CCS/PROCESSOR-SDK-AM335X: Have BIOS heap use the maximum amount of memory available

Hi,

I don't think the sectionSpec loadAddress needs to be used.

Please see <XDCTools>/docs/docs/cdoc/xdc/cfg/Program.html, config Program.sectMap // module-wide:

Suppose for example that the platform defines a memory segment named "DDR2". The following configuration statement places everything from the ".text" section into the "DDR2" segment.
Program.sectMap[".text"] = new Program.SectionSpec();
Program.sectMap[".text"].loadSegment = "DDR2";

In this case the linker determines the location.

I've looped in a colleague to comment more if required.

Regards,
Frank

I have tried this already but this has 2 problems.

1) You still have to specify the heap size.

2) The bin file becomes huge (512MB, or the entire size of RAM) due to the lack of control that we have over the ordering of the sections from the cfg file.  

HI,

You're saying the size of the bin file depends on the size & location of the heap? If that's the case, then I suspect an issue with 0's being included in the image as initializes for the heap memory.

Regards,
Frank

Absolutely.  If the heap is placed in between two sections with code or data then objcopy will grow the bin file to accommodate it.

I don't think the bin file should increase because the heap increases since the heap is RAM. A bin file should only include initialized data.

I assume you're using the GCC compiler. Have you tried using Program.sectionsExclude? For example:

// Remove section to exclude 0's for heap initialization from ARM image.
// Must have corresponding NOLOAD specifier for this section in linker command file.
Program.sectionsExclude = "^\.myHeap";

Regards,
Frank

I tried removing the runAddress/loadAddress and adding the ".system.heap" section the Program.sectionsExclude but objcopy still creates a huge bin file (491MB).  

Here is the resulting linker.cmd file:

/*
 * This file was generated by linkcmd_bm_v7a.xdt from the gnu.target.arm  package.
 */

ENTRY(_c_int00)

__TI_STACK_SIZE = 0x1000;
__STACK_SIZE = __TI_STACK_SIZE;

__HEAP_SIZE = 0x0;

INPUT(
    "/home/clarkson/projects/er-301/bin/firmware/sysbios/package/cfg/release_pa8fg.oa8fg"
    "/home/clarkson/projects/er-301/bin/firmware/sysbios/package/cfg/release_pa8fg.src/sysbios/sysbios.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/gnu.targets.arm.rtsv7A.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/boot.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/syscalls.aa8fg"
)

MEMORY
{
    SRAM (RWX) : org = 0x402f0400, len = 0x1fbff
    DDR3 (RWX) : org = 0x80000000, len = 0x20000000
}

/*
 * In order to put the .bass, .text, .data, .heap or .stack into a
 * different memory section, change the corresponding REGION_ALIAS.
 */
REGION_ALIAS("REGION_BSS", DDR3);
REGION_ALIAS("REGION_TEXT", DDR3);
REGION_ALIAS("REGION_DATA", DDR3);
REGION_ALIAS("REGION_STACK", DDR3);
REGION_ALIAS("REGION_HEAP", DDR3);
REGION_ALIAS("REGION_ARM_EXTAB", DDR3);
REGION_ALIAS("REGION_ARM_EXIDX", DDR3);

/*
 * symbolic aliases for static instance objects
 */
xdc_runtime_Startup__EXECFXN__C = 1;
xdc_runtime_Startup__RESETFXN__C = 1;

/*
 * Linker command file contributions from all loaded packages:
 */

/* Content from ti.sysbios.family.arm (ti/sysbios/family/arm/linkcmd.xdt): */

/* Content from ti.sysbios.rts (ti/sysbios/rts/linkcmd.xdt): */

/* Content from ti.sysbios.family.arm.a8.intcps (ti/sysbios/family/arm/a8/intcps/linkcmd.xdt): */
ti_sysbios_family_arm_a8_intcps_Hwi_intc = 0x48200000;


SECTIONS {

        .c_int00 0x80000000 : {*(.c_int00)} 
    .vecs : {*(.vecs)}  AT> DDR3
    ti.sysbios.family.arm.a8.mmuTableSection (NOLOAD) : {*(ti.sysbios.family.arm.a8.mmuTableSection)}  AT> DDR3
    xdc.meta (COPY) : {KEEP(*(xdc.meta))}  AT> DDR3


