("bootargs", cmd_addr);
+}
+
+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 = false;
+	fwcfg_dma_present = false;
+
+	if (qemu_fwcfg_present()) {
+		fwcfg_present = true;
+		if (qemu_fwcfg_dma_present())
+			fwcfg_dma_present = true;
+	}
+}
+
+int do_qemu_fw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	void *load_addr;
+
+	if (!fwcfg_present) {
+		printf("no qemu fw_cfg found\n");
+		return 0;
+	}
+
+	if (!strncmp(argv[1], "list", 4)) {
+		qemu_fwcfg_list_firmware();
+		return 0;
+	} else if (!strncmp(argv[1], "cpus", 4)) {
+		printf("%u\n", qemu_fwcfg_online_cpus());
+		return 0;
+	} else if (!strncmp(argv[1], "load", 4)) {
+		if (argc == 3) {
+			load_addr = (void *)simple_strtoul(argv[2], NULL, 16);
+		} else {
+			load_addr = getenv("loadaddr");
+			if (!load_addr)
+				load_addr = (void *)CONFIG_SYS_LOAD_ADDR;
+			else
+				load_addr = (void *)simple_strtoul(load_addr,
+								   NULL, 16);
+		}
+
+		return qemu_fwcfg_setup_kernel(load_addr);
+
+	} else {
+		return -1;
+	}
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	fw,	3,	1,	do_qemu_fw,
+	"qemu firmware interface",
+	"<command>\n"
+	"    - list        : print firmware(s) currently loaded\n"
+	"    - cpus        : print online cpu number\n"
+	"    - load <addr> : load kernel (if any) to address <addr>, and setup for zboot\n"
+)
diff --git a/arch/x86/cpu/qemu/fw_cfg.h b/arch/x86/cpu/qemu/fw_cfg.h
new file mode 100644
index 0000000..66e0c8a
--- /dev/null
+++ b/arch/x86/cpu/qemu/fw_cfg.h
@@ -0,0 +1,84 @@
+/*
+ * (C) Copyright 2015 Miao Yan <yanmiaobest at gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __FW_CFG__
+#define __FW_CFG__
+
+#include <common.h>
+#include <asm/io.h>
+
+#define FW_CONTROL_PORT         0x510
+#define FW_DATA_PORT            0x511
+#define FW_DMA_PORT             0x514
+
+#define FW_CFG_SIGNATURE        0x00
+#define FW_CFG_ID               0x01
+#define FW_CFG_UUID             0x02
+#define FW_CFG_RAM_SIZE         0x03
+#define FW_CFG_NOGRAPHIC        0x04
+#define FW_CFG_NB_CPUS          0x05
+#define FW_CFG_MACHINE_ID       0x06
+#define FW_CFG_KERNEL_ADDR      0x07
+#define FW_CFG_KERNEL_SIZE      0x08
+#define FW_CFG_KERNEL_CMDLINE   0x09
+#define FW_CFG_INITRD_ADDR      0x0a
+#define FW_CFG_INITRD_SIZE      0x0b
+#define FW_CFG_BOOT_DEVICE      0x0c
+#define FW_CFG_NUMA             0x0d
+#define FW_CFG_BOOT_MENU        0x0e
+#define FW_CFG_MAX_CPUS         0x0f
+#define FW_CFG_KERNEL_ENTRY     0x10
+#define FW_CFG_KERNEL_DATA      0x11
+#define FW_CFG_INITRD_DATA      0x12
+#define FW_CFG_CMDLINE_ADDR     0x13
+#define FW_CFG_CMDLINE_SIZE     0x14
+#define FW_CFG_CMDLINE_DATA     0x15
+#define FW_CFG_SETUP_ADDR       0x16
+#define FW_CFG_SETUP_SIZE       0x17
+#define FW_CFG_SETUP_DATA       0x18
+#define FW_CFG_FILE_DIR         0x19
+
+#define FW_CFG_FILE_FIRST       0x20
+#define FW_CFG_FILE_SLOTS       0x10
+#define FW_CFG_MAX_ENTRY        (FW_CFG_FILE_FIRST+FW_CFG_FILE_SLOTS)
+
+#define FW_CFG_WRITE_CHANNEL    0x4000
+#define FW_CFG_ARCH_LOCAL       0x8000
+#define FW_CFG_ENTRY_MASK       ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
+
+#define FW_CFG_INVALID          0xffff
+
+#define FW_CFG_MAX_FILE_PATH    56
+
+#define QEMU_FW_CFG_SIGNATURE (('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
+
+#define FW_CFG_DMA_ERROR  (0x1)
+#define FW_CFG_DMA_READ   (0x2)
+#define FW_CFG_DMA_SKIP   (0x4)
+#define FW_CFG_DMA_SELECT (0x8)
+
+struct fw_cfg_file {
+	uint32_t size;
+	uint16_t select;
+	uint16_t 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;
+};
+
+void qemu_fwcfg_init(void);
+uint16_t qemu_fwcfg_online_cpus(void);
+
+#endif
diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c
index 84fb082..c0a79d2 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 "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)
-- 
1.9.1



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