pxe: move hardwired DHCP options into high memory

If we have hardwired DHCP options, move them into high memory instead
of into the trackbuf.  This eliminates yet another trackbuf user.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/core/init.inc b/core/init.inc
index e0ffd23..5cb8e49 100644 (file)
--- a/core/init.inc
+++ b/core/init.inc
@@ -23,6 +23,11 @@ common_init:
                ; Initialize PM invocation framework
                call pm_init
 
+%if IS_PXELINUX
+               ; Save derivative-specific data
+               pm_call pm_save_data
+%endif
+
                ; Decompress PM code to its target location
                pm_call pm_decompress
                cmp eax,__pm_code_len

diff --git a/core/layout.inc b/core/layout.inc
index c58c0fd..2484392 100644 (file)
--- a/core/layout.inc
+++ b/core/layout.inc
@@ -97,6 +97,8 @@ RBFG_brainfuck:       resb 2048               ; Bigger than an Ethernet packet...
                ; the spillover from the last fractional sector load.
                section .uibss          write nobits align=16
 
+               section .savedata       write nobits align=16
+
                ; Symbols from linker script
 %macro SECINFO 1
                extern __%1_start, __%1_lma, __%1_end

diff --git a/core/pxelinux.asm b/core/pxelinux.asm
index e59a0e2..c7d3889 100644 (file)
--- a/core/pxelinux.asm
+++ b/core/pxelinux.asm
@@ -154,54 +154,6 @@ _start1:
 
                lss esp,[BaseStack]
                sti                     ; Stack set up and ready
-;
-; Move the hardwired DHCP options (if present) to a safe place...
-;
-bdhcp_copy:
-               mov cx,[bdhcp_len]
-               mov ax,trackbufsize/2
-               jcxz .none
-               cmp cx,ax
-               jbe .oksize
-               mov cx,ax
-               mov [bdhcp_len],ax
-.oksize:
-               mov eax,[bdhcp_offset]
-               add eax,_start
-               mov si,ax
-               and si,000Fh
-               shr eax,4
-               push ds
-               mov ds,ax
-               mov di,trackbuf
-               add cx,3
-               shr cx,2
-               rep movsd
-               pop ds
-.none:
-
-adhcp_copy:
-               mov cx,[adhcp_len]
-               mov ax,trackbufsize/2
-               jcxz .none
-               cmp cx,ax
-               jbe .oksize
-               mov cx,ax
-               mov [adhcp_len],ax
-.oksize:
-               mov eax,[adhcp_offset]
-               add eax,_start
-               mov si,ax
-               and si,000Fh
-               shr eax,4
-               push ds
-               mov ds,ax
-               mov di,trackbuf+trackbufsize/2
-               add cx,3
-               shr cx,2
-               rep movsd
-               pop ds
-.none:
 
 ;
 ; Initialize screen (if we're using one)
@@ -284,10 +236,55 @@ enter_command:
 auto_boot:
                pm_call hello
 
+;
+; Save hardwired DHCP options.  This is done before the C environment
+; is initialized, so it has to be done in assembly.
+;
+%define MAX_DHCP_OPTS  4096
+               bits 32
+
+               section .savedata
+               global bdhcp_data, adhcp_data
+bdhcp_data:    resb MAX_DHCP_OPTS
+adhcp_data:    resb MAX_DHCP_OPTS
+
+               section .textnr
+pm_save_data:
+               mov eax,MAX_DHCP_OPTS
+               movzx ecx,word [bdhcp_len]
+               cmp ecx,eax
+               jna .oksize
+               mov ecx,eax
+               mov [bdhcp_len],ax
+.oksize:
+               mov esi,[bdhcp_offset]
+               add esi,_start
+               mov edi,bdhcp_data
+               add ecx,3
+               shr ecx,2
+               rep movsd
+
+adhcp_copy:
+               movzx ecx,word [adhcp_len]
+               cmp ecx,eax
+               jna .oksize
+               mov ecx,eax
+               mov [adhcp_len],ax
+.oksize:
+               mov esi,[adhcp_offset]
+               add esi,_start
+               mov edi,adhcp_data
+               add ecx,3
+               shr ecx,2
+               rep movsd
+               ret
+
+               bits 16
+
 ; As core/ui.inc used to be included here in core/pxelinux.asm, and it's no
 ; longer used, its global variables that were previously used by
 ; core/pxelinux.asm are now declared here.
-               section .bss16
+               section .bss16
                alignb 4
 Kernel_EAX     resd 1
 Kernel_SI      resw 1

diff --git a/core/syslinux.ld b/core/syslinux.ld
index 81d6b11..c58851b 100644 (file)
--- a/core/syslinux.ld
+++ b/core/syslinux.ld
@@ -376,6 +376,8 @@ SECTIONS
 
        /* Very large objects which don't need to be zeroed */
 
+       . = ALIGN(128);
+
        __hugebss_vma = .;
        __hugebss_lma = .;              /* Dummy */
        .hugebss (NOLOAD) : AT (__hugebss_lma) {
@@ -387,6 +389,19 @@ SECTIONS
        __hugebss_len = ABSOLUTE(__hugebss_end) - ABSOLUTE(__hugebss_start);
        __hugebss_dwords = (__hugebss_len + 3) >> 2;
 
+       /* Data saved away before bss initialization */
+       . = ALIGN(128);
+
+       __savedata_vma = .;
+       __savedata_lma = .;             /* Dummy */
+       .savedata (NOLOAD) : AT (__savedata_lma) {
+               __savedata_start = .;
+               *(.savedata)
+               *(.savedata.*)
+               __savedata_end = .;
+       }
+       __savedata_len = ABSOLUTE(__savedata_end) - ABSOLUTE(__savedata_start);
+       __savedata_dwords = (__savedata_len + 3) >> 2;
 
        /* XXX: This stack should be unified with the COM32 stack */
        __stack_vma = .;