armv8: semihosting: add a command to load semihosted images
Instead of sprinkling custom code and calls over the Vexpress64
boardfile, create a command that loads images using semihosting
just like we would load from flash memory of over the network,
using a special command:
smhload <image> <address>
This will make it possible to remove some custom calls and
code and make the boot easier.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index d3f724b..edacb11 100644
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -13,6 +13,7 @@
* for them.
*/
#include <common.h>
+#include <command.h>
#include <asm/semihosting.h>
#define SYSOPEN 0x01
@@ -234,3 +235,72 @@
/* Return the file length (or -1 error indication) */
return len;
}
+
+static int smh_load_file(const char * const name, ulong load_addr,
+ ulong *end_addr)
+{
+ long fd;
+ long len;
+ long ret;
+
+ fd = smh_open(name, "rb");
+ if (fd == -1)
+ return -1;
+
+ len = smh_len_fd(fd);
+ if (len < 0) {
+ smh_close(fd);
+ return -1;
+ }
+
+ ret = smh_read(fd, (void *)load_addr, len);
+ smh_close(fd);
+
+ if (ret == 0) {
+ *end_addr = load_addr + len - 1;
+ printf("loaded file %s from %08lX to %08lX, %08lX bytes\n",
+ name,
+ load_addr,
+ *end_addr,
+ len);
+ } else {
+ printf("read failed\n");
+ return 0;
+ }
+
+ return 0;
+}
+
+static int do_smhload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+ if (argc == 3 || argc == 4) {
+ ulong load_addr;
+ ulong end_addr = 0;
+ ulong ret;
+ char end_str[64];
+
+ load_addr = simple_strtoul(argv[2], NULL, 16);
+ if (!load_addr)
+ return -1;
+
+ ret = smh_load_file(argv[1], load_addr, &end_addr);
+ if (ret < 0)
+ return 1;
+
+ /* Optionally save returned end to the environment */
+ if (argc == 4) {
+ sprintf(end_str, "0x%08lx", end_addr);
+ setenv(argv[3], end_str);
+ }
+ } else {
+ return CMD_RET_USAGE;
+ }
+ return 0;
+}
+
+U_BOOT_CMD(smhload, 4, 0, do_smhload, "load a file using semihosting",
+ "<file> 0x<address> [end var]\n"
+ " - load a semihosted file to the address specified\n"
+ " if the optional [end var] is specified, the end\n"
+ " address of the file will be stored in this environment\n"
+ " variable.\n");
diff --git a/doc/README.semihosting b/doc/README.semihosting
index 7248560..c016a4f 100644
--- a/doc/README.semihosting
+++ b/doc/README.semihosting
@@ -30,25 +30,10 @@
absence of CONFIG_BASE_FVP. This change is tested and works on both the
Foundation and Base fastmodel simulators.
-The level of semihosting support is minimal, restricted to just what it
-takes to load images to memory. If more semihosting functionality is
-required, such as file seek, outputting strings, reading characters, etc,
-then it can be easily added later.
+The semihosting code adds a command:
-We require that the board include file define these env variables:
-- kernel_name e.g. "uImage"
-- kernel_addr_r e.g. "0x80000000"
-- initrd_name e.g. "ramdisk.img"
-- initrd_addr_r e.g. "0x88000000"
-- fdt_name e.g. "devtree.dtb"
-- fdt_addr_r e.g. "0x83000000"
+ smhload <image> <address> [env var]
-Optionally, "fdt_high" and "initrd_high" can be specified as per
-their rules for allowing or preventing copying of these images.
-
-For the "fdt chosen" startup macro, this code will then define:
-- initrd_end (based on retrieving initrd_addr_r plus actual initrd_size)
-
-We will then load the kernel, initrd, and fdt into the specified
-locations in memory in a similar way that the ATF fastmodel code
-uses semihosting calls to load other boot stages and u-boot itself.
+That will load an image from the host filesystem into RAM at the specified
+address and optionally store the load end address in the specified
+environment variable.