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* docs/grub-dev.texi: Document stack and heap sizes.

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Vladimir Serbinenko 2013-11-22 12:03:44 +01:00
parent 3937bd962b
commit 095bb1bfa5
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ChangeLog
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@ -1,3 +1,7 @@
2013-11-22 Vladimir Serbinenko <phcoder@gmail.com>
* docs/grub-dev.texi: Document stack and heap sizes.
2013-11-22 Vladimir Serbinenko <phcoder@gmail.com>
* include/grub/i386/pc/memory.h: Decrease

67
docs/grub-dev.texi
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@ -79,6 +79,7 @@ This edition documents version @value{VERSION}.
* Contributing Changes::
* Porting::
* Error Handling::
* Stack and heap size::
* BIOS port memory map::
* Video Subsystem::
* PFF2 Font File Format::
@ -906,6 +907,69 @@ if (grub_errno != GRUB_ERR_NONE)
grub_error_pop ();
@end example
@node Stack and heap size
@chapter Stack and heap size
On emu stack and heap are just normal host OS stack and heap. Stack is typically
8 MiB although it's OS-dependent.
On i386-pc, i386-coreboot, i386-qemu and i386-multiboot the stack is 60KiB.
All available space between 1MiB and 4GiB marks is part of heap.
On *-xen stack is 4MiB. If compiled for x86-64 with GCC 4.4 or later adressable
space is unlimited. When compiled for x86-64 with older GCC version adressable
space is limited to 2GiB. When compiling for i386 adressable space is limited
to 4GiB. All adressable pages except the ones for stack, GRUB binary, special
pages and page table are in the heap.
On *-efi GRUB uses same stack as EFI. If compiled for x86-64 with GCC 4.4 or
later adressable space is unlimited. When compiled for x86-64 with older GCC
version adressable space is limited to 2GiB. For all other platforms adressable
space is limited to 4GiB. GRUB allocates pages from EFI for its heap, at most
1.6 GiB.
On i386-ieee1275 and powerpc-ieee1275 GRUB uses same stack as IEEE1275.
It allocates at most 32MiB for its heap.
On sparc64-ieee1275 stack is 256KiB and heap is 2MiB.
On mips(el)-qemu_mips and mipsel-loongson stack is 2MiB (everything below
GRUB image) and everything above GRUB image (from 2MiB + kernel size)
until 256MiB is part of heap.
On mips-arc stack is 2MiB (everything below GRUB image) and everything above
GRUB image(from 2MiB + kernel size) until 128MiB is part of heap.
On mipsel-arc stack is 2MiB (everything below GRUB image which is not part
of ARC) and everything above GRUB image (from 7MiB + kernel size)
until 256MiB is part of heap.
On arm-uboot stack is 256KiB and heap is 2MiB.
In short:
@multitable @columnfractions .15 .25 .5
@headitem Platform @tab Stack @tab Heap
@item emu @tab 8 MiB @tab ?
@item i386-pc @tab 60 KiB @tab < 4 GiB
@item i386-coreboot @tab 60 KiB @tab < 4 GiB
@item i386-multiboot @tab 60 KiB @tab < 4 GiB
@item i386-qemu @tab 60 KiB @tab < 4 GiB
@item *-efi @tab ? @tab < 1.6 GiB
@item i386-ieee1275 @tab ? @tab < 32 MiB
@item powerpc-ieee1275 @tab ? @tab < 32 MiB
@item sparc64-ieee1275 @tab 256KiB @tab 2 MiB
@item arm-uboot @tab 256KiB @tab 2 MiB
@item mips(el)-qemu_mips @tab 2MiB @tab 253 MiB
@item mipsel-loongson @tab 2MiB @tab 253 MiB
@item mips-arc @tab 2MiB @tab 125 MiB
@item mipsel-arc @tab 2MiB @tab 248 MiB
@item x86_64-xen (GCC >= 4.4) @tab 4MiB @tab unlimited
@item x86_64-xen (GCC < 4.4) @tab 4MiB @tab < 2GiB
@item i386-xen @tab 4MiB @tab < 4GiB
@end multitable
@node BIOS port memory map
@chapter BIOS port memory map
@c By Yoshinori K Okuji
@ -917,9 +981,8 @@ grub_error_pop ();
@item ? @tab 0x2000 - 1 @tab Real mode stack
@item 0x7C00 @tab 0x7D00 - 1 @tab Boot sector
@item 0x8000 @tab ? @tab GRUB kernel
@item 0x68000 @tab 0x78000 - 1 @tab Disk buffer
@item 0x68000 @tab 0x71000 - 1 @tab Disk buffer
@item ? @tab 0x80000 - 1 @tab Protected mode stack
@item 0x80000 @tab ? @tab Heap
@item ? @tab 0xA0000 - 1 @tab Extended BIOS Data Area
@item 0xA0000 @tab 0xC0000 - 1 @tab Video RAM
@item 0xC0000 @tab 0x100000 - 1 @tab BIOS