diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/i386/prefix/pxeprefix.S | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/src/arch/i386/prefix/pxeprefix.S b/src/arch/i386/prefix/pxeprefix.S index f59e347ad..9ccc4a2b5 100644 --- a/src/arch/i386/prefix/pxeprefix.S +++ b/src/arch/i386/prefix/pxeprefix.S @@ -19,6 +19,8 @@ FILE_LICENCE ( GPL2_OR_LATER ) #define EB_MAGIC_1 ( 'E' + ( 't' << 8 ) + ( 'h' << 16 ) + ( 'e' << 24 ) ) #define EB_MAGIC_2 ( 'r' + ( 'b' << 8 ) + ( 'o' << 16 ) + ( 'o' << 24 ) ) +#define PREFIX_STACK_SIZE 2048 + /***************************************************************************** * Entry point: set operating context, print welcome message ***************************************************************************** @@ -46,10 +48,11 @@ _pxe_start: movw %ax, %ds movw $0x40, %ax /* BIOS data segment access */ movw %ax, %fs - /* Set up stack just below 0x7c00 */ - xorw %ax, %ax + /* Set up temporary stack immediately after the iPXE image */ + movw %cs, %ax + addw image_size_pgh, %ax movw %ax, %ss - movl $0x7c00, %esp + movl $PREFIX_STACK_SIZE, %esp /* Clear direction flag, for the sake of sanity */ cld /* Print welcome message */ @@ -60,6 +63,18 @@ _pxe_start: 10: .asciz "PXE->EB:" .previous + /* Image size (for stack placement calculation) */ + .section ".prefix.data", "aw", @progbits +image_size_pgh: + .word 0 + .previous + .section ".zinfo.fixup", "a", @progbits /* Compressor fixups */ + .ascii "ADDW" + .long image_size_pgh + .long 16 + .long 0 + .previous + /***************************************************************************** * Find us a usable !PXE or PXENV+ entry point ***************************************************************************** |