diff options
| author | Alexander Fedotov <alfedotov@gmail.com> | 2019-08-02 15:33:43 +0300 |
|---|---|---|
| committer | Richard Earnshaw <Richard.Earnshaw@arm.com> | 2019-08-05 15:00:53 +0300 |
| commit | 37e80fbb1c329ab39d154a78fa6d99f28d220dfe (patch) | |
| tree | 74fb9fbcc924b1ff634ca41b439edd56d59b2215 /newlib/libc/sys | |
| parent | 362b98b49af53496f07c36a8b946a3be584a370e (diff) | |
Align libgloss/arm and libc/sys/arm sources: Fix GetCmdLine semihosting directives
Applied changes from the commit 9b11672:
When simulating arm code, the target program startup code (crt0) uses
semihosting invocations to get the command line from the simulator. The
simulator returns the command line and its size into the area passed in
parameter. (ARM 32-bit specifications :
http://infocenter.arm.com/help/topic/com.arm.doc.dui0058d/DUI0058.pdf
chapter "5.4.19 SYS_GET_CMDLINE").
The memory area pointed by the semihosting register argument is located
in .text section (usually not writtable (RX)).
If we run this code on a simulator that respects this rights properties
(qemu user-mode for instance), the command line will not be written to
the .text program memory, in particular the length of the string. The
program runs with an empty command line. This problem hasn't been seen
earlier probably because qemu user-mode is not so much used, but this can
happen with another simulator that refuse to write in a read-only segment.
With this modification, the command line can be correctly passed to the
target program.
Changes:
- newlib/libc/sys/arm/crt0.S : Arguments passed to the
AngelSWI_Reason_GetCmdLine semihosting invocation are placed into .data
section instead of .text
Diffstat (limited to 'newlib/libc/sys')
| -rw-r--r-- | newlib/libc/sys/arm/crt0.S | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/newlib/libc/sys/arm/crt0.S b/newlib/libc/sys/arm/crt0.S index 9c262428d..40bbc3d69 100644 --- a/newlib/libc/sys/arm/crt0.S +++ b/newlib/libc/sys/arm/crt0.S @@ -393,13 +393,14 @@ __change_mode: movs r1, r0 #else movs r0, #AngelSWI_Reason_GetCmdLine - adr r1, .LC30 /* Space for command line. */ + ldr r1, .LC30 /* Space for command line. */ #ifdef THUMB_VXM bkpt AngelSWI #else AngelSWIAsm AngelSWI #endif ldr r1, .LC30 + ldr r1, [r1] #endif /* Parse string at r1. */ movs r0, #0 /* Count of arguments so far. */ @@ -586,8 +587,7 @@ change_back: #endif #ifdef ARM_RDI_MONITOR .LC30: - .word CommandLine - .word 255 + .word AngelSWIArgs .LC31: .word __end__ @@ -600,6 +600,9 @@ HeapLimit: .word 0 __stack_base__: .word 0 StackLimit: .word 0 CommandLine: .space 256,0 /* Maximum length of 255 chars handled. */ +AngelSWIArgs: + .word CommandLine + .word 255 #endif #ifdef __pe__ |