[PATCH 1/2] Align comments and spaces in libgloss/arm/crt0.S and newlib/libc/sys/arm/crt0.S to ease further code alignment.

Alexander Fedotov alfedotov@gmail.com
Thu Jul 18 13:50:00 GMT 2019


Hi Richard

Could you please apply it for me. I have no write permissions.

Best regards,
Alex

On Thu, Jul 18, 2019 at 12:47 PM Richard Earnshaw (lists)
<Richard.Earnshaw@arm.com> wrote:
>
> OK.
>
> (sorry for the delay replying).
>
> R.
>
> On 12/04/2019 14:30, alfedotov@gmail.com wrote:
> > From: Alexander Fedotov <alfedotov@gmail.com>
> >
> > ---
> >   libgloss/arm/crt0.S        | 135 +++++++++++++++++++------------------
> >   newlib/libc/sys/arm/crt0.S |  18 ++---
> >   2 files changed, 78 insertions(+), 75 deletions(-)
> >
> > diff --git a/libgloss/arm/crt0.S b/libgloss/arm/crt0.S
> > index c708f63d8..1deb73aa5 100644
> > --- a/libgloss/arm/crt0.S
> > +++ b/libgloss/arm/crt0.S
> > @@ -68,8 +68,10 @@
> >   #endif
> >   .endm
> >
> > +/*******************************************************************************
> > +* Main library startup code.
> > +*******************************************************************************/
> >       .align  0
> > -
> >       FUNC_START      _mainCRTStartup
> >       FUNC_START      _start
> >   #if defined(__ELF__) && !defined(__USING_SJLJ_EXCEPTIONS__)
> > @@ -90,14 +92,14 @@
> >   #endif
> >   #endif
> >
> > -/* Start by setting up a stack */
> > +/* Start by setting up a stack.  */
> >   #ifdef ARM_RDP_MONITOR
> > -     /*  Issue Demon SWI to read stack info */
> > -     swi     SWI_GetEnv      /*  Returns command line in r0 */
> > -     mov     sp,r1           /*  and the highest memory address in r1 */
> > +     /*  Issue Demon SWI to read stack info.  */
> > +     swi     SWI_GetEnv      /*  Returns command line in r0.  */
> > +     mov     sp,r1           /*  and the highest memory address in r1.  */
> >
> > -     /*  stack limit is at end of data */
> > -     /*  allow slop for stack overflow handling and small frames */
> > +     /*  Stack limit is at end of data.  */
> > +     /*  Allow slop for stack overflow handling and small frames.  */
> >   #ifdef THUMB1_ONLY
> >       ldr     r0, .LC2
> >       adds    r0, #128
> > @@ -109,19 +111,19 @@
> >   #endif
> >   #else
> >   #ifdef ARM_RDI_MONITOR
> > -     /*  Issue Angel SWI to read stack info */
> > +     /*  Issue Angel SWI to read stack info.  */
> >       movs    r0, #AngelSWI_Reason_HeapInfo
> > -     adr     r1, .LC0        /*  point at ptr to 4 words to receive data */
> > +     adr     r1, .LC0        /*  Point at ptr to 4 words to receive data.  */
> >   #ifdef THUMB_VXM
> >       bkpt    AngelSWI
> >   #elif defined(__thumb2__)
> > -     /*  We are in thumb mode for startup on armv7 architectures. */
> > +     /*  We are in thumb mode for startup on armv7 architectures.  */
> >       AngelSWIAsm (AngelSWI)
> >   #else
> > -     /*  We are always in ARM mode for startup on pre armv7 archs. */
> > +     /*  We are always in ARM mode for startup on pre armv7 archs.  */
> >       AngelSWIAsm (AngelSWI_ARM)
> >   #endif
> > -     ldr     r0, .LC0        /*  point at values read */
> > +     ldr     r0, .LC0        /*  Point at values read.  */
> >
> >       /* Set __heap_limit.  */
> >       ldr     r1, [r0, #4]
> > @@ -148,14 +150,15 @@
> >             to skip setting sp/sl to 0 here.