    .c_int00 : {
        KEEP (*(.c_int00))
    } > REGION_TEXT

    .text : {
        CREATE_OBJECT_SYMBOLS
        KEEP (*(.resetVecs))
        KEEP (*(.text))
        *(.text.*)
        *(.gnu.linkonce.t*)
        *(.gnu.warning)
        *(.glue*)
        . = ALIGN(0x4);
        KEEP (*(.ctors))
        *(.gnu.linkonce.r.*)
        . = ALIGN(0x4);
        __init_array_start = .;
        KEEP(*(SORT(.init_array.*)))
        KEEP(*(.init_array))
        __init_array_end = .;
        *(.init)
        *(.fini*)
    } > REGION_TEXT

    .rodata : {
        *(.rodata)
        *(.rodata.*)
    } > REGION_TEXT

    .ARM.extab : {
        *(.ARM.extab*)
        *(.gnu.linkonce.armextab.*)
    } > REGION_ARM_EXTAB

    .ARM.exidx : {
        __exidx_start = .;
        *(.ARM.exidx*)
        *(.gnu.linkonce.armexidx.*)
        __exidx_end = .;
    } > REGION_ARM_EXIDX

    etext   = .;
    _etext  = .;
    __etext = .;

    .data : {
        __data_load__ = LOADADDR (.data);
        __data_start__ = .;
        *(.got.plt)
        *(.got)
        *(.shdata)
        KEEP (*(.data))
        KEEP (*(.data*))
        *(.gnu.linkonce.d.*)
        . = ALIGN (4);
        __data_end__ = .;
    } > REGION_DATA AT> REGION_TEXT

    /*
     * Place .heap section before .bss and .stack as the _sbrk
     * implementation in librdimon.a compares the (heap_end + incr)
     * to the current SP value to check if the heap has overlapped
     * with the stack. 
     *
     * If .heap is placed between .bss and .stack in a SYS/BIOS app,
     * when the task stack (allocated in .bss) is the current stack,
     * the heap check in _sbrk will fail and trigger an error even
     * though the heap might not have actually overlapped with the
     * system stack.
     */
    .heap : ALIGN(0x100) {
        __heap_start__ = .;
        end = __heap_start__;
        _end = end;
        __end = end;
        . += __HEAP_SIZE;
        __heap_end__ = .;
        __HeapLimit = __heap_end__;
    } > REGION_HEAP

    .bss : {
        __bss_start__ = .;
        *(.shbss)
        KEEP (*(.bss))
        *(.bss.*)
        *(.gnu.linkonce.b.*)
        *(COMMON)
        . = ALIGN (4);
        __bss_end__ = .;
    } > REGION_BSS

    .stack : ALIGN(0x0008) {
        __TI_STACK_BASE = .;
        __stack = .;
        . += __TI_STACK_SIZE;
    } > REGION_STACK

    .stab           0 : { *(.stab) }
    .stabstr        0 : { *(.stabstr) }
    .stab.excl      0 : { *(.stab.excl) }
    .stab.exclstr   0 : { *(.stab.exclstr) }
    .stab.index     0 : { *(.stab.index) }
    .stab.indexstr  0 : { *(.stab.indexstr) }
    .comment        0 : { *(.comment) }

    .debug          0 : { *(.debug) }
    .line           0 : { *(.line)  }
    .debug_srcinfo  0 : { *(.debug_srcinfo) }
    .debug_sfnames  0 : { *(.debug_sfnames) }
    .debug_aranges  0 : { *(.debug_aranges) }
    .debug_pubnames 0 : { *(.debug_pubnames) }
    .debug_info     0 : { *(.debug_info) }
    .debug_abbrev   0 : { *(.debug_abbrev) }
    .debug_line     0 : { *(.debug_line) }
    .debug_frame    0 : { *(.debug_frame) }
    .debug_str      0 : { *(.debug_str) }
    .debug_loc      0 : { *(.debug_loc) }
    .debug_macinfo  0 : { *(.debug_macinfo) }
    .debug_weaknames    0 : { *(.debug_weaknames) }
    .debug_funcnames    0 : { *(.debug_funcnames) }
    .debug_typenames    0 : { *(.debug_typenames) }
    .debug_varnames     0 : { *(.debug_varnames) }
    .debug_pubtypes     0 : { *(.debug_pubtypes) }
    .debug_ranges       0 : { *(.debug_ranges) }

