1 files changed, 174 insertions, 0 deletions

diff --git a/lib/libsetjmp/arm/setjmp.S b/lib/libsetjmp/arm/setjmp.S
new file mode 100644
index 0000000000..ee5ebd9169
--- /dev/null
+++ b/lib/libsetjmp/arm/setjmp.S
@@ -0,0 +1,174 @@
+/* This is a simple version of setjmp and longjmp.
+
+   Nick Clifton, Cygnus Solutions, 13 June 1997.  */
+
+/* ANSI concatenation macros.  */
+#define CONCAT(a, b)  CONCAT2(a, b)
+#define CONCAT2(a, b) a##b
+
+#ifndef __USER_LABEL_PREFIX__
+#error  __USER_LABEL_PREFIX__ not defined
+#endif
+
+#define SYM(x) CONCAT (__USER_LABEL_PREFIX__, x)
+
+#ifdef __ELF__
+#define TYPE(x) .type SYM(x),function
+#define SIZE(x) .size SYM(x), . - SYM(x)
+#else
+#define TYPE(x)
+#define SIZE(x)
+#endif
+
+/* Arm/Thumb interworking support:
+
+   The interworking scheme expects functions to use a BX instruction
+   to return control to their parent.  Since we need this code to work
+   in both interworked and non-interworked environments as well as with
+   older processors which do not have the BX instruction we do the 
+   following:
+    Test the return address.
+    If the bottom bit is clear perform an "old style" function exit.
+    (We know that we are in ARM mode and returning to an ARM mode caller).
+    Otherwise use the BX instruction to perform the function exit.
+
+   We know that we will never attempt to perform the BX instruction on 
+   an older processor, because that kind of processor will never be 
+   interworked, and a return address with the bottom bit set will never 
+   be generated.
+
+   In addition, we do not actually assemble the BX instruction as this would
+   require us to tell the assembler that the processor is an ARM7TDMI and
+   it would store this information in the binary.  We want this binary to be
+   able to be linked with binaries compiled for older processors however, so
+   we do not want such information stored there.  
+
+   If we are running using the APCS-26 convention however, then we never
+   test the bottom bit, because this is part of the processor status.  
+   Instead we just do a normal return, since we know that we cannot be 
+   returning to a Thumb caller - the Thumb does not support APCS-26.
+    
+   Function entry is much simpler.  If we are compiling for the Thumb we 
+   just switch into ARM mode and then drop through into the rest of the
+   function.  The function exit code will take care of the restore to
+   Thumb mode.
+   
+   For Thumb-2 do everything in Thumb mode.  */
+
+#ifdef __APCS_26__
+#define RET movs        pc, lr
+#elif defined(__thumb2__)
+#define RET bx lr
+#elif !defined(ROCKBOX_SUPPORTS_AN_ARMV4_NON_T_CPU)
+#define RET bx lr   /* BX exists on v4T, v5 and more recent architectures */
+#else
+#define RET tst     lr, #1; \
+            moveq       pc, lr ; \
+.word           0xe12fff1e  /* bx lr */
+#endif
+
+#ifdef __thumb2__
+.macro COND where when 
+    i\where \when
+.endm
+#else
+.macro COND where when 
+.endm
+#endif
+
+#if defined(__thumb2__)
+.syntax unified
+.macro MODE
+    .thumb
+    .thumb_func
+.endm
+.macro PROLOGUE name
+.endm
+
+#elif defined(__thumb__)
+#define MODE        .thumb_func
+.macro PROLOGUE name
+    .code 16
+    bx  pc
+    nop 
+    .code 32
+SYM (.arm_start_of.\name):
+.endm
+#else /* Arm */
+#define MODE        .code 32
+.macro PROLOGUE name
+.endm
+#endif
+    
+.macro FUNC_START name
+    .text
+    .align 2
+    MODE
+    .globl SYM (\name)
+    TYPE (\name)
+SYM (\name):
+    PROLOGUE \name
+.endm
+
+.macro FUNC_END name
+    RET
+    SIZE (\name)
+.endm
+    
+/* --------------------------------------------------------------------
+                 int setjmp (jmp_buf); 
+   -------------------------------------------------------------------- */
+    
+    FUNC_START setjmp
+
+    /* Save all the callee-preserved registers into the jump buffer.  */
+#ifdef __thumb2__
+    stmea       a1!, { v1-v7, fp, ip, lr }
+    str     sp, [a1],#+4
+#else
+    stmea       a1!, { v1-v7, fp, ip, sp, lr }
+#endif
+    
+#if 0   /* Simulator does not cope with FP instructions yet.  */
+#ifndef __SOFTFP__
+    /* Save the floating point registers.  */
+    sfmea       f4, 4, [a1]
+#endif
+#endif      
+    /* When setting up the jump buffer return 0.  */
+    mov     a1, #0
+
+    FUNC_END setjmp
+    
+/* --------------------------------------------------------------------
+        volatile void longjmp (jmp_buf, int);
+   -------------------------------------------------------------------- */
+    
+    FUNC_START longjmp
+
+    /* If we have stack extension code it ought to be handled here.  */
+    
+    /* Restore the registers, retrieving the state when setjmp() was called.  */
+#ifdef __thumb2__
+    ldmfd       a1!, { v1-v7, fp, ip, lr }
+    ldr     sp, [a1],#+4
+#else
+    ldmfd       a1!, { v1-v7, fp, ip, sp, lr }
+#endif
+    
+#if 0   /* Simulator does not cope with FP instructions yet.  */
+#ifndef __SOFTFP__
+    /* Restore floating point registers as well.  */
+    lfmfd       f4, 4, [a1]
+#endif
+#endif  
+    /* Put the return value into the integer result register.
+       But if it is zero then return 1 instead.  */ 
+    movs        a1, a2
+#ifdef __thumb2__
+    it      eq
+#endif
+    moveq       a1, #1
+
+    FUNC_END longjmp
+