> >           - Considering M-profile processors, We might want to initialize
> >             sp by the first entry of vector table and return 0 to SYS_HEAPINFO
> > -           semihosting call, which will be skipped here. */
> > +           semihosting call, which will be skipped here.  */
> >       cmp     r1, #0
> >       beq     .LC26
> >       mov     sp, r1
> >   .LC26:
> >       cmp     r2, #0
> >       beq     .LC27
> > -     /*  allow slop for stack overflow handling and small frames */
> > +
> > +     /*  Allow slop for stack overflow handling and small frames.  */
> >   #ifdef THUMB1_ONLY
> >       adds    r2, #128
> >       adds    r2, #128
> > @@ -163,9 +166,10 @@
> >   #else
> >       add     sl, r2, #256
> >   #endif
> > +
> >   .LC27:
> >   #else
> > -     /*  Set up the stack pointer to a fixed value */
> > +     /*  Set up the stack pointer to a fixed value.  */
> >       /*  Changes by toralf:
> >           - Allow linker script to provide stack via __stack symbol - see
> >             defintion of .Lstack
> > @@ -175,7 +179,7 @@
> >             Loosely based on init.s from ARM/Motorola example code.
> >                 Note: Mode switch via CPSR is not allowed once in non-privileged
> >                   mode, so we take care not to enter "User" to set up its sp,
> > -                 and also skip most operations if already in that mode. */
> > +                 and also skip most operations if already in that mode.  */
> >
> >       ldr     r3, .Lstack
> >       cmp     r3, #0
> > @@ -192,42 +196,42 @@
> >       /* Note: This 'mov' is essential when starting in User, and ensures we
> >                always get *some* sp value for the initial mode, even if we
> >                have somehow missed it below (in which case it gets the same
> > -              value as FIQ - not ideal, but better than nothing.) */
> > +              value as FIQ - not ideal, but better than nothing).  */
> >       mov     sp, r3
> >   #ifdef PREFER_THUMB
> >       /* XXX Fill in stack assignments for interrupt modes.  */
> >   #else
> >       mrs     r2, CPSR
> > -     tst     r2, #0x0F       /* Test mode bits - in User of all are 0 */
> > -     beq     .LC23           /* "eq" means r2 AND #0x0F is 0 */
> > -     msr     CPSR_c, #0xD1   /* FIRQ mode, interrupts disabled */
> > +     tst     r2, #0x0F       /* Test mode bits - in User of all are 0.  */
> > +     beq     .LC23           /* "eq" means r2 AND #0x0F is 0.  */
> > +     msr     CPSR_c, #0xD1   /* FIRQ mode, interrupts disabled.  */
> >       mov     sp, r3
> > -     sub     sl, sp, #0x1000 /* This mode also has its own sl (see below) */
> > +     sub     sl, sp, #0x1000 /* This mode also has its own sl (see below).  */
> >
> >       mov     r3, sl
> > -     msr     CPSR_c, #0xD7   /* Abort mode, interrupts disabled */
> > +     msr     CPSR_c, #0xD7   /* Abort mode, interrupts disabled.  */
> >       mov     sp, r3
> >       sub     r3, r3, #0x1000
> >
> > -     msr     CPSR_c, #0xDB   /* Undefined mode, interrupts disabled */
> > +     msr     CPSR_c, #0xDB   /* Undefined mode, interrupts disabled.  */
> >       mov     sp, r3
> >       sub     r3, r3, #0x1000
