qfw: Add a subcommand to read a QEMU file into memory

Provide a simple command to read a named file into memory.

Skip this test on sandbox for now, as it doesn't support this feature in
its emulation of QEMU.

Signed-off-by: Simon Glass <sjg@chromium.org>

cmd/qfw.c

@@ -219,6 +219,21 @@ static int do_arch(struct cmd_tbl *cmdtp, int flag, int argc,
 	return 0;
 }
 
+static int do_read(struct cmd_tbl *cmdtp, int flag, int argc,
+		   char * const argv[])
+{
+	int ret;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	ret = qfw_load_file(qfw_dev, argv[1], hextoul(argv[0], NULL));
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	return 0;
+}
+
 static struct cmd_tbl fwcfg_commands[] = {
 	U_BOOT_CMD_MKENT(list, 0, 1, qemu_fwcfg_do_list, "", ""),
 	U_BOOT_CMD_MKENT(cpus, 0, 1, qemu_fwcfg_do_cpus, "", ""),
@@ -226,6 +241,7 @@ static struct cmd_tbl fwcfg_commands[] = {
 	U_BOOT_CMD_MKENT(dump, 0, 1, do_dump, "", ""),
 	U_BOOT_CMD_MKENT(table, 0, 1, do_table, "", ""),
 	U_BOOT_CMD_MKENT(arch, 0, 1, do_arch, "", ""),
+	U_BOOT_CMD_MKENT(read, 2, 1, do_read, "", ""),
 };
 
 static int do_qemu_fw(struct cmd_tbl *cmdtp, int flag, int argc,
@@ -261,4 +277,5 @@ U_BOOT_CMD(
 	"    - cpus                             : print online cpu number\n"
 	"    - load <kernel addr> <initrd addr> : load kernel and initrd (if any), and setup for zboot\n"
 	"    - table                            : show /etc/table-loader\n"
-	"    - arch                             : show arch-specific data");
+	"    - arch                             : show arch-specific data\n"
+	"    - read <addr> <filename>           : read a flle into memory");

doc/usage/cmd/qfw.rst

@@ -17,6 +17,7 @@ Synopsis
     qfw load [kernel_addr [initrd_addr]]
     qfw table
     qfw arch
+    qfw read <addr> <filename>
 
 Description
 -----------
@@ -37,6 +38,8 @@ must be updated to take account of the address to which the tables are copied.
 
 The *qfw arch* command shows some items marked as 'arch local' in QEMU.
 
+The *qfw read* command allowing a QEMU file to be read into memory.
+
 kernel_addr
     address to which the file specified by the -kernel parameter of QEMU shall
     be loaded. Defaults to environment variable *loadaddr* and further to
@@ -47,6 +50,12 @@ initrd_addr
     be loaded. Defaults to environment variable *ramdiskaddr* and further to
     the value of *CFG_RAMDISK_ADDR*.
 
+addr
+    address to which `filename` is read into memory
+
+filename
+    filename of file to read into memory (as shown by *qfw list*)
+
 Examples
 --------
 
@@ -164,6 +173,31 @@ This shows the *qfw table* command on an x86 target:
     irq0 overr  = 0x00000001
     hpet        = 0x00000000
 
+This shows reading a named qfw file into memory then dumping it, using the
+provided size information:
+
+::
+
+    => qfw list
+        Addr     Size Sel Name
+    -------- -------- --- ------------
+           0        0  20 bios-geometry
+           0        0  21 bootorder
+    1ec3f000       14  22 etc/acpi/rsdp
+    1ec3f040    20000  23 etc/acpi/tables
+           0        4  24 etc/boot-fail-wait
+           0       28  25 etc/e820
+           0       18  26 etc/smbios/smbios-anchor
+           0      151  27 etc/smbios/smbios-tables
+           0        6  28 etc/system-states
+           0     1000  29 etc/table-loader
+           0        0  2a etc/tpm/log
+           0     2400  2b genroms/kvmvapic.bin
+    => qfw read 1000 etc/acpi/rsdp
+    => md.b 1000 14
+    00001000: 52 53 44 20 50 54 52 20 00 42 4f 43 48 53 20 00  RSD PTR .BOCHS .
+    00001010: 40 1c 00 00                                      @...
+
 
 Configuration
 -------------

test/cmd/qfw.c

@@ -98,3 +98,18 @@ static int cmd_test_qfw_arch(struct unit_test_state *uts)
 	return 0;
 }
 CMD_TEST(cmd_test_qfw_arch, UTF_CONSOLE);
+
+/* Test 'qfw read' command */
+static int cmd_test_qfw_read(struct unit_test_state *uts)
+{
+	char *ptr = map_sysmem(0x1000, 0x100);
+
+	if (IS_ENABLED(CONFIG_SANDBOX))
+		return -EAGAIN;
+
+	ut_assertok(run_command("qfw read 1000 etc/acpi/rsdp", 0));
+	ut_asserteq_strn("RSD PTR ", ptr);
+
+	return 0;
+}
+CMD_TEST(cmd_test_qfw_read, UTF_CONSOLE);