From a0b0a4a01820661724ee08f54fbba7a51b190c96 Mon Sep 17 00:00:00 2001 From: Alexander Fedotov Date: Thu, 11 Apr 2019 15:28:05 +0300 Subject: Align comments and spaces in libgloss/arm/crt0.S and newlib/libc/sys/arm/crt0.S to ease further code alignment. --- libgloss/arm/crt0.S | 135 ++++++++++++++++++++++++++-------------------------- 1 file changed, 68 insertions(+), 67 deletions(-) (limited to 'libgloss') diff --git a/libgloss/arm/crt0.S b/libgloss/arm/crt0.S index c708f63..1deb73a 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) -- cgit v1.1