> >
> > -     msr     CPSR_c, #0xD2   /* IRQ mode, interrupts disabled */
> > +     msr     CPSR_c, #0xD2   /* IRQ mode, interrupts disabled.  */
> >       mov     sp, r3
> >       sub     r3, r3, #0x2000
> >
> > -     msr     CPSR_c, #0xD3   /* Supervisory mode, interrupts disabled */
> > +     msr     CPSR_c, #0xD3   /* Supervisory mode, interrupts disabled.  */
> >
> >       mov     sp, r3
> > -     sub     r3, r3, #0x8000 /* Min size 32k */
> > -     bic     r3, r3, #0x00FF /* Align with current 64k block */
> > +     sub     r3, r3, #0x8000 /* Min size 32k.  */
> > +     bic     r3, r3, #0x00FF /* Align with current 64k block.  */
> >       bic     r3, r3, #0xFF00
> >
> >       str     r3, [r3, #-4]   /* Move value into user mode sp without */
> > -     ldmdb   r3, {sp}^       /* changing modes, via '^' form of ldm */
> > +     ldmdb   r3, {sp}^       /* changing modes, via '^' form of ldm.  */
> >       orr     r2, r2, #0xC0   /* Back to original mode, presumably SVC, */
> > -     msr     CPSR_c, r2      /* with FIQ/IRQ disable bits forced to 1 */
> > +     msr     CPSR_c, r2      /* with FIQ/IRQ disable bits forced to 1.  */
> >   #endif
> >   .LC23:
> >       /* Setup a default stack-limit in-case the code has been
> > @@ -243,24 +247,24 @@
> >       subs    r2, r3, r2
> >       mov     sl, r2
> >   #else
> > -     sub     sl, r3, #64 << 10       /* Still assumes 256bytes below sl */
> > +     sub     sl, r3, #64 << 10       /* Still assumes 256bytes below sl.  */
> >   #endif
> >   #endif
> >   #endif
> >       /* Zero the memory in the .bss section.  */
> > -     movs    a2, #0                  /* Second arg: fill value */
> > -     mov     fp, a2                  /* Null frame pointer */
> > -     mov     r7, a2                  /* Null frame pointer for Thumb */
> > +     movs    a2, #0                  /* Second arg: fill value.  */
> > +     mov     fp, a2                  /* Null frame pointer.  */
> > +     mov     r7, a2                  /* Null frame pointer for Thumb.  */
> >
> > -     ldr     a1, .LC1                /* First arg: start of memory block */
> > +     ldr     a1, .LC1                /* First arg: start of memory block.  */
> >       ldr     a3, .LC2
> > -     subs    a3, a3, a1              /* Third arg: length of block */
> > +     subs    a3, a3, a1              /* Third arg: length of block.  */
> >
> >
> >   #if __thumb__ && !defined(PREFER_THUMB)
> > -     /* Enter Thumb mode.... */
> > -     add     a4, pc, #1      /* Get the address of the Thumb block */
> > -     bx      a4              /* Go there and start Thumb decoding  */
> > +     /* Enter Thumb mode...  */
> > +     add     a4, pc, #1      /* Get the address of the Thumb block.  */
> > +     bx      a4              /* Go there and start Thumb decoding.  */
> >
> >       .code 16
> >       .global __change_mode
> > @@ -271,9 +275,8 @@ __change_mode:
> >       bl      FUNCTION (memset)
> >   #if !defined (ARM_RDP_MONITOR) && !defined (ARM_RDI_MONITOR)
> >   /* Changes by toralf: Taken from libgloss/m68k/crt0.S
> > - * initialize target specific stuff. Only execute these
> > - * functions it they exist.