}

/* function aliases */
xdc_runtime_System_asprintf_va__E = xdc_runtime_System_asprintf_va__F;
xdc_runtime_System_snprintf_va__E = xdc_runtime_System_snprintf_va__F;
xdc_runtime_System_printf_va__E = xdc_runtime_System_printf_va__F;
xdc_runtime_System_aprintf_va__E = xdc_runtime_System_aprintf_va__F;
xdc_runtime_System_sprintf_va__E = xdc_runtime_System_sprintf_va__F;

and here is the cfg file:

// Configuration shared by all builds of SYS/BIOS.

var Defaults = xdc.useModule('xdc.runtime.Defaults');
var Diags = xdc.useModule('xdc.runtime.Diags');
var Assert = xdc.useModule('xdc.runtime.Assert');
var Error = xdc.useModule('xdc.runtime.Error');
var Log = xdc.useModule('xdc.runtime.Log');

var Main = xdc.useModule('xdc.runtime.Main');
var Memory = xdc.useModule('xdc.runtime.Memory')
var SysMin = xdc.useModule('xdc.runtime.SysMin');
var System = xdc.useModule('xdc.runtime.System');
var Text = xdc.useModule('xdc.runtime.Text');

var BIOS = xdc.useModule('ti.sysbios.BIOS');
var Hwi = xdc.useModule('ti.sysbios.family.arm.a8.intcps.Hwi');
var Hwi2 = xdc.useModule('ti.sysbios.hal.Hwi');

var Task = xdc.useModule('ti.sysbios.knl.Task');
var Event = xdc.useModule('ti.sysbios.knl.Event');
var Idle = xdc.useModule('ti.sysbios.knl.Idle');
var Clock = xdc.useModule('ti.sysbios.knl.Clock');
var Mmu = xdc.useModule('ti.sysbios.family.arm.a8.Mmu');
var Cache = xdc.useModule('ti.sysbios.family.arm.a8.Cache');

// var TimerProvider = xdc.useModule('ti.sysbios.timers.dmtimer.TimestampProvider');
var TimerProvider = xdc.useModule('ti.sysbios.family.arm.a8.TimestampProvider');

var HeapBuf = xdc.useModule('ti.sysbios.heaps.HeapBuf');
var HeapMultiBuf = xdc.useModule('ti.sysbios.heaps.HeapMultiBuf');
var HeapMem = xdc.useModule('ti.sysbios.heaps.HeapMem');


Task.addHookSet({
        switchFxn: "&onTaskSwitch",
});

System.extendedFormats += "%f";

/*
 * Minimize exit handler array in System.  The System module includes
 * an array of functions that are registered with System_atexit() to be
 * called by System_exit().
 */
System.maxAtexitHandlers = 4;

/* 
 * Uncomment this line to disable the Error print function.
 * We lose error information when this is disabled since the errors are
 * not printed.  Disabling the raiseHook will save some code space if
 * your app is not using System_printf() since the Error_print() function
 * calls System_printf().
Error.raiseHook = null;
 */

/*
 * Uncomment this line to keep Error, Assert, and Log strings from being
 * loaded on the target.  These strings are placed in the .const section.
 * Setting this parameter to false will save space in the .const section.
 * Error, Assert and Log message will print raw ids and args instead of
 * a formatted message.
Text.isLoaded = false;
 */

/*
 * Uncomment this line to disable the output of characters by SysMin
 * when the program exits.  SysMin writes characters to a circular buffer.
 * This buffer can be viewed using the SysMin Output view in ROV.
SysMin.flushAtExit = false;
 */
SysMin.flushAtExit = true;

// place the entry point at the beginning (buggy)
Program.sectMap[".c_int00"] = new Program.SectionSpec();
Program.sectMap[".c_int00"].runAddress = 0x80000000;

/*
 * The BIOS module will create the default heap for the system.
 * Specify the size of this default heap.
 */
// text + bss < 4700kB
//var textAndBss = 5 * 1024 * 1024;
var textAndBss = 25 * 1024 * 1024;
var totalRam = 0x20000000;
BIOS.heapSize = totalRam - textAndBss;

var heapSection = new Program.SectionSpec();
//heapSection.runAddress = 0x80000000 + totalRam - BIOS.heapSize;
heapSection.type = "NOLOAD";
Program.sectMap["system.heap"] = heapSection;
BIOS.heapSection = "system.heap"
// Remove section to exclude 0's for heap initialization from ARM image.
// Must have corresponding NOLOAD specifier for this section in linker command file.
Program.sectionsExclude = "system.heap";

