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| author | Michael Brown | 2005-04-09 18:14:09 +0200 |
|---|---|---|
| committer | Michael Brown | 2005-04-09 18:14:09 +0200 |
| commit | 1f6dfd7047eab181e93819d99d8b8e1600c8f514 (patch) | |
| tree | 5ec2e3b64e0a14cd9caf7b63cba127b750bc7700 /src/arch/i386/transitions/librm.S | |
| parent | Need to provide sizeof(struct free_base_memory_header) to assembly code. (diff) | |
| download | ipxe-1f6dfd7047eab181e93819d99d8b8e1600c8f514.tar.gz ipxe-1f6dfd7047eab181e93819d99d8b8e1600c8f514.tar.xz ipxe-1f6dfd7047eab181e93819d99d8b8e1600c8f514.zip | |
Allow ourselves to be freed by basemem.c without being damaged.
Diffstat (limited to 'src/arch/i386/transitions/librm.S')
| -rw-r--r-- | src/arch/i386/transitions/librm.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/arch/i386/transitions/librm.S b/src/arch/i386/transitions/librm.S index 5299841c..c915b7ee 100644 --- a/src/arch/i386/transitions/librm.S +++ b/src/arch/i386/transitions/librm.S @@ -8,6 +8,9 @@ /* Drag in local definitions */ #include "librm.h" +/* Drag in FREE_BASEMEM_HEADER_SIZE */ +#include "basemem.h" + /**************************************************************************** * This file defines librm: a block of code that is designed to reside * permanently in base memory and provide the interface between @@ -130,6 +133,19 @@ _librm_start: sym /**************************************************************************** + * Note that the first sizeof(struct free_base_memory_header) bytes of + * librm will get vapourised by free_base_memory(). Since we need + * librm to continue working even when this happens, we put some + * padding here. + * + * We must also ensure that the total size of librm is <1kB, otherwise + * free_base_memory() will stomp somewhere in the middle of us as + * well... + **************************************************************************** + */ + .fill FREE_BASEMEM_HEADER_SIZE, 1, 0 + +/**************************************************************************** * GDT for initial transition to protected mode * * PHYSICAL_CS and PHYSICAL_DS are defined in an external header file. |