> > - */
> > +   initialize target specific stuff. Only execute these
> > +   functions it they exist.  */
> >       ldr     r3, .Lhwinit
> >       cmp     r3, #0
> >       beq     .LC24
> > @@ -285,24 +288,24 @@ __change_mode:
> >       indirect_call r3
> >
> >   .LC25:
> > -     movs    r0, #0          /*  no arguments  */
> > -     movs    r1, #0          /*  no argv either */
> > +     movs    r0, #0          /* No arguments.  */
> > +     movs    r1, #0          /* No argv either.  */
> >   #else
> > -     /* Need to set up standard file handles */
> > +     /* Need to set up standard file handles.  */
> >       bl      FUNCTION (initialise_monitor_handles)
> >
> >   #ifdef ARM_RDP_MONITOR
> > -     swi     SWI_GetEnv      /*  sets r0 to point to the command line */
> > +     swi     SWI_GetEnv      /* Sets r0 to point to the command line.  */
> >       movs    r1, r0
> >   #else
> >       movs    r0, #AngelSWI_Reason_GetCmdLine
> > -     ldr     r1, .LC30       /*  Space for command line */
> > +     ldr     r1, .LC30       /* Space for command line.  */
> >       AngelSWIAsm (AngelSWI)
> >       ldr     r1, .LC30
> >       ldr     r1, [r1]
> >   #endif
> > -     /*  Parse string at r1 */
> > -     movs    r0, #0          /*  count of arguments so far */
> > +     /*  Parse string at r1.  */
> > +     movs    r0, #0          /* Count of arguments so far.  */
> >       /* Push a NULL argument onto the end of the list.  */
> >   #ifdef __thumb__
> >       push    {r0}
> > @@ -310,7 +313,7 @@ __change_mode:
> >       stmfd   sp!, {r0}
> >   #endif
> >   .LC10:
> > -/*  Skip leading blanks */
> > +/*  Skip leading blanks.  */
> >   #ifdef __thumb__
> >       ldrb    r3, [r1]
> >       adds    r1, #1
> > @@ -322,7 +325,7 @@ __change_mode:
> >       cmp     r3, #' '
> >       beq     .LC10
> >
> > -/*  See whether we are scanning a string */
> > +/* See whether we are scanning a string.  */
> >       cmp     r3, #'"'
> >   #ifdef __thumb__
> >       beq     .LC20
> > @@ -333,17 +336,17 @@ __change_mode:
> >       b       .LC22
> >
> >   .LC21:
> > -     movs    r2, #' '        /*  terminator type */
> > -     subs    r1, r1, #1      /*  adjust back to point at start char */
> > +     movs    r2, #' '        /* Terminator type.  */
> > +     subs    r1, r1, #1      /* Adjust back to point at start char.  */
> >   .LC22:
> >   #else
> >       cmpne   r3, #'\''
> >       moveq   r2, r3
> > -     movne   r2, #' '        /*  terminator type */
> > -     subne   r1, r1, #1      /*  adjust back to point at start char */
> > +     movne   r2, #' '        /* Terminator type.  */
> > +     subne   r1, r1, #1      /* Adjust back to point at start char.  */
> >   #endif
> >
> > -/*  Stack a pointer to the current argument */
> > +/*  Stack a pointer to the current argument.  */
> >   #ifdef __thumb__
> >       push    {r1}
> >   #else
> > @@ -359,16 +362,16 @@ __change_mode:
> >   #endif
> >       cmp     r3, #0
> >       beq     .LC12
> > -     cmp     r2, r3          /*  reached terminator? */
> > +     cmp     r2, r3          /* Reached terminator ?  */
> >       bne     .LC11
> >       movs    r2, #0
> >       subs    r3, r1, #1
> > -     strb    r2, [r3]        /*  terminate the arg string */
> > +     strb    r2, [r3]        /* Terminate the arg string.  */
> >       b       .LC10
> >
> >   .LC12:
> > -     mov     r1, sp          /*  point at stacked arg pointers */
> > -     /* We've now got the stacked args in order reverse the */
> > +     mov     r1, sp          /* Point at stacked arg pointers.  */
> > +     /* We've now got the stacked args in order, reverse them.  */
> >   #ifdef __thumb__
> >       movs    r2, r0
> >       lsls    r2, #2
> > @@ -390,10 +393,10 @@ __change_mode:
> >       bics    r4, r5
> >       mov     sp, r4
> >   #else
> > -     add     r2, sp, r0, LSL #2      /* End of args */
> > -     mov     r3, sp                  /* Start of args */
> > +     add     r2, sp, r0, LSL #2      /* End of args.  */
> > +     mov     r3, sp                  /* Start of args.  */
> >   .LC13:      cmp     r2, r3
> > -     ldrhi   r4,[r2, #-4]            /* Reverse ends of list */
> > +     ldrhi   r4,[r2, #-4]            /* Reverse ends of list.  */
> >       ldrhi   r5, [r3]
> >       strhi   r5, [r2, #-4]!
