[syslinux] [PATCH 1/1] COMBOOT: add get config file full name
Gene Cumm
gene.cumm at gmail.com
Sun Nov 2 17:25:11 PST 2008
From: Gene Cumm <gene.cumm at gmail.com>
COMBOOT API: Add get config full file name to SYSLINUX
Signed-off-by: Gene Cumm <gene.cumm at gmail.com>
---
Returns the full configuration file name. Int 22h AX 001Eh for now as
it appears that the COMBOOT API is designed to be strictly sequential.
The API gets extended but only implemented (for now) for SYSLINUX in
ldlinux.asm. Implementation and documentation are derived from Int
22h AX 000Eh.
There may be a way to be more efficient (with the push/pop on either
side of the call to open in order to preserve the current di value)
however I'm not sure what registers are available and utilizing the
stack would require changes in all variants.
diff --git a/core/comboot.inc b/core/comboot.inc
index 810d825..22757e7 100644
--- a/core/comboot.inc
+++ b/core/comboot.inc
@@ -1033,6 +1033,18 @@ comapi_getadv:
;
comapi_writeadv equ adv_write
+;
+; INT 22h AX=001Eh Get full name of config file
+;
+%if IS_SYSLINUX
+comapi_configfilefull mov P_ES,cs
+ mov P_BX,ConfigNameFull
+ clc
+ ret
+%else
+comapi_configfilefull equ comapi_err
+%endif
+
section .data
%macro int21 2
@@ -1085,6 +1097,7 @@ int22_table:
dw comapi_shufflerm ; 001B cleanup, shuffle and boot to rm
dw comapi_getadv ; 001C get pointer to ADV
dw comapi_writeadv ; 001D write ADV to disk
+ dw comapi_configfilefull ; 001E get full name of config f
int22_count equ ($-int22_table)/2
APIKeyWait db 0
@@ -1109,3 +1122,4 @@ err_comlarge db 'COMBOOT image too large.', CR, LF, 0
alignb 4
DOSErrTramp resd 33 ; Error trampolines
ConfigName resb FILENAME_MAX
+ConfigNameFull resb FILENAME_MAX ; Can't find a better length definition
diff --git a/core/ldlinux.asm b/core/ldlinux.asm
index c7f6577..859a52e 100644
--- a/core/ldlinux.asm
+++ b/core/ldlinux.asm
@@ -904,15 +904,26 @@ getfattype:
mov eax,[RootDir] ; Make the root directory ...
mov [CurrentDir],eax ; ... the current directory
mov di,syslinux_cfg1
+ push di
call open
+ pop di
jnz .config_open
mov di,syslinux_cfg2
+ push di
call open
+ pop di
jnz .config_open
mov di,syslinux_cfg3
+ push di
call open
+ pop di
jz no_config_file
.config_open:
+ push si
+ mov si,di
+ mov di,ConfigNameFull
+ call strcpy
+ pop si
mov eax,[PrevDir] ; Make the directory with syslinux.cfg .
mov [CurrentDir],eax ; ... the current directory
diff --git a/doc/comboot.txt b/doc/comboot.txt
index ceee93a..ed63e60 100644
--- a/doc/comboot.txt
+++ b/doc/comboot.txt
@@ -908,3 +908,11 @@ AX=001Dh [3.60] Write auxilliary data vector
In a future version, PXELINUX may end up attempting to save
the ADV on the server via TFTP write.
+
+
+AX=001Eh [BETA] Get configuration file full name
+ Input: AX 0000Eh
+ Output: ES:BX null-terminated file name string
+
+ Returns the full name of the configuration file. Note that it is
+ possible that the configuration file doesn't actually exist.
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