// use HeapTrack for the default heap
BIOS.heapTrackEnabled = false;

/* System stack size (used by ISRs and Swis) */
Program.stack = 4 * 1024;

/* Circular buffer size for System_printf() */
SysMin.bufSize = 8 * 1024;

System.SupportProxy = SysMin;
SysMin.outputFxn = "&Uart_write";
Error.raiseHook = "&onSystemError";

BIOS.swiEnabled = true;
BIOS.taskEnabled = true;

/* Set up MMU for peripheral addresses */
Mmu.enableMMU = true;

// Force peripheral section to be NON cacheable strongly-ordered memory
var attrs = {
        type: Mmu.FirstLevelDesc_SECTION, // SECTION descriptor
        tex: 0,
        bufferable: false,                // bufferable
        cacheable: false,                // cacheable
        shareable: false,                // shareable
        noexecute: true,                 // not executable
};

for (var addr = 0x44000000; addr < 0x57000000; addr += 0x00100000) {
        Mmu.setFirstLevelDescMeta(addr, addr, attrs);
}

Task.checkStackFlag = false;
Hwi2.checkStackFlag = false;

Task.deleteTerminatedTasks = false;

Clock.swiPriority = 10;
// Dynamic mode seems to have more accurate timing
// BUT! it seriously reduces the amount of CPU available before clicks/pops and completely breaks ADC at low buffer sizes.
// Clock.tickMode = Clock.TickMode_DYNAMIC;

var Load = xdc.useModule('ti.sysbios.utils.Load');
Load.windowInMs = 1000;
Load.taskEnabled = true;
//Clock.timerId = 5;
Clock.tickPeriod = 1000;

And for completeness, here is the linker file and cfg file that I normally use but has the problem where I need to hardcode the size/location of the heap but at least the generated bin file matches the size of text+bss (3.9MB in my case):

/*
 * This file was generated by linkcmd_bm_v7a.xdt from the gnu.target.arm  package.
 */

ENTRY(_c_int00)

__TI_STACK_SIZE = 0x1000;
__STACK_SIZE = __TI_STACK_SIZE;

__HEAP_SIZE = 0x0;

INPUT(
    "/home/clarkson/projects/er-301/bin/firmware/sysbios/package/cfg/release_pa8fg.oa8fg"
    "/home/clarkson/projects/er-301/bin/firmware/sysbios/package/cfg/release_pa8fg.src/sysbios/sysbios.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/gnu.targets.arm.rtsv7A.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/boot.aa8fg"
    "/home/clarkson/ti-old/bios_6_46_05_55/packages/gnu/targets/arm/rtsv7A/lib/syscalls.aa8fg"
)

MEMORY
{
    SRAM (RWX) : org = 0x402f0400, len = 0x1fbff
    DDR3 (RWX) : org = 0x80000000, len = 0x20000000
}

/*
 * In order to put the .bass, .text, .data, .heap or .stack into a
 * different memory section, change the corresponding REGION_ALIAS.
 */
REGION_ALIAS("REGION_BSS", DDR3);
REGION_ALIAS("REGION_TEXT", DDR3);
REGION_ALIAS("REGION_DATA", DDR3);
REGION_ALIAS("REGION_STACK", DDR3);
REGION_ALIAS("REGION_HEAP", DDR3);
REGION_ALIAS("REGION_ARM_EXTAB", DDR3);
REGION_ALIAS("REGION_ARM_EXIDX", DDR3);

/*
 * symbolic aliases for static instance objects
 */
xdc_runtime_Startup__EXECFXN__C = 1;
xdc_runtime_Startup__RESETFXN__C = 1;

/*
 * Linker command file contributions from all loaded packages:
 */

/* Content from ti.sysbios.family.arm (ti/sysbios/family/arm/linkcmd.xdt): */

/* Content from ti.sysbios.rts (ti/sysbios/rts/linkcmd.xdt): */

/* Content from ti.sysbios.family.arm.a8.intcps (ti/sysbios/family/arm/a8/intcps/linkcmd.xdt): */
ti_sysbios_family_arm_a8_intcps_Hwi_intc = 0x48200000;