> >       strhi   r4, [r3], #4
> > @@ -431,7 +434,6 @@ __change_mode:
> >
> >   #if __thumb__ && !defined(PREFER_THUMB)
> >       /* Come out of Thumb mode.  This code should be redundant.  */
> > -
> >       mov     a4, pc
> >       bx      a4
> >
> > @@ -447,7 +449,6 @@ change_back:
> >
> >       /* For Thumb, constants must be after the code since only
> >          positive offsets are supported for PC relative addresses.  */
> > -
> >       .align 0
> >   .LC0:
> >   #ifdef ARM_RDI_MONITOR
> > @@ -457,13 +458,13 @@ change_back:
> >       /* Changes by toralf: Provide alternative "stack" variable whose value
> >          may be defined externally; .Lstack will be used instead of .LC0 if
> >          it points to a non-0 value. Also set up references to "hooks" that
> > -           may be used by the application to provide additional init code. */
> > -
> > +           may be used by the application to provide additional init code.  */
> >   #ifdef __pe__
> >       .word   0x800000
> >   #else
> >       .word   0x80000                 /* Top of RAM on the PIE board.  */
> >   #endif
> > +
> >   .Lstack:
> >       .word   __stack
> >   .Lhwinit:
> > @@ -476,7 +477,7 @@ change_back:
> >          runtime (meaning "ignore setting") for the variables, when the user
> >          does not provide the symbols. (The linker uses a weak symbol if,
> >          and only if, a normal version of the same symbol isn't provided
> > -        e.g. by a linker script or another object file.) */
> > +        e.g. by a linker script or another object file.)  */
> >
> >       .weak __stack
> >       .weak FUNCTION (hardware_init_hook)
> > diff --git a/newlib/libc/sys/arm/crt0.S b/newlib/libc/sys/arm/crt0.S
> > index 8c9f7be38..7a6b40d9a 100644
> > --- a/newlib/libc/sys/arm/crt0.S
> > +++ b/newlib/libc/sys/arm/crt0.S
> > @@ -50,13 +50,13 @@
> >       .global \name
> >       .thumb_func
> >   \name:
> > -.endm
> > +.endm
> >   #else
> >       .code 32
> >   .macro FUNC_START name
> > -     .global \name
> > +     .global \name
> >   \name:
> > -.endm
> > +.endm
> >   #endif
> >
> >   .macro indirect_call reg
> > @@ -68,8 +68,10 @@
> >   #endif
> >   .endm
> >
> > +/*******************************************************************************
> > +* Main library startup code.
> > +*******************************************************************************/
> >       .align  0
> > -
> >       FUNC_START      _mainCRTStartup
> >       FUNC_START      _start
> >   #if defined(__ELF__) && !defined(__USING_SJLJ_EXCEPTIONS__)
> > @@ -399,7 +401,7 @@ __change_mode:
> >       bl      FUNCTION (_init)
> >       movs    r0, r4
> >       movs    r1, r5
> > -#endif
> > +#endif
> >       bl      FUNCTION (main)
> >
> >       bl      FUNCTION (exit)         /* Should not return.  */
> > @@ -420,7 +422,7 @@ change_back:
> >   #endif
> >
> >       /* For Thumb, constants must be after the code since only
> > -        positive offsets are supported for PC relative addresses.  */
> > +        positive offsets are supported for PC relative addresses.  */
> >       .align 0
> >   .LC0:
> >   #ifdef ARM_RDI_MONITOR
> > @@ -430,7 +432,7 @@ change_back:
> >       /* Changes by toralf: Provide alternative "stack" variable whose value
> >          may be defined externally; .Lstack will be used instead of .LC0 if
> >          it points to a non-0 value. Also set up references to "hooks" that
> > -           may be used by the application to provide additional init code.  */
> > +           may be used by the application to provide additional init code.  */
> >   #ifdef __pe__
> >       .word   0x800000
> >   #else
> > @@ -449,7 +451,7 @@ change_back:
> >          runtime (meaning "ignore setting") for the variables, when the user
> >          does not provide the symbols. (The linker uses a weak symbol if,
> >          and only if, a normal version of the same symbol isn't provided
> > -        e.g. by a linker script or another object file).  */
> > +        e.g. by a linker script or another object file.)  */
> >
> >       .weak __stack
> >       .weak FUNCTION (hardware_init_hook)
> >



More information about the Newlib mailing list