arm-semi: Provide access to CLI arguments passed through the "-append" option

This patch basically adapts the new semi-hosting command-line support
-- introduced by Wolfgang Schildbach in the commit 2e8785ac -- for use
in system-mode.

Note that the "arm_cmdline_len" and "host_cmdline_len" variables were
renamed respectively "input_size" and "output_size" because:

    * in C, the term "length" is generally used to count the number of
      character in a string, not to count the number of bytes in a
      buffer (as it is the case here).

    * in QEMU, the term "host" is used to name variables that are in
      the host address space, not to name variables in the target
      address space (as it is the case here).

    * in the case of this system-call, the terms "input" and "output"
      fit the semantic of the official ARM semi-hosting specification
      quite well.

I know renaming can be considered harmful but I do think in this case
the semantic really matters to keep this code more understandable.

Signed-off-by: Cédric VINCENT <cedric.vincent@st.com>
Reviewed-by: Christophe Lyon <christophe.lyon@st.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Paul Brook <paul@codesourcery.com>
Cc: Wolfgang Schildbach <wschi@dolby.com>
Cc: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Cédric VINCENT 2011-06-29 12:49:41 +02:00 committed by Riku Voipio
parent 9312805d33
commit 1c1b40c162

View file

@ -34,6 +34,7 @@
#else
#include "qemu-common.h"
#include "gdbstub.h"
#include "hw/arm-misc.h"
#endif
#define SYS_OPEN 0x01
@ -369,68 +370,88 @@ uint32_t do_arm_semihosting(CPUState *env)
return syscall_err;
#endif
case SYS_GET_CMDLINE:
#ifdef CONFIG_USER_ONLY
/* Build a commandline from the original argv. */
{
char *arm_cmdline_buffer;
const char *host_cmdline_buffer;
/* Build a command-line from the original argv.
*
* The inputs are:
* * ARG(0), pointer to a buffer of at least the size
* specified in ARG(1).
* * ARG(1), size of the buffer pointed to by ARG(0) in
* bytes.
*
* The outputs are:
* * ARG(0), pointer to null-terminated string of the
* command line.
* * ARG(1), length of the string pointed to by ARG(0).
*/
char *output_buffer;
size_t input_size = ARG(1);
size_t output_size;
int status = 0;
/* Compute the size of the output string. */
#if !defined(CONFIG_USER_ONLY)
output_size = strlen(ts->boot_info->kernel_filename)
+ 1 /* Separating space. */
+ strlen(ts->boot_info->kernel_cmdline)
+ 1; /* Terminating null byte. */
#else
unsigned int i;
unsigned int arm_cmdline_len = ARG(1);
unsigned int host_cmdline_len =
ts->info->arg_end-ts->info->arg_start;
if (!arm_cmdline_len || host_cmdline_len > arm_cmdline_len) {
return -1; /* not enough space to store command line */
}
if (!host_cmdline_len) {
output_size = ts->info->arg_end - ts->info->arg_start;
if (!output_size) {
/* We special-case the "empty command line" case (argc==0).
Just provide the terminating 0. */
arm_cmdline_buffer = lock_user(VERIFY_WRITE, ARG(0), 1, 0);
arm_cmdline_buffer[0] = 0;
unlock_user(arm_cmdline_buffer, ARG(0), 1);
/* Adjust the commandline length argument. */
SET_ARG(1, 0);
return 0;
output_size = 1;
}
/* lock the buffers on the ARM side */
arm_cmdline_buffer =
lock_user(VERIFY_WRITE, ARG(0), host_cmdline_len, 0);
host_cmdline_buffer =
lock_user(VERIFY_READ, ts->info->arg_start,
host_cmdline_len, 1);
if (arm_cmdline_buffer && host_cmdline_buffer)
{
/* the last argument is zero-terminated;
no need for additional termination */
memcpy(arm_cmdline_buffer, host_cmdline_buffer,
host_cmdline_len);
/* separate arguments by white spaces */
for (i = 0; i < host_cmdline_len-1; i++) {
if (arm_cmdline_buffer[i] == 0) {
arm_cmdline_buffer[i] = ' ';
}
}
/* Adjust the commandline length argument. */
SET_ARG(1, host_cmdline_len-1);
}
/* Unlock the buffers on the ARM side. */
unlock_user(arm_cmdline_buffer, ARG(0), host_cmdline_len);
unlock_user((void*)host_cmdline_buffer, ts->info->arg_start, 0);
/* Return success if we could return a commandline. */
return (arm_cmdline_buffer && host_cmdline_buffer) ? 0 : -1;
}
#else
return -1;
#endif
if (output_size > input_size) {
/* Not enough space to store command-line arguments. */
return -1;
}
/* Adjust the command-line length. */
SET_ARG(1, output_size - 1);
/* Lock the buffer on the ARM side. */
output_buffer = lock_user(VERIFY_WRITE, ARG(0), output_size, 0);
if (!output_buffer) {
return -1;
}
/* Copy the command-line arguments. */
#if !defined(CONFIG_USER_ONLY)
pstrcpy(output_buffer, output_size, ts->boot_info->kernel_filename);
pstrcat(output_buffer, output_size, " ");
pstrcat(output_buffer, output_size, ts->boot_info->kernel_cmdline);
#else
if (output_size == 1) {
/* Empty command-line. */
output_buffer[0] = '\0';
goto out;
}
if (copy_from_user(output_buffer, ts->info->arg_start,
output_size)) {
status = -1;
goto out;
}
/* Separate arguments by white spaces. */
for (i = 0; i < output_size - 1; i++) {
if (output_buffer[i] == 0) {
output_buffer[i] = ' ';
}
}
out:
#endif
/* Unlock the buffer on the ARM side. */
unlock_user(output_buffer, ARG(0), output_size);
return status;
}
case SYS_HEAPINFO:
{
uint32_t *ptr;