SECTIONS {

        .c_int00 0x80000000 : {*(.c_int00)} 
    system.heap 0x81900000 (NOLOAD) : {*(system.heap)} 
    .vecs : {*(.vecs)}  AT> DDR3
    ti.sysbios.family.arm.a8.mmuTableSection (NOLOAD) : {*(ti.sysbios.family.arm.a8.mmuTableSection)}  AT> DDR3
    xdc.meta (COPY) : {KEEP(*(xdc.meta))}  AT> DDR3


    .c_int00 : {
        KEEP (*(.c_int00))
    } > REGION_TEXT

    .text : {
        CREATE_OBJECT_SYMBOLS
        KEEP (*(.resetVecs))
        KEEP (*(.text))
        *(.text.*)
        *(.gnu.linkonce.t*)
        *(.gnu.warning)
        *(.glue*)
        . = ALIGN(0x4);
        KEEP (*(.ctors))
        *(.gnu.linkonce.r.*)
        . = ALIGN(0x4);
        __init_array_start = .;
        KEEP(*(SORT(.init_array.*)))
        KEEP(*(.init_array))
        __init_array_end = .;
        *(.init)
        *(.fini*)
    } > REGION_TEXT

    .rodata : {
        *(.rodata)
        *(.rodata.*)
    } > REGION_TEXT

    .ARM.extab : {
        *(.ARM.extab*)
        *(.gnu.linkonce.armextab.*)
    } > REGION_ARM_EXTAB

    .ARM.exidx : {
        __exidx_start = .;
        *(.ARM.exidx*)
        *(.gnu.linkonce.armexidx.*)
        __exidx_end = .;
    } > REGION_ARM_EXIDX

    etext   = .;
    _etext  = .;
    __etext = .;

    .data : {
        __data_load__ = LOADADDR (.data);
        __data_start__ = .;
        *(.got.plt)
        *(.got)
        *(.shdata)
        KEEP (*(.data))
        KEEP (*(.data*))
        *(.gnu.linkonce.d.*)
        . = ALIGN (4);
        __data_end__ = .;
    } > REGION_DATA AT> REGION_TEXT

    /*
     * Place .heap section before .bss and .stack as the _sbrk
     * implementation in librdimon.a compares the (heap_end + incr)
     * to the current SP value to check if the heap has overlapped
     * with the stack. 
     *
     * If .heap is placed between .bss and .stack in a SYS/BIOS app,
     * when the task stack (allocated in .bss) is the current stack,
     * the heap check in _sbrk will fail and trigger an error even
     * though the heap might not have actually overlapped with the
     * system stack.
     */
    .heap : ALIGN(0x100) {
        __heap_start__ = .;
        end = __heap_start__;
        _end = end;
        __end = end;
        . += __HEAP_SIZE;
        __heap_end__ = .;
        __HeapLimit = __heap_end__;
    } > REGION_HEAP

    .bss : {
        __bss_start__ = .;
        *(.shbss)
        KEEP (*(.bss))
        *(.bss.*)
        *(.gnu.linkonce.b.*)
        *(COMMON)
        . = ALIGN (4);
        __bss_end__ = .;
    } > REGION_BSS

    .stack : ALIGN(0x0008) {
        __TI_STACK_BASE = .;
        __stack = .;
        . += __TI_STACK_SIZE;
    } > REGION_STACK

    .stab           0 : { *(.stab) }
    .stabstr        0 : { *(.stabstr) }
    .stab.excl      0 : { *(.stab.excl) }
    .stab.exclstr   0 : { *(.stab.exclstr) }
    .stab.index     0 : { *(.stab.index) }
    .stab.indexstr  0 : { *(.stab.indexstr) }
    .comment        0 : { *(.comment) }

    .debug          0 : { *(.debug) }
    .line           0 : { *(.line)  }
    .debug_srcinfo  0 : { *(.debug_srcinfo) }
    .debug_sfnames  0 : { *(.debug_sfnames) }
    .debug_aranges  0 : { *(.debug_aranges) }
    .debug_pubnames 0 : { *(.debug_pubnames) }
    .debug_info     0 : { *(.debug_info) }
    .debug_abbrev   0 : { *(.debug_abbrev) }
    .debug_line     0 : { *(.debug_line) }
    .debug_frame    0 : { *(.debug_frame) }
    .debug_str      0 : { *(.debug_str) }
    .debug_loc      0 : { *(.debug_loc) }
    .debug_macinfo  0 : { *(.debug_macinfo) }
    .debug_weaknames    0 : { *(.debug_weaknames) }
    .debug_funcnames    0 : { *(.debug_funcnames) }
    .debug_typenames    0 : { *(.debug_typenames) }
    .debug_varnames     0 : { *(.debug_varnames) }
    .debug_pubtypes     0 : { *(.debug_pubtypes) }
    .debug_ranges       0 : { *(.debug_ranges) }

