Gcc seems to handle passing structs by value if they are 4 bytes in size instead of 3 bytes. So, add a pad byte to struct carattr and struct cursorpos.
Reorganize set_cursor_pos(), verify_scroll(), and handle_1013() so there are less live variables.
Don't inline the VBE functions into the main handler code. Code calling VBE functions are newer and are more likely to provide adequate stack space - inlining can cause more stack usage for older functions (which may be stack constrained).
Signed-off-by: Kevin O'Connor kevin@koconnor.net --- tools/checkstack.py | 2 +- vgasrc/vbe.c | 2 +- vgasrc/vgabios.c | 96 ++++++++++++++++++++++----------------------------- vgasrc/vgabios.h | 4 +- 4 files changed, 45 insertions(+), 59 deletions(-)
diff --git a/tools/checkstack.py b/tools/checkstack.py index 428c296..717de2d 100755 --- a/tools/checkstack.py +++ b/tools/checkstack.py @@ -149,7 +149,7 @@ def calc(): stackusage += int(im.group('num'), 16)
if atstart: - if insn == 'movl %esp,%ebp': + if '%esp' in insn or insn.startswith('leal'): # Still part of initial header continue cur[1] = stackusage diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c index 852edbc..227a244 100644 --- a/vgasrc/vbe.c +++ b/vgasrc/vbe.c @@ -390,7 +390,7 @@ vbe_104fXX(struct bregs *regs) regs->ax = 0x0100; }
-void +void noinline handle_104f(struct bregs *regs) { if (!CONFIG_VGA_VBE) { diff --git a/vgasrc/vgabios.c b/vgasrc/vgabios.c index bca2e9a..58e467d 100644 --- a/vgasrc/vgabios.c +++ b/vgasrc/vgabios.c @@ -115,12 +115,14 @@ get_cursor_shape(u8 page) static void set_cursor_pos(struct cursorpos cp) { + u8 page = cp.page, x = cp.x, y = cp.y; + // Should not happen... - if (cp.page > 7) + if (page > 7) return;
// Bios cursor pos - SET_BDA(cursor_pos[cp.page], (cp.y << 8) | cp.x); + SET_BDA(cursor_pos[page], (y << 8) | x);
// Set the hardware cursor u8 current = GET_BDA(video_page); @@ -128,8 +130,8 @@ set_cursor_pos(struct cursorpos cp) return;
// Calculate the memory address - int address = (GET_BDA(video_pagesize) * cp.page - + (cp.x + cp.y * GET_BDA(video_cols)) * 2); + int address = (GET_BDA(video_pagesize) * page + + (x + y * GET_BDA(video_cols)) * 2); stdvga_set_cursor_pos(address); }
@@ -234,9 +236,9 @@ write_teletype(struct cursorpos *pcp, struct carattr ca) cp.y++; break; case '\t': + ca.car = ' '; do { - struct carattr dummyca = {' ', ca.attr, ca.use_attr}; - vgafb_write_char(cp, dummyca); + vgafb_write_char(cp, ca); cp.x++; } while (cp.x < nbcols && cp.x % 8); break; @@ -261,34 +263,6 @@ write_teletype(struct cursorpos *pcp, struct carattr ca) scroll_one(nbrows, nbcols, cp.page); }
-// Write out a buffer of alternating characters and attributes. -static void -write_attr_string(struct cursorpos *pcp, u16 count, u16 seg, u8 *offset_far) -{ - while (count--) { - u8 car = GET_FARVAR(seg, *offset_far); - offset_far++; - u8 attr = GET_FARVAR(seg, *offset_far); - offset_far++; - - struct carattr ca = {car, attr, 1}; - write_teletype(pcp, ca); - } -} - -// Write out a buffer of characters. -static void -write_string(struct cursorpos *pcp, u8 attr, u16 count, u16 seg, u8 *offset_far) -{ - while (count--) { - u8 car = GET_FARVAR(seg, *offset_far); - offset_far++; - - struct carattr ca = {car, attr, 1}; - write_teletype(pcp, ca); - } -} -
/**************************************************************** * Save and restore bda state @@ -492,24 +466,24 @@ handle_1005(struct bregs *regs) static void verify_scroll(struct bregs *regs, int dir) { - u8 page = GET_BDA(video_page); - struct cursorpos ul = {regs->cl, regs->ch, page}; - struct cursorpos lr = {regs->dl, regs->dh, page}; - + u8 ulx = regs->cl, uly = regs->ch, lrx = regs->dl, lry = regs->dh; u16 nbrows = GET_BDA(video_rows) + 1; - if (lr.y >= nbrows) - lr.y = nbrows - 1; + if (lry >= nbrows) + lry = nbrows - 1; u16 nbcols = GET_BDA(video_cols); - if (lr.x >= nbcols) - lr.x = nbcols - 1; + if (lrx >= nbcols) + lrx = nbcols - 1;
- if (ul.x > lr.x || ul.y > lr.y) + if (ulx > lrx || uly > lry) return;
- u16 nblines = regs->al; - if (!nblines || nblines > lr.y - ul.y + 1) - nblines = lr.y - ul.y + 1; + int nblines = regs->al; + if (!nblines || nblines > lry - uly + 1) + nblines = lry - uly + 1;
+ u8 page = GET_BDA(video_page); + struct cursorpos ul = {ulx, uly, page}; + struct cursorpos lr = {lrx, lry, page}; vgafb_scroll(dir * nblines, regs->bh, ul, lr); }
@@ -1014,17 +988,29 @@ handle_1012(struct bregs *regs) static void noinline handle_1013(struct bregs *regs) { - struct cursorpos cp = {regs->dl, regs->dh, regs->bh}; - // if row=0xff special case : use current cursor position - if (cp.y == 0xff) - cp = get_cursor_pos(cp.page); - u8 flag = regs->al; - if (flag & 2) - write_attr_string(&cp, regs->cx, regs->es, (void*)(regs->bp + 0)); + struct cursorpos cp; + if (regs->dh == 0xff) + // if row=0xff special case : use current cursor position + cp = get_cursor_pos(regs->bh); else - write_string(&cp, regs->bl, regs->cx, regs->es, (void*)(regs->bp + 0)); + cp = (struct cursorpos) {regs->dl, regs->dh, regs->bh}; + + u16 count = regs->cx; + u8 *offset_far = (void*)(regs->bp + 0); + u8 attr = regs->bl; + while (count--) { + u8 car = GET_FARVAR(regs->es, *offset_far); + offset_far++; + if (regs->al & 2) { + attr = GET_FARVAR(regs->es, *offset_far); + offset_far++; + } + + struct carattr ca = {car, attr, 1}; + write_teletype(&cp, ca); + }
- if (flag & 1) + if (regs->al & 1) set_cursor_pos(cp); }
diff --git a/vgasrc/vgabios.h b/vgasrc/vgabios.h index 13e5cce..ff5ec45 100644 --- a/vgasrc/vgabios.h +++ b/vgasrc/vgabios.h @@ -82,10 +82,10 @@ extern int VgaBDF; extern int HaveRunInit; #define SET_VGA(var, val) SET_FARVAR(get_global_seg(), (var), (val)) struct carattr { - u8 car, attr, use_attr; + u8 car, attr, use_attr, pad; }; struct cursorpos { - u8 x, y, page; + u8 x, y, page, pad; }; int vga_bpp(struct vgamode_s *vmode_g); u16 calc_page_size(u8 memmodel, u16 width, u16 height);