diff options
| -rw-r--r-- | src/arch/i386/prefix/romprefix.S | 170 |
1 files changed, 119 insertions, 51 deletions
diff --git a/src/arch/i386/prefix/romprefix.S b/src/arch/i386/prefix/romprefix.S index 80d3894c..2858cb3f 100644 --- a/src/arch/i386/prefix/romprefix.S +++ b/src/arch/i386/prefix/romprefix.S @@ -16,7 +16,14 @@ FILE_LICENCE ( GPL2_OR_LATER ) #define STACK_MAGIC ( 'L' + ( 'R' << 8 ) + ( 'E' << 16 ) + ( 'T' << 24 ) ) #define PNP_GET_BBS_VERSION 0x60 #define PMM_ALLOCATE 0x0000 -#define PMM_DEALLOCATE 0x0002 +#define PMM_FIND 0x0001 +#define PMM_HANDLE_BASE ( ( ( 'F' - 'A' + 1 ) << 26 ) + \ + ( ( 'E' - 'A' + 1 ) << 21 ) + \ + ( ( 'N' - 'A' + 1 ) << 16 ) ) +#define PMM_HANDLE_BASE_IMAGE_SOURCE \ + ( PMM_HANDLE_BASE | 0x00001000 ) +#define PMM_HANDLE_BASE_DECOMPRESS_TO \ + ( PMM_HANDLE_BASE | 0x00002000 ) /* ROM banner timeout. Based on the configurable BANNER_TIMEOUT in * config.h, but converted to a number of (18Hz) timer ticks, and @@ -310,65 +317,44 @@ pmm_scan: movw $init_message_pmm, %si xorw %di, %di call print_message - /* We have PMM and so a 1kB stack: preserve upper register halves */ + /* We have PMM and so a 1kB stack: preserve whole registers */ pushal - /* Calculate required allocation size in %esi */ - movzbl romheader_size, %eax - shll $9, %eax - addl $_textdata_memsz, %eax - orw $0xffff, %ax /* Ensure allocation size is at least 64kB */ - bsrl %eax, %ecx - subw $15, %cx /* Round up and convert to 64kB count */ - movw $1, %si - shlw %cl, %si -pmm_loop: - /* Try to allocate block via PMM */ - pushw $0x0006 /* Aligned, extended memory */ - pushl $0xffffffff /* No handle */ - movzwl %si, %eax - shll $12, %eax - pushl %eax /* Allocation size in paragraphs */ - pushw $PMM_ALLOCATE - lcall *%es:7 - addw $12, %sp - /* Abort if allocation fails */ - testw %dx, %dx /* %ax==0 even on success, since align>=64kB */ - jz pmm_fail - /* If block has A20==1, free block and try again with twice - * the allocation size (and hence alignment). - */ - testw $0x0010, %dx - jz got_pmm - pushw %dx - pushw $0 - pushw $PMM_DEALLOCATE - lcall *%es:7 - addw $6, %sp - addw %si, %si - jmp pmm_loop -got_pmm: /* PMM allocation succeeded */ - movw %dx, ( image_source + 2 ) - movw %dx, %ax - xorw %di, %di - call print_hex_word - movb $( '@' ), %al - call print_character - movw %si, %ax - call print_hex_byte - /* Copy ROM to PMM block */ + /* Allocate image source PMM block */ + movzbl romheader_size, %ecx + shll $5, %ecx + movl $PMM_HANDLE_BASE_IMAGE_SOURCE, %ebx + movw $get_pmm_image_source, %bp + call get_pmm + movl %esi, image_source + jc 1f + /* Copy ROM to image source PMM block */ + pushw %es xorw %ax, %ax movw %ax, %es - movl image_source, %edi + movl %esi, %edi xorl %esi, %esi movzbl romheader_size, %ecx shll $9, %ecx addr32 rep movsb /* PMM presence implies flat real mode */ - movl %edi, decompress_to + popw %es /* Shrink ROM */ movb shrunk_rom_size, %al movb %al, romheader_size -pmm_fail: - /* Restore upper register halves */ +1: /* Allocate decompression PMM block. Round up the size to the + * nearest 128kB and use the size within the PMM handle; this + * allows the same decompression area to be shared between + * multiple iPXE ROMs even with differing build IDs + */ + movl $_textdata_memsz_pgh, %ecx + addl $0x00001fff, %ecx + andl $0xffffe000, %ecx + movl %ecx, %ebx + shrw $12, %bx + orl $PMM_HANDLE_BASE_DECOMPRESS_TO, %ebx + movw $get_pmm_decompress_to, %bp + call get_pmm + movl %esi, decompress_to + /* Restore registers */ popal no_pmm: @@ -436,6 +422,88 @@ no_pmm: lret .size init, . - init +/* Attempt to find or allocate PMM block + * + * Parameters: + * %ecx : size of block to allocate, in paragraphs + * %ebx : PMM handle base + * %bp : routine to check acceptability of found blocks + * %es:0000 : PMM structure + * Returns: + * %ebx : PMM handle + * %esi : allocated block address, or zero (with CF set) if allocation failed + */ +get_pmm: + /* Preserve registers */ + pushl %eax + pushw %di + movw $' ', %di +get_pmm_find: + /* Try to find existing block */ + pushl %ebx /* PMM handle */ + pushw $PMM_FIND + lcall *%es:7 + addw $6, %sp + pushw %dx + pushw %ax + popl %esi + testl %esi, %esi + jz get_pmm_allocate + /* Block found - check acceptability */ + call *%bp + jnc get_pmm_done + /* Block not acceptable - increment handle and retry */ + incl %ebx + jmp get_pmm_find +get_pmm_allocate: + /* Block not found - try to allocate new block */ + pushw $0x0002 /* Extended memory */ + pushl %ebx /* PMM handle */ + pushl %ecx /* Length */ + pushw $PMM_ALLOCATE + lcall *%es:7 + addw $12, %sp + pushw %dx + pushw %ax + popl %esi + movw $'+', %di /* Indicate allocation attempt */ + testl %esi, %esi + jnz get_pmm_done + stc +get_pmm_done: + /* Print block address */ + pushfw + movw %di, %ax + xorw %di, %di + call print_character + movl %esi, %eax + call print_hex_dword + popfw + /* Restore registers and return */ + popw %di + popl %eax + ret + .size get_pmm, . - get_pmm + + /* Check acceptability of image source block */ +get_pmm_image_source: + pushw %es + xorw %ax, %ax + movw %ax, %es + movl build_id, %eax + cmpl %es:build_id(%esi), %eax + je 1f + stc +1: popw %es + ret + .size get_pmm_image_source, . - get_pmm_image_source + + /* Check acceptability of decompression block */ +get_pmm_decompress_to: + clc + ret + .size get_pmm_decompress_to, . - get_pmm_decompress_to + /* * Note to hardware vendors: * @@ -456,7 +524,7 @@ init_message: .ascii "\n" .ascii PRODUCT_NAME .ascii "\n" - .asciz "iPXE (http://ipxe.org) - " + .asciz "iPXE (http://ipxe.org) " .size init_message, . - init_message init_message_pci: .asciz " PCI" |