}

/* function aliases */
xdc_runtime_System_asprintf_va__E = xdc_runtime_System_asprintf_va__F;
xdc_runtime_System_snprintf_va__E = xdc_runtime_System_snprintf_va__F;
xdc_runtime_System_printf_va__E = xdc_runtime_System_printf_va__F;
xdc_runtime_System_aprintf_va__E = xdc_runtime_System_aprintf_va__F;
xdc_runtime_System_sprintf_va__E = xdc_runtime_System_sprintf_va__F;

and the cfg file:

// Configuration shared by all builds of SYS/BIOS.

var Defaults = xdc.useModule('xdc.runtime.Defaults');
var Diags = xdc.useModule('xdc.runtime.Diags');
var Assert = xdc.useModule('xdc.runtime.Assert');
var Error = xdc.useModule('xdc.runtime.Error');
var Log = xdc.useModule('xdc.runtime.Log');

var Main = xdc.useModule('xdc.runtime.Main');
var Memory = xdc.useModule('xdc.runtime.Memory')
var SysMin = xdc.useModule('xdc.runtime.SysMin');
var System = xdc.useModule('xdc.runtime.System');
var Text = xdc.useModule('xdc.runtime.Text');

var BIOS = xdc.useModule('ti.sysbios.BIOS');
var Hwi = xdc.useModule('ti.sysbios.family.arm.a8.intcps.Hwi');
var Hwi2 = xdc.useModule('ti.sysbios.hal.Hwi');

var Task = xdc.useModule('ti.sysbios.knl.Task');
var Event = xdc.useModule('ti.sysbios.knl.Event');
var Idle = xdc.useModule('ti.sysbios.knl.Idle');
var Clock = xdc.useModule('ti.sysbios.knl.Clock');
var Mmu = xdc.useModule('ti.sysbios.family.arm.a8.Mmu');
var Cache = xdc.useModule('ti.sysbios.family.arm.a8.Cache');

// var TimerProvider = xdc.useModule('ti.sysbios.timers.dmtimer.TimestampProvider');
var TimerProvider = xdc.useModule('ti.sysbios.family.arm.a8.TimestampProvider');

var HeapBuf = xdc.useModule('ti.sysbios.heaps.HeapBuf');
var HeapMultiBuf = xdc.useModule('ti.sysbios.heaps.HeapMultiBuf');
var HeapMem = xdc.useModule('ti.sysbios.heaps.HeapMem');


Task.addHookSet({
        switchFxn: "&onTaskSwitch",
});

System.extendedFormats += "%f";

/*
 * Minimize exit handler array in System.  The System module includes
 * an array of functions that are registered with System_atexit() to be
 * called by System_exit().
 */
System.maxAtexitHandlers = 4;

/* 
 * Uncomment this line to disable the Error print function.
 * We lose error information when this is disabled since the errors are
 * not printed.  Disabling the raiseHook will save some code space if
 * your app is not using System_printf() since the Error_print() function
 * calls System_printf().
Error.raiseHook = null;
 */

/*
 * Uncomment this line to keep Error, Assert, and Log strings from being
 * loaded on the target.  These strings are placed in the .const section.
 * Setting this parameter to false will save space in the .const section.
 * Error, Assert and Log message will print raw ids and args instead of
 * a formatted message.
Text.isLoaded = false;
 */

/*
 * Uncomment this line to disable the output of characters by SysMin
 * when the program exits.  SysMin writes characters to a circular buffer.
 * This buffer can be viewed using the SysMin Output view in ROV.
SysMin.flushAtExit = false;
 */
SysMin.flushAtExit = true;

// place the entry point at the beginning (buggy)
Program.sectMap[".c_int00"] = new Program.SectionSpec();
Program.sectMap[".c_int00"].runAddress = 0x80000000;

/*
 * The BIOS module will create the default heap for the system.
 * Specify the size of this default heap.
 */
// text + bss < 4700kB
//var textAndBss = 5 * 1024 * 1024;
var textAndBss = 25 * 1024 * 1024;
var totalRam = 0x20000000;
BIOS.heapSize = totalRam - textAndBss;

var heapSection = new Program.SectionSpec();
heapSection.runAddress = 0x80000000 + totalRam - BIOS.heapSize;
heapSection.type = "NOLOAD";
Program.sectMap["system.heap"] = heapSection;
BIOS.heapSection = "system.heap"

// use HeapTrack for the default heap
BIOS.heapTrackEnabled = false;

/* System stack size (used by ISRs and Swis) */
Program.stack = 4 * 1024;

/* Circular buffer size for System_printf() */
SysMin.bufSize = 8 * 1024;

System.SupportProxy = SysMin;
SysMin.outputFxn = "&Uart_write";
Error.raiseHook = "&onSystemError";

BIOS.swiEnabled = true;
BIOS.taskEnabled = true;

/* Set up MMU for peripheral addresses */
Mmu.enableMMU = true;

// Force peripheral section to be NON cacheable strongly-ordered memory
var attrs = {
        type: Mmu.FirstLevelDesc_SECTION, // SECTION descriptor
        tex: 0,
        bufferable: false,                // bufferable
        cacheable: false,                // cacheable
        shareable: false,                // shareable
        noexecute: true,                 // not executable
};

for (var addr = 0x44000000; addr < 0x57000000; addr += 0x00100000) {
        Mmu.setFirstLevelDescMeta(addr, addr, attrs);
}

Task.checkStackFlag = false;
Hwi2.checkStackFlag = false;

Task.deleteTerminatedTasks = false;

Clock.swiPriority = 10;
// Dynamic mode seems to have more accurate timing
// BUT! it seriously reduces the amount of CPU available before clicks/pops and completely breaks ADC at low buffer sizes.
// Clock.tickMode = Clock.TickMode_DYNAMIC;

var Load = xdc.useModule('ti.sysbios.utils.Load');
Load.windowInMs = 1000;
Load.taskEnabled = true;
//Clock.timerId = 5;
Clock.tickPeriod = 1000;

Hi, 

I think you need to add a custom linker command file to the build, e.g.

SECTIONS
{

    /*
    Remove section to exclude0's for heap initialization from ARM image.
    Must have corresponding "Program.sectionsExclude" in SYSBIOS configuration file.
    */
    .ddrHeap (NOLOAD):
    {
        *(.myHeap) 
    } > DDR2
}

It looks like you are changing the order of the sections by excluding the heap section from the cfg-generated part of the linker script and forcing it to be placed in another (relative) location that is specified in a custom linker script?  I can see that working and I will try it.  I just have to figure out how to do add a custom linker command file to my non-CCS/gnu-make build system.

However, even if the above works it still leaves the bigger problem of how to specify the heap size without hard-coding it, right?

Probably I'm not understanding the problem.

The heap size needs to be set somewhere. How would it not be "hard-coded"? If it weren't hard-coded, where would it be set? Note this is the total (maximum) space allocated for the run-time heap, and more or less of the heap will be consumed depending on how the application uses it. The maximum size can be adjusted according to application requirements.

Using the above method, the linker can determine the best location for the heap in in the desired memory area.

Ideally the bin file shouldn't not be impacted by the size or location of the heap.

As I said before, I've looped in a colleague who may be able to provide more ideas.

Regards,
Frank 

You would use symbols defined in the linker script.  For example, you would define 2 symbols in the linker script, one for the beginning of the heap and one for the end of the heap.  Then the heap management code would use the distance between these symbols as the heap size.  Another example, if all fixed-size sections were placed contiguously in memory starting at the beginning then you can a define a symbol that points to the location right after the last section.  Then the heap just extends to the end of the memory and then only the total size of RAM is hard-coded.

Oh!  This looks like exactly what I want!  Thank you, Todd.

I'll try this out today and get back to you.  By the way, just so I understand what is going on. 

Q1) In the last 2 lines, did you create a *new* global variable, called heap0, and then point the defaultHeapInstance to it?  Or does the global variable, heap0, already exist and thus has a special meaning to BIOS?

Q2) Memory.defaultHeapInstance is used by the RTS for calls to malloc/free?

Q3) Declaring linker symbols requires using a custom linker script and is not possible in